Abstract

Femoroacetabular impingement (FAI) is a common cause of hip pain in the young adult. Uncertainty regarding surgical indications, outcome assessment, management preferences and perceptions of the literature exist. We conducted a large international survey assessing the perceptions and demographics of orthopaedic surgeons regarding FAI.

A survey was developed using previous literature, focus groups and a sample-to-redundancy strategy. The survey contained forty-six questions and was emailed to national orthopaedic associations and orthopaedic sports medicine societies for member responses. Members were contacted on multiple occasions to increase response rates.

Nine hundred orthopaedic surgeons from twenty national and international organisations completed the survey. Surgeons responded across 6 continents, 58.2 % from developed nations with 35.4 % having sports fellowship training. North American and European surgeons reported significantly greater exposure to hip arthroscopy during residency and fellowships in comparison to international respondents (48.0% vs. 44.5% vs. 25.6% respectively; p<0.001). Surgeons performing a higher volume of FAI surgery (over 100 cases per year) were significantly more likely to have practiced for more than 20 years (OR 1.91; 95% CI 1.01 to 3.63), be practicing at an academic hospital (OR 2.25; 95% CI 1.22 to 4.15), and have formal arthroscopy training (OR 46.17; 95% CI 20.28 to 105.15). High volume surgeons were over two-fold more likely to practice in North America and Europe (OR 2.26; 95% CI: 1.08 to 4.72).

The exponential rise in the diagnosis and surgical management for FAI appears to be driven largely by experienced surgeons in developed nations. Our analysis suggests that although FAI management is early in the innovation cycle we are at a tipping point towards wider uptake and utilisation. The results of this survey will help guide further research and study.

In spite of its incidence decreasing to 1% nowadays, prosthesis-related infections remain a research, diagnostic, therapeutic and cost-related problem. Early diagnosis, selection of an appropriate surgical strategy, accurate identification of the responsible microorganisms and construction of an appropriate antibiotic regimen are essential elements of any management strategy. Our study aim was firstly to compare the diagnostic accuracy of conventional periprosthetic tissue culture and culture of fluid derived from vortexing and bath sonication of the explanted hardware and secondly to investigate the role of possible metabolic factors affecting the sensitivity of the sonication method.

We investigated 70 patients undergoing revision hip or knee arthroplasty because of loosening of the prostheses, at our institution, between October 2011 and November 2013. Patients’ medical history and demographic characteristics were recorded. We compared the culture of samples obtained by sonication of explanted hip and knee prostheses with conventional culture of periprosthetic tissue for the microbiological diagnosis of prosthetic-joint infection.

Infectious Diseases Society of America (IDSA) Guidelines were used for the definition of prosthetic-joint infection. Thirty-two patients had septic loosening and 38 aseptic loosening (48 hip prostheses and 22 knee prostheses). The sensitivity of sonication fluid culture was 81.25% and the sensitivity of conventional tissue cultures was 56.25% (p-value = 0.043). The sensitivity of the sonication method was statistically higher in obese, diabetic patients, with age above 60, in uncemented arthroplasties and in arthroplasties because of primary osteoarthritis (p-values < 0.05).

The sonication method represents a reliable test for the diagnosis of prosthetic – joint infections with a greater sensitivity than the conventional periprosthetic tissue cultures, especially in obese, diabetic patients, with age above 60, in uncemented arthroplasties and in arthroplasties because of primary osteoarthritis.

There are a number of periprosthetic femoral fracture (PFF) fixation failures. In several cases the effect of fracture configuration on the performance of the chosen fixation method has been underestimated. As a result, fracture movement within the window that seems to promote callus formation has not been achieved and fixations ultimately failed.

This study tested the hypothesis that: PFF configuration and the choice of plate fixation method can be detrimental to healing.

A series of computational models were developed, corroborated against measurements from a series of instrumented laboratory models and in vivo case studies. The models were used to investigate the fixation of different fracture configurations and plate fixation parameters. Surface strain and fracture movement were compared between the constructs.

A strong correlation between the computational and experimental models was found. Computational models showed that unstable fracture configurations increase the stress on the plate fixation. It was found that bridging length plays a pivotal role in the fracture movement. Rigid fixations, where there is clinical evidence of failure, showed low fracture movement in the models (<0.05mm); this could be increased with different screw and plate configurations to promote healing.

In summary our results highlighted the role of fracture configuration in PFF fixations and showed that rigid fixations that suppress fracture movement could be detrimental to healing.

