Wear rate and medium-term survival of a cemented, moderately cross-linked polyethylene acetabular prosthesis.

INTRODUCTION: The moderately cross-linked Depuy Marathon® cemented acetabular component was introduced into the UK in 2007. The wear rate for the previously introduced Marathon® uncemented acetabular component has been reported to range from 0.06 to 0.01 mm/year. The aim of this study was to present the medium-term results and wear rate of the Marathon® cemented prosthesis used in primary total hip arthroplasty. METHODS: 103 Marathon® cemented acetabular components were implanted between 2008 and 2009 in primary arthroplasty, who were eligible for this study. All patients received a metal 28-mm head. Mean age was 68 years (range 27-87). Mean clinical follow-up was 55 months (range 50-61). Mean radiological follow-up was 46 months (range 24-57). Wear was calculated on AP radiographs using computer-assisted uni-radiographic technique. RESULTS: The mean wear was 0.37 mm (range 0.0-0.78 mm). The wear rate was calculated as 0.03 mm/year (95% confidence interval 0.02-0.06). Postoperative complications included deep vein thrombosis (2%) and dislocation (0.8%); there were no deep infections. There were no revisions for failure of the Marathon® cemented acetabular component. CONCLUSIONS: The Marathon® cemented acetabular component demonstrates satisfactory wear rates and survivorship at medium-term follow-up.

MRI versus computed tomography as an imaging modality for postreduction assessment of irreducible hips in developmental dysplasia of the hip: an interobserver and intraobserver reliability study.

Following surgical reduction of an irreducible hip in developmental dysplasia of the hip, imaging is required to ascertain successful reduction. Recent studies have compared MRI versus computed tomography (CT) in terms of cost, time, sensitivity and specificity. This is the first study to compare intraobserver and interobserver reliability for both modalities. Nineteen CT scans of 38 hips in 10 patients and nine MRI scans of 18 hips in six patients were reviewed on two separate occasions by three clinicians. Image clarity, confidence of diagnosis, time taken to perform the scan as well as radiation dose for CT were recorded. Intraobserver and interobserver reliability κ values were calculated. There were 14 female patients and one male patient. The mean age at the time of the scan was 12 months (range 3-25 months). Intraobserver reliability was greater than 0.8 (both CT and MRI). Interobserver reliability was greater than 0.8 (both CT and MRI). Image clarity was higher for CT for two out of the three clinicians (9.47 vs. 6.33 P<0.05; 9.89 vs. 8.11, P<0.05). All clinicians were equally confident in the diagnosis when using CT or MRI. The time taken to perform the investigation was not significantly different (3.32 vs. 4.88 min, P>0.05). The mean radiation dose for CT was 91.75 DLP (dose length product, mGy×cm) (95% confidence interval±26.95). Our results show that MRI is equal to CT as an imaging modality in the assessment of postreduction hips in developmental dysplasia of the hip. Intraobserver and interobserver reliability was excellent for both. The image clarity was higher for CT, but this method of imaging carries a significant risk of radiation exposure. We recommend that MRI should supersede CT as an imaging modality for this clinical situation.

Mortality Patterns in Patients with Multiple Trauma: A Systematic Review of Autopsy Studies.

PURPOSE: A high percentage (50%-60%) of trauma patients die due to their injuries prior to arrival at the hospital. Studies on preclinical mortality including post-mortem examinations are rare. In this review, we summarized the literature focusing on clinical and preclinical mortality and studies included post-mortem examinations. METHODS: A literature search was conducted using PubMed/Medline database for relevant medical literature in English or German language published within the last four decades (1980-2015). The following MeSH search terms were used in different combinations: "multiple trauma", "epidemiology", "mortality ", "cause of death", and "autopsy". References from available studies were searched as well. RESULTS: Marked differences in demographic parameters and injury severity between studies were identified. Moreover, the incidence of penetrating injuries has shown a wide range (between 4% and 38%). Both unimodal and bimodal concepts of trauma mortality have been favored. Studies have shown a wide variation in time intervals used to analyze the distribution of death. Thus, it is difficult to say which distribution is correct. CONCLUSIONS: We have identified variable results indicating bimodal or unimodal death distribution. Further more stundardized studies in this field are needed. We would like to encourage investigators to choose the inclusion criteria more critically and to consider factors affecting the pattern of mortality.

Development of a scoring system based on conventional parameters to assess polytrauma patients: PolyTrauma Grading Score (PTGS).

BACKGROUND: The impact of conventional laboratory data to identify polytrauma patients at risk of complications is established. However, it has not been assessed in terms of prognostic accuracy for systemic complications (ARDS, organ failure). We therefore assessed the most predictive parameters for systemic complications and developed a scoring system for early grading of polytrauma patients. METHODS: A population based trauma registry was used. INCLUSION CRITERIA: age >16 years, Abbreviated Injury Score (AIS) of the abdomen or chest ≥ 3 points and treatment in an intensive care unit, or Injury Severity Score (ISS) ≥ 16 points. The primary endpoint was hospital mortality. Patients were graded according their risk of death: low risk of death (5-14% mortality), intermediate risk patients (15-39% mortality) and high risk (>40%). Routine clinical and laboratory parameters on admission were assessed to determine their specific relevance to describe the risk profile of the patient. Based on these data, a scoring system for the description of the clinical status was developed. Statistical analysis included uniand multivariate analysis. RESULTS: 11.436 patients were included, the mean ISS was 22.7 ± 11.2 points, 73% were male, and 95.6% had blunt injuries. The most sensitive parameters were found to be the following ones: systolic blood pressure, INR, thrombocytes, base deficit, NISS, packed red blood cells administered. The multivariate analysis revealed the following threshold levels: BP 76-90 mmHg: r = 0.249, OR 1.283: Base deficit 8-10 r = 0.474, OR 1.606; INR 1.4-2 r = 0.160, OR 1.174; NISS 35-39 r = 0.9, OR 2.46; pBRC 3-14: r = 0.671, OR 1.957. The following ranges of score values were found to be associated with different patient status: <6 points: stable patients; 6-11 points: borderline condition; >11 points: unstable patients. When using this score, 80.6% were stable, 14.6% in a borderline condition and 4.8% unstable. CONCLUSION: We developed a scoring system to discriminate polytrauma patients on admission that are at risk of systemic complications. Systolic blood pressure, INR, thrombocytes, base deficit, NISS, packed red blood cells administered are able to provide a prognosis of patients at risk of posttraumatic complications. Further prospective studies should be performed to verify this new scoring system.

Development of a standardized trauma-related lung injury model.

BACKGROUND: The pathophysiology of acute lung injury is multifactorial, and the mechanisms are difficult to prove. We have devised a study of two known and standardized animal models (hemorrhagic shock [HS] and oleic acid [OA]) to more closely reproduce the pathophysiology of posttraumatic acute lung injury. MATERIAL AND METHODS: Pressure-controlled HS (group HS) was performed by withdrawing blood over 15-min until mean arterial pressure reached 35 mm Hg for 90 min. In an additional group, HS and standardized lung injury induced by OA were combined (group lung injury [HS + OA]). After the shock period, both groups were resuscitated over 15 min by transfusion of the removed blood and an equal volume of lactate Ringer solution. The end point was 6 h. Plasma interleukin (IL)-6, keratinocyte chemoattractant (KC), IL-10, monocyte chemoattractant protein-1 (MCP-1), and lung histology were carried out. RESULTS: The posttraumatic lung injury group demonstrated significantly higher IL-6 levels when compared with HS group (744.8 ± 104 versus 297.7 ± 134 pg/mL; P = 0.004). Histologic analysis confirmed diffuse alveolar congestion and moderate-to-severe lung edema in animals with HS + OA. Lung injury was mild in mice with isolated HS or OA injection. CONCLUSIONS: We established a posttraumatic lung injury model combining two different standardized protocols (HS and OA). This model leads to pronounced inflammation and lung injury. This model allows the analysis of the dynamics of sterile lung injury and associated organ dysfunction.

Animal models to assess the local and systemic effects of nailing: review of the literature and considerations for future studies.

BACKGROUND: Numerous experimental studies have been performed to investigate the adverse effects of reamed versus unreamed nailing in isolated or combined trauma models. However, the translational relevance is still discussed controversially. METHODS AND RESULTS: A systemic review of the literature was performed. An increase of intramedullary pressure with liberation of emboli to the venous and systemic circulation associated with reamed and unreamed nailing has been well described. Reamed nailing, however, seems to have superior clinical results in terms of fracture healing. CONCLUSION: The pathophysiologic effects, optimal timing, and technique of reamed nailing particularly in patients with multiple injuries continue to be controversial topics. Therefore, further experimental studies should focus on these topics as well as on the interaction of local and systemic processes particularly in the context of different surgical treatment strategies (Early Total Care vs. Damage Control Orthopaedics) to improve our understanding and approach to intramedullary nailing.

Arthroscopic medial capsular plication using the suture anchor technique.

PURPOSE: The suture anchor technique for medial capsular plication has been previously described. We present our technique and its medium-term results. METHODS: A single surgeon's experience (senior author) of the suture anchor technique for medial capsular plication was reviewed in 14 knees in 14 patients. All patients underwent arthroscopic stabilisation for patello-femoral instability. The method used was the suture anchor technique for medial capsular plication (full technique described in paper). The primary outcome measure used was further dislocation or instability. The validated Kujala score was used pre- and post-op to assess functional outcome. RESULTS: There were nine male and five female patients (M:F, 64%:34%). Median age was 25 (range 16-65). Mean follow-up was 52 months (95% CI 44-56 range 24-72). The mean pre-op Kujala score was 54.6 (SD 24.4). The mean post-op Kujala score was 78.2 (SD 20.5). The mean increase in Kujala score was 23.6 (95% CI 7.9-39.4). There was a statistically significant increase in Kujala score, P=0.006. Only 1 of 14 patients had a further dislocation (7%), and there were no further episodes of instability. CONCLUSION: This is the first paper to describe the results of this technique in the literature. There was a statistically significant improvement in the patients' functional outcome and 13/14 patients did not re-dislocate or experience instability. It was concluded that this technique is a successful mode of treatment for patello-femoral instability. LEVEL OF EVIDENCE: Case series, Level IV.

Isolated talonavicular arthrodesis for talonavicular arthritis: a follow-up study.

We have reviewed a single surgeon's (M.S.) experience of talonavicular arthrodesis in 7 feet in 7 patients with isolated talonavicular arthritis. A standard dorsomedial approach was used to the talonavicular joint. Fixation was performed with 5.5-mm, partially threaded, cancellous screws. The visual analog scale for the foot and ankle (VASFA) was used to measure the preoperative and postoperative results in the categories of pain, function, other complaints, and total score. The follow-up period was 17 to 90 months (mean 48). The overall VASFA score ranged from +19.2 to +57.6 (mean +33.2, p < .01). The VASFA score for pain ranged from +19 to +74.8 (mean +51.3, p < .01). The VASFA score for function ranged from +12.5 to +68.2 (mean +28.3, p < .01). The VASFA score for other problems ranged from +12 to +45.8 (mean +25.5, p < .01). None of the 7 feet required revision, and all 7 patients were satisfied with the outcome and would have the operation again. We have concluded that, taking into account the small power of the present study, talonavicular arthrodesis is a successful treatment for isolated talonavicular arthritis.

MRSA screening in orthopaedic surgery: clinically valuable and cost effective? A prospective analysis of 8,867 patients.

This study aimed at assessing the prevalence of MRSA colonisation in Trauma and Orthopaedics. Risk factors, decolonisation, and subsequent infection rates were investigated. Cost-analysis of the MRSA screening program was performed. The validity and effectiveness of the MRSA screening program was reviewed. A prospective analysis was made of all orthopaedic admissions in East Lancashire Hospital Trust. A total number of 13,155 swabs were taken in 8,867 patients in 2010. This MRSA screening program was compared to the ideal screening criteria set out by Wilson and Junger (WHO 1968). The MRSA prevalence in Trauma and Orthopaedics in 2010 was 0.47%. The decolonisation rate was 55%. There was no correlation between MRSA colonisation and subsequent infection. The total cost of MRSA screening at ELHT was calculated as a minimum of 184,170 Pounds. This could extrapolate to a national expense of around 16 million pounds in England and Wales in Orthopaedics alone. The MRSA screening program did not meet 4 out of 9 screening criteria of Wilson and Junger. The vast majority of Trauma and Orthopaedic patients are not at risk of MRSA colonisation or infection and therefore should not be screened. MRSA infection is a risk in certain high risk groups which should be screened. The MRSA screening program is ineffective when assessed to WHO standards. The program should be considered to be surveillance of MRSA, not an effective screening program for pathological MRSA infection.