Aims

Global literature suggests that female surgical trainees have lower rates of independent operating (operative autonomy) than their male counterparts. The objective of this study was to identify any association between gender and lead/independent operating in speciality orthopaedic trainees within the UK national training programme.

Aims

As the world continues to fight successive waves of COVID-19 variants, we have seen worldwide infections surpass 100 million. London, UK, has been severely affected throughout the pandemic, and the resulting impact on the NHS has been profound. The aim of this study is to evaluate the impact of COVID-19 on theatre productivity across London’s four major trauma centres (MTCs), and to assess how the changes to normal protocols and working patterns impacted trauma theatre efficiency.

Currently, the consensus regarding subscapularis tendon repair during a reverse total shoulder arthroplasty (rTSA) is to do so if it is possible. Repair is thought to decrease the risk of dislocation and improve internal rotation but may also increase stiffness and improvement in internal rotation may be of subclinical benefit. Aim is to retrospectively evaluate the outcomes of rTSA, with or without a subscapularis tendon repair. We completed a retrospective review of 51 participants (25 without and 26 with subscapularis repair) who received rTSR by a single-surgeon using a single-implant. Three patient reported outcome measures (PROM) were assessed pre-operatively and post-operative at twelve months, as well as range of movement (ROM) and plain radiographs. Statistical analysis utilized unpaired t tests for parametric variables and Mann-Whitney U test for nonparametric variables. External Rotation ROM pre-operatively was the only variable with a significance difference (p=0.02) with the subscapularis tendon repaired group having a greater range. Pre- and post-operative abduction (p=0.72 & 0.58), forward flexion (p=0.67 & 0.34), ASES (p=0.0.06 & 0.78), Oxford (p=0.0.27 & 0.73) and post-operative external rotation (p=0.17). Greater external rotation ROM pre-operatively may be indicative of the ability to repair the subscapularis tendon intra-operatively. However, repair does not seem to improve clinical outcome at 12 months. There was no difference of the PROMs and AROMs between the subscapularis repaired and not repaired groups for any of the variables at the pre-operative or 12 month post operative with the exception of the external rotation ROM pre-operatively. We can conclude that from PROM or AROM perspective there is no difference if the tendon is repaired or not in a rTSR and indeed the patients without the repair may have improved outcomes at 12 months

Background. Prospective study to compare patient reported outcome measures (PROM) for sacroiliac joint (SIJ) fusion using HA-coated screw (HACS) vs triangular titanium dowel (TTD). First study of its kind in English literature. Methods. 40 patients underwent percutaneous SIJ stabilisation using HACS and TTD was used in 70 patients. Patients were followed up closely and outcome scores were collected prospectively. PROMs were collected preoperatively and 12 months after surgery. Short Form (SF)-36, Oswestry Disability Index, EuroQol-5D-5L and Majeed Pelvic Scores were collected. Shapiro-wilk test was used to determine normality of data. Mann-whitney U test was used to compared non-parametric data and Independent sample T test for parametric data. Results. 33 patients in HACS group and 61 in TTD group completed follow-up. There was no significant difference in all preoperative PROMs in both groups hence the data was considered comparable. All postoperative PROMs were significantly higher in the TTD group. In the HACS group, 21 patients (63%) had lysis around the screw and a sub-group analysis showed that improvement in PROMs was significantly less in patients with lysis around the screw. 4 patients with lysis around the screw were offered revision due to ongoing pain. Revision was successful in only 1 patient. In TTD group only 5 patients (8.2 %) patients had radiological evidence of lysis. Relative risk of developing lysis was 6.7 times higher in HACS group. Conclusion. Percutaneous SIJ fixation procedure has been shown to have good clinical outcomes and TTD leads to significantly better patient reported outcomes compared to HACS. There is a 6.7 time higher risk of lysis with use of HACS and lysis is a risk factor for poor outcomes