Aims and Objectives

To assess the efficacy of linezolid in the treatment of orthopaedic related infection and the instance of adverse reactions.

Introduction

Early identification and conservative management of paediatric Monteggia fractures has been shown to correlate with good results. Nevertheless, several authors advocate more aggressive management with open reduction and internal fixation (ORIF) for unstable fractures. We herein present the experience of a tertiary paediatric hospital in the management of Monteggia fractures.

Introduction

Lateral humeral condyle fractures account for 17% of the distal humeral condyle fractures. They affect children between 5 and 10 years of age. Recent reports advocate closed reduction and internal fixation for the less displaced fractures.

We report our retrospective multicentre experience of managing periprosthetic knee fractures using locking plates, cemented nails and distal femoral prosthesis. The Aim of this study is to analyze the practicality of management of these injuries using modern methods of fixation or salvation. 62 patients presented to 3 centres between 2003 and 2010. After implementation of inclusion criteria, clinical, radiological and functional outcomes were evaluated in 54 patients, with a minimum follow-up of 6 months. 34 patients were treated with locking plates (10 males, 24 female; mean age 76), 16 with cemented/locking nails (4 males, 12 females; mean age 84.5), and 4 with distal femoral replacement prosthesis (2 males, 2 females; mean age 79).

Locking plates which were used with a minimally invasive pattern produced the best outcomes in our study. A statistical significance of p value of less than 0.01 was found in union time between patients operated on with an open technique (6.69±2.69 months) and those operated on with a minimally invasive technique (3.6±0.91 months). Nailing with augmented cement is a useful technique in patients who are not suitable for challenging surgery & rehabilitation programmes. There was a significant difference in mean time to functional weight bearing (p< 0.01) between the plate group (4.79±2.6 months) and the nail group (2.63±0.5 months). Post-operative range of motion was also better for nails (106.36±14.33^O flexion) compared to plates (93.24±26.8^O), a result that approached significance (p=0.065). We recommend minimal invasive plating in uncompromised physiological conditions, as an ideal method of fracture fixation in view of statistically significant union rates. Cemented nailing is recommended in patients where early rehabilitation is essential. Distal Femoral prosthesis replacement is a useful salvage method.

Tribology and wear of articular cartilage is associated with the mechanical properties, which are governed by the extracellular matrix (ECM). The ECM adapts to resist the loads and motions applied to the tissue. Most investigations take cartilage samples from quadrupeds, where the loading and motions are different to human. However, very few studies have investigated the differences between human and animal femoral head geometry and the mechanical properties of cartilage.

This study assessed the differences between human, porcine, ovine and bovine cartilage from the femoral head; in terms of anatomical geometry, thickness, equilibrium elastic modulus and permeability.

Diameter of porcine (3-6 months old), bovine (18-24 months old), ovine (4 years old) and human femoral heads were measured (n=6). Plugs taken out of the superior region of each femoral head and creep indentation was performed. The human femoral heads were obtained from surgery due to femoral neck fracture. Cartilage thickness was measured by monitoring the resistive force change as a needle traversed the cartilage and bone at a constant feed rate using a mechanical testing machine. The percentage deformation over time was determined by dividing deformation by thickness. A biphasic finite element model was used to obtain the intrinsic material properties of each plug. Data is presented as the mean ± 95% confidence limits. One-way ANOVA was used to test for significant differences (p < or = 0.05).

Significant differences in average femoral head diameter were observed between all animals, where bovine showed the largest femoral head. Human cartilage was found to be significantly thicker than cartilage from all quadrupedal hips. Human cartilage had a significantly larger equilibrium elastic modulus compared to porcine and bovine cartilage. Porcine articular cartilage was measured to be the most permeable which was significantly larger than all the other species. No significant difference in permeability was observed between human and the other two animals: bovine and ovine (Table 1).

The current study has shown that articular cartilage mechanical properties, thickness and geometry of the femoral heads differ significantly between different species. Therefore, it is necessary to consider these variations when choosing animal tissue to represent human.

Objective

Human bone marrow stromal cells (HBMSCs) are multipotent and can form bone, cartilage or other tissues under different inductive conditions. The aim of this study was to investigate the effects of enamel matrix derivative (EMD) on the growth and osteogenic differentiation of HBMSCs.

With the ever increasing rate of total hip replacement and life span of these patients, there has been an upward trend towards the incidence of peri-prosthetic fractures. Previous studies does suggest the implant cost to as high as 30% of the total reimbursement in primary hip arthroplasty but this figure is much higher in periprosthetic fractures where long stem revisions are commonly used

A prospective comparative study analyzing the total cost of hospital stay for a cohort of 52 consecutive patients with peri-prosthetic fractures of long bones treated in two hospitals from October 2007 to march 2009 was conducted. Demographic data, fracture classification and method of surgical treatment along with the length of hospital stay were recorded in detail. The total cost calculated was then compared to the range of reimbursement price based on HRG (human Resource Group) coding. The implant cost was determined from the buying cost by each institution.

52 patients were available for review. Average age of the patients operated was 78.5 years. 69 percent of the peri-prosthetic fractures in our series were around the proximal femur. The average cost of stay was £ 16453 (£ 1425- 26345). The reimbursement to the hospital ranged from £ 1983 to £ 8735.

Hospital source utilization for peri prosthetic fractures is quite high compared to the reimbursement being given to hospitals for treating such patients. This can be as low as £ 1500 as acute phase tariff to £ 9100 for elective revisions and the implant cost can vary from 50% to 200% of the total reimbursement cost. Current recording system for peri-prosthetic fracture is unclear resulting in discrepancy between resource utilization and reimbursement thus resulting in substantial financial losses for hospitals that perform these procedures.

To evaluate efficacy and outcome of embolisation following pelvic ring injuries in patients presented with ongoing hypovolaemic shock.

Between 2000 and 2003, 200 poly-trauma patients presented in our institutions following pelvic ring injuries. Those with ongoing hypovolaemic shock who were treated within 24h of admission with embolisation were included in this study. Demographics, mechanism of injury, ISS, type of pelvic ring fracture, arterial source of bleeding, hours from injury to embolisation, and outcome were all recorded prospectively. Out of the 200 treated in our institutions 17 (8.5%) underwent angio-embolisation. The mean age of the patients was 37 (14-70) and the mean ISS was 29. Distribution of pelvic ring injuries included: 3LC, 7APC, 7VS. The mean time from injury to embolisation was 15 hours. 8/17 patients were initially treated with an external fixator.

The distribution of arterial injuries was: 7 superior gluteal arteries, 8 internal iliac arteries, 1 obturator artery and 1 internal pudental artery. The mean number of units transfused prior to embolisation was 22 (range 6-50). Mortality rate was 4 (23%) out of 17 embolised patients. Angio-embolisation for pelvic ring injuries occurred in 8.5% of our study population.

This study indicates that only a small proportion of patients required embolisation secondary to arterial bleeding. The overall survival rate was in accordance to published international experience. Embolisation should be considered as a valid adjunct in some selected group of patients with pelvic fractures where ongoing bleeding refractory to other treatment modalities is present.

Surgery for pelvic or acetabular fractures carries a high risk of deep-vein thrombosis (DVT). Reports indicate that fondaparinux is a more effective thromboprophylactic agent than low molecular weight heparin (LMWH) after major orthopaedic surgery. We prospectively evaluated a new protocol for DVT prophylaxis using fondaparinux.

Introduction

The aim of this study was to investigate the differences between open vs closed femoral fractures with regard to the epidemiology, classification and outcome.

Background

Acetabular or pelvic ring injuries are invariably associated with high-energy trauma that could lead to a significant degree of disability. The purpose of this study was to investigate whether patients who had surgical treatment of isolated acetabular or pelvic injuries were able to return to their previous sporting activities.

Restoration of an anatomical hip centre frequently requires limb lengthening, which increases the risk of nerve injury in the treatment of Crowe 4 DDH. The objective was to perform a prospective evaluation of SDTSO with Cemented Exeter Femoral Component.

15 female patients (18 hips – 3 bilateral) with a mean age at time of operation of 51 years were followed-up for a mean of 77 months (11 to 133). 16 cemented and 2 uncemented acetabular components were implanted. Exeter cemented DDH stems were used in all cases. No patient was lost to follow-up.

Charnley-d'Aubigné-Postel scores for pain, function and range of movement were improved from a mean of 2, 2, 3 to 5, 4, 5 respectively. One osteotomy failed to unite at 14 months and was revised successfully. Clinical healing was achieved at a mean of 6 months and radiological at a mean of 9 months. The mean length of the excised segment was 3cm and the mean true limb lengthening was 2cm. A 3.5mm DCP plate with unicortical screws was used to reduce the osteotomy, and intramedullary autografting was performed in all cases. Mean subsidence was 1mm and no stem was found loose at the latest follow-up. No sciatic nerve palsy was observed and no dislocation.

Cemented Exeter femoral components perform well in the treatment of Crowe IV DDH with SDTSO. Transverse osteotomy is necessary to achieve derotation and reduction can be maintained with a DCP plate. Intramedullary autografting prevents cement interposition at the osteotomy site.

Comparison of the safety and efficacy of Bilateral Simultaneous Total Hip Arthroplasty (BSTHA) with that of staged (SgTHA) and unilateral (UTHA) was conducted using DerSimonian–Laird heterogeneity meta-analysis. A review of the English-language literature identified 23 citations eligible for inclusion. A total of 2063 bilateral simultaneous THR patients were identified. Meta-analysis of homogenous data revealed that there were no statistically significant differences between rates of thromboembolic events (p=0.268 and p=0.365) and dislocation (p=0.877) when comparing staged or unilateral with bilateral simultaneous THR procedures. A systematic analysis of heterogenous data demonstrated that mean length of hospital stay was shorter after bilateral simultaneous THR. Blood loss was reduced after bilateral simultaneous THR in all studies except for one, and surgical time was not different between groups. This procedure was also found to be economically and functionally efficacious when performed by experienced surgeons in specialist centres.

Periprosthetic femoral fractures around total knee arthroplasty present a challenge in octogenarians with advanced osteoporosis. We describe a salvage technique combining retrograde intramedullary nailing augmented with polymethylmethacrylate (PMMA) cement in five patients followed up for a median time of 12 months. The nail/cement construct bridges the femoral canal tightly and behaves like a stemmed cemented revision component. All patients had an uncomplicated recovery and returned to their pre-injury functional status within four months. This procedure does not disrupt the soft tissue envelope facilitating periosteal callus formation, is easy to perform and permits immediate full range of movement. When standard retrograde nailing or plating alone is inadequate in maintaining severely osteoporotic fracture reduction in octogenarians unfit for lengthy procedures, nailed cementoplasty is proposed as a salvage procedure.

In selected patients in-cement revision of the total hip arthroplasty components is an attractive option. Recommended roughening of the primary mantle surface remains controversial. Aim of the study was to investigate the influence of the cement surface roughening on the strength of bilaminar cement interface.

Flat, laboratory model of bilaminar cement interface was used. Prior to its creation, modeled primary mantle surface was machined to the roughness of either smooth surface observed after removal of a highly polished stem (Ra=200nm) or that following roughening (Ra=5μm). Two viscosities of interfering fluids (water and bone marrow) were also used. 6 variants (smooth or rough, both stained with water, bone marrow or with no fluid) with 7 repeats were exposed to single shear to failure.

No significant difference in resistance to shear was observed between the groups with dry smooth (16.82MPa) and rough surfaces (16.96MPa), and those stained with large volume of low viscosity fluid. In the presence of water, roughening did not significantly influence the interface (smooth – 17.04MPa and rough – 16.25MPa respectively).

In the smooth variant with large volume of viscous fluid, ultimate stress value dropped to 5.53MPa, and 9.87MPa in the roughened group with the same amount of viscous fluid (p< 0.05).

Extra roughening may offer some benefit when performing in-cement revision in the presence of large volume of viscous fluid only though in-cement revision would not be then recommended. In the presence of low viscosity fluids (blood, irrigation fluid) benefit of roughening is dubious.

Controversy still remains as to whether patella resurfacing in total knee arthroplasty (TKA) should be conducted as a matter of routine. Some authors recommend routine resurfacing of the patella and advocate this due to the reduction in post-operative anterior knee pain and the reduction in requirement for revision surgery.

A database search was conducted to identify prospective randomized controlled studies only. Eighteen prospective randomized trials were identified and found eligible for inclusion. A cumulative sample of 8006 knees were involved, 3418 undergoing resurfacing and 4588 undergoing no resurfacing. Primary outcome data extracted was incidence of secondary operations, incidence of anterior knee pain and functional outcome scores including subgroup analysis of the type of prosthesis used in each study. Der Simonian Laird metanalysis was conducted if studies were found to be homogenous where statistical significance was defined as an overall alpha error of < 0.05.

No statistically significant differences were found to exist between patients undergoing patella resurfacing as a primary total knee replacement and those who preserved the native patella. No differences could be found between specific prosthetic design when subgroup analysis was conducted.

The study does not offer evidence to suggest any advantage of resurfacing versus non-resurfacing. Furthermore, no significant discrepancy existed when comparing different types of total knee prosthesis. This may be due that all the knees analysed are designed to be patella friendly and allow conformity of articulation of both a native and patella button equally