Aim. Periprosthetic joint infection (PJI) is a complication of total joint arthroplasty that typically requires revision surgery for treatment. Systemic antibiotics are usually held prior to surgery to improve yield of intraoperative cultures. However, recent studies suggest that preoperative aspirations have a high concordance with intraoperative cultures, which may allow surgeons to initiate antibiotic treatment earlier. The purpose of the study was to investigate the effect of Pre-surgical systemic antibiotic therapy on the bacterial burden within the periprosthetic space and systemic immune reaction. Method. PJI was induced with MSSA (Xen36) S. aureus in the right knee of 16-week old, female, C57BL6 mice using a previously validated murine model. Mice were randomized to three groups (n=8, each): control; Vanc, receiving systemic vancomycin (110mg/kg, SQ, twice daily); or VancRif receiving vancomycin same as in Vanc group, plus rifampin (12mg/kg dose, IV, once daily). Following 2 weeks of treatment, mice were euthanized and periprosthetic bone, soft tissue and the implant were harvested. Bacterial burden, colony forming units (CFUs), was quantified in soft tissue, tibial bone, and on the implant. Specifically, tissues were homogenized and serially plated for CFUs, while the implant was sonicated and then plated for CFUs. The host immune response was analysed through weighing inguinal and iliac lymph nodes and through measuring serum amyloid A (SAA). Non-parametric pairwise group comparisons of the three outcome measures were performed using a Mann-Whitney U test. Results. VancRif, the combined treatment significantly reduced bacterial burden in the periprosthetic soft tissue, bone, and implant compared to control (p<0.001) and Vanc alone (p<0.001). While not significant, Vanc alone did reduce bacterial load as compared to control. The ipsilateral weight of the iliac lymph nodes was significantly reduced in Vanc and VancRif mice compared to controls (p<0.001), was well as in VancRif versus Vanc alone (p<0.001). Interestingly, SAA levels did not significantly differ among all groups. During tissue harvesting, minimal purulence was observed in antibiotic treatment groups, unlike controls. Conclusions. Treating active PJI with vancomycin alone decreases periprosthetic bacterial loads and reduces the local immunological response. This effect is significantly enhanced with the combined rifampin use. These findings could suggest that when culture positive PJI is diagnosed, pre-surgical treatment with antibiotics may decrease immunosuppression and soft tissue infiltration, leading to a better chance of infection cure with subsequent surgical debridement. Histological investigations and repeat experiments involving subsequent surgical treatment are underway. Acknowledgements. Funding comes from internal institutional grants

Aims. The purpose of our study was to determine which groups of orthopaedic providers favour virtual care, and analyze overall orthopaedic provider perceptions of virtual care. We hypothesize that providers with less clinical experience will favour virtual care, and that orthopaedic providers overall will show increased preference for virtual care during the COVID-19 pandemic and decreased preference during non-pandemic circumstances. Methods. An orthopaedic research consortium at an academic medical system developed a survey examining provider perspectives regarding orthopaedic virtual care. Survey items were scored on a 1 to 5 Likert scale (1 = “strongly disagree”, 5 = “strongly agree”) and compared using nonparametric Mann-Whitney U test. Results. Providers with less experience were more likely to recommend virtual care for follow-up visits (3.61 on the Likert scale (SD 0.95) vs 2.90 (SD 1.23); p = 0.006) and feel that virtual care was essential to patient wellbeing (3.98 (SD 0.95) vs 3.00 (SD 1.16); p < 0.001) during the pandemic. Less experienced providers also viewed virtual visits as providing a similar level of care as in-person visits (2.41 (SD 1.02) vs 1.76 (SD 0.87); p = 0.006) and more time-efficient than in-person visits (3.07 (SD 1.19) vs 2.34 (SD 1.14); p = 0.012) in non-pandemic circumstances. During the pandemic, most providers viewed virtual care as effective in providing essential care (83.6%, n = 51) and wanted to schedule patients for virtual care follow-up (82.2%, n = 50); only 10.9% (n = 8) of providers preferred virtual visits in non-pandemic circumstances. Conclusion. Orthopaedic providers with less clinical experience seem to favourably view virtual care both during the pandemic and under non-pandemic circumstances. Providers in general appear to view virtual care positively during the pandemic but are less accommodating towards it in non-pandemic circumstances. Cite this article: Bone Jt Open 2021;2(6):405–410

Abstract. Background. Prospective study to compare patient reported outcome measures (PROM) for sacroiliac joint (SIJ) fusion using HA-coated screw (HACS) vs triangular titanium dowel (TTD). First study of its kind in English literature. Methods. 40 patients underwent SIJ stabilisation using HACS and TTD was used in 70 patients at CAVUHB, Cardiff. PROMs were collected prospectively before surgery and 12 months post-op. Short Form (SF)-36, Oswestry Disability Index, EuroQol-5D-5L and Majeed Pelvic Scores were collected. Shapiro-wilk test was used to determine normality of data. Mann-whitney U test was used to compared non-parametric data and Independent sample T test for parametric data. Results. 33 patients in HACS group and 61 in TTD group completed follow-up. There was no significant difference in all preoperative PROMs in both groups hence the data was considered comparable. All postoperative PROMs were significantly higher in TTD group. In HACS group, 21 patients (63%) had lysis around screw and sub-group analysis showed that PROMs were lower in patients with lysi. 4 patients with lysis around screw were offered revision due to ongoing pain. Revision was successful in only 1 patient. In TTD group only 5 patients (8.2 %) patients had radiological evidence of lysis. Relative risk of developing lysis was 6.7 times higher in HACS group. Conclusion. Percutaneous SIJ fixation procedure has good clinical outcomes and TTD leads to significantly better patient reported outcomes compared to HACS. There is a 6.7 time higher risk of lysis with use of HACS and lysis is a risk factor for poor outcomes

Surgical treatment options for Femoroacetabular impingement (FAI) includes both surgical dislocation and hip arthroscopy techniques. The primary aim of this study was to evaluate and compare the survivorship of arthroscopies (scope) and surgical dislocations (SD) at minimum 5-year follow-up. The secondary aim was to describe differences in functional outcomes between the 2 groups. This was a retrospective, single surgeon, consecutive, case-series from a large tertiary care centre. We evaluated all surgeries that were performed between 2005 and 2011. Our institutional database was queried for any patient undergoing surgery for FAI (pincer (n=23), cam (n=306), or mixed (n=103) types). Patients with childhood pathologies i.e. Legg Calve Perthes and slipped capital femoral epiphysis were excluded. This resulted in 221 hips (169 males, 52 females) who underwent either SD (94, 42.5%) or scope (127, 57.5%). A manual chart review was completed to identify patients who sustained a complication, underwent revision surgery or progressed to a total hip arthroplasty (THA). In addition, we reviewed prospectively collected patient reported outcome measure (PROMs) using (SF12, HOOS, and UCLA). Survivorship outcome was described for the whole cohort and compared between the 2 surgical groups. PROMs between groups were compared using The Mann-Whitney U test and the survival between groups was assessed using the Kaplan-Meier Analysis and the Log-Rank Mantel Cox test. All analyses were performed in SPSS (IBM, v. 26.0). The cohort included 110 SDs and 320 arthroscopies. The mean age of the whole cohort was 34±10; patients in the SD group (32±9) were younger compared to the arthroscopy group (39±10) (p<0.0001). There were 16 post-operative complications (similar between groups) and 77 re-operations (more common in the SD group (n=49) due to symptomatic metal work (n=34)). The overall 10-year survival was 91±3%. Survivorship was superior in the arthroscopy group at both 5- (96% (95%CI: 93 – 100)) and 8- years 94% (95%CI: 90 – 99%) compared to the SD Group (5-yr: 90% (95%CI: 83 – 98); 8-yr: 84% (95%CI:75 – 93)) (p=0.003) (Figure 1). On average HOOS improved from 54±19 to 68±22 and WOMAC from 65±22 to 75±22. The improvement in PROMs were similar between the 2 groups. We report very good long-term joint preservation for the treatment of FAI, which is similar to those reported in hip dysplasia. In addition, we report satisfactory improvement in function following such treatment. The differences reported in joint survival likely reflect selection biases from the treating surgeon; more complex cases and those associated with more complex anatomy were more likely to have been offered a SD in order to address the pathology with greater ease and hence the inferior joint preservation identified in this group. For any figures or tables, please contact the authors directly

The primary aim of this study was to identify the rate of osteoarthritis in scaphoid fracture non-union. We also aimed to investigate whether the incidence of osteoarthritis correlates with the duration of non-union(interval), and to identify the variables that influence the outcome. We retrospectively reviewed 273 scaphoid fracture non-union presented between 2007 and 2016. Data included patient demographics, interval, fracture morphology, grade of osteoarthritis (Kellgren-Lawrence) and scaphoid non-union advanced collapse (SNAC), and overall health-related quality of life. Patients were divided into two groups (SNAC and Non-SNAC). Group differences were analysed using Mann-Whitney U test and association with Pearson's correlations. A two-sided p-value of <0.05 was considered significant. The scaphoid fracture non-union were confirmed on CT scans (n=243) and plain radiographs (n=35). The subjects were 32 females and 260 males with the mean age of 33.8 years (SD, 13.2). The average interval was 3.1 years (range, 0–45 years). Osteoarthritis occurred in 58% (n=161) of non-unions, and 42% (n=117) had no osteoarthritis. In overall, 38.5% (n=107) had SNAC-1, 9% (n=25) with SNAC-2, and 10.4% (n=29) presented with SNAC-3. The mean interval in the non-SNAC group was 1.2 years, and in SNAC 1,2, and 3 were 2.6, 6.8, and 11.1 years, respectively. The average summary index in SNAC and non- SNAC groups was 0.803 and 0.819, respectively. Our results also showed a significant correlation between advanced osteoarthritis and proximal fracture non-unions(P<0.05). We concluded that there is no clear correlation between the interval and the progression of osteoarthritis. SNAC was more likely to occur in fractures aged 2 years or older

Osteomyelitis and septic arthritis are common pathologies in young children. Because of their skeletal immaturity, children are particularly vulnerable to orthopaedic complications, including limb-length discrepancies, angular deformities, chondrolysis, etc. The primary objective of this study was to review the clinical follow up and outcomes of paediatric patients diagnosed with osteoarticular infections. The secondary purpose was to look for significant differences in the clinical characteristics between the one with and without complications. Patients' medical charts, hospitalised between 2010 and 2016, were retrospectively reviewed. The inclusion criteria were: patients (1) aged of less than 10 years old (2) treated and followed for osteomyelitis of long bones of upper and lower extremities and/or septic arthritis (3) with at least one year of radiological follow up. The exclusion criterion was: (1) any concomitant chronic diseases. The information collected included demographic and clinical data. A late sequela was defined as a limb-length discrepancy superior to 5 mm or an abnormal articular angulation of more than 5°, or a symptomatic chondropathy. Patients were separated in two groups: with and without complications. Chi-square tests were used for categorical variables and Mann-Whitney U tests for continuous data in order to establish significant differences between both groups. Of the 401 patients with osteomyelitis and/or septic arthritis treated in our tertiary paediatric hospital over 7 years, 50 met the inclusion criteria. There were 24 girls and 26 boys. The etiological agent was identified in 56% of the cases. Staphylococcus aureus was the predominant causal pathogen (50%), followed by Kingella kingae (19.2%). The mean follow up was 780 days. Six out of 50 (12%) patients had physeal or chondrolytic complications at the latest follow-up. The only significant difference between the 2 groups was the delay between onset of symptoms and initiation of antibiotic therapy (P = 0.039). Only 12.5% of the patients were followed up at least one year. In the population of 50 skeletally immature patients without comorbidities, 12% had a sequela. The delay in initiating antibiotic treatment was significantly longer in the group with the presence of sequelae. The results of this study reveal that there were low rates of outpatient follow-up reaching more than a year after an osteoarticular infection, thus raising the question about the importance of a follow up after such a diagnosis. Twelve percent of the patients had a growth or chondrolysis complication and this might be related to the delay before initiating antibiotic treatment

Short scarf osteotomy (SSO) retains the versatility of standard scarf in treating moderate and severe hallux valgus deformity with the added benefit of less invasiveness translated into less soft-tissue stripping, reduced exposure, less metalwork, less operative time and reduced cost. We present our medium-term clinical, radiographic and patient satisfaction results. All patients who underwent SSO between January 2015 and December 2017 were eligible (98). Exclusion criteria were: follow up less than a year, additional 1st ray procedures, inflammatory arthropathy, infection, peripheral vascular disease and hallux rigidus. Eighty-four patients (94 feet) were included: 80 females / 4 males with average age of 51-year-old (24–81). Minimum follow up was 12 months (12–28). Weight-bearing x-rays and AOFAS score were compared pre- and postoperatively. Non-parametric Mann-Whitney U test assessed statistical significance of our results. Hallux valgus angle (HVA) improved from preoperative mean of 30.8° (17.4°–46.8°) to 12° (4°–30°) postoperatively (p=0.0001). Intermetatarsal angle (IMA) improved from preoperative mean of 15.1° (10.3°–21.1°) to 7.1° (4°–15.1°) postoperatively (p=0.0001). Average sesamoid coverage according to Reynold's tibial sesamoid position improved from average grade 2.18 (1–3) to 0.57 (0–2) (p=0.0001). Average AOFAS score improved from 51.26 (32–88) to 91.1 (72–100) (p=0.0001). Ninety percent of patients were satisfied and 83% wound recommend the surgery. No troughing phenomenon or fractures. Four overcorrections were found 3 of which did not require surgery. One recurrence at 18 months was treated with standard scarf. We believe that this technique offers a safer, quicker and equally versatile way of dealing with Hallux Valgus

Background. The decision to resurface the patella during total knee arthroplasty remains controversial. Aim of our study was to evaluate the functional difference between patients undergoing medial rotation knee (MRK) replacement with and without patellar resurfacing at our hospital. Methods. We did a retrospective analysis of patients undergoing MRK total knee replacement (Matortho) at our hospital between 2008 and 2017 performed by 2 surgeons. Patients were recalled for a clinical review from Oct 2017 for recording of Oxford knee, Baldini and Ferrel scores. Mann-Whitney U test was used for non-parametric data (SPSS v24). Results. Of the 104(49 males) patients, 62 had patellar resurfacing. Age and sex distribution was similar in both groups. The mean follow up period was 74.45 months in non- resurfaced group and 54.93 months in resurfaced group. The Median (Range) pre-operative Oxford knee scores were similar in both groups − 15(4–42) in non-resurfaced group and 14(1–44) in resurfaced group. The median OKS at follow-up were 36(12–47) in non-resurfaced group and 37(9–48) in resurfaced group. The Patellar scores were slightly better in the resurfaced group – Baldini score median (range) (90 (25–100) in non resurfaced v/s 100(30–100) in resurfaced), Ferrel score (median (range) 25(12–30) in non-resurfaced v/s 28(10–30) in resurfaced, p 0.042). The patellofemoral component of the OKS (Q5 + Q7 + Q12) median (range) showed an improvement from 3(1–11) to 6.5 (3–11) in non-resurfaced group and from 3(0–12) to 8 (2–12) (p 0.039) in resurfaced group. Conclusion. Although the overall functional knee scores in non-resurfaced and resurfaced groups were same, we found a statistically significant difference in Ferrel score and in the patellofemoral component of OKS between the 2 groups of MRK knee replacement suggesting specific benefits of patellar resurfacing

Introduction. Acetabular dysplasia cause hip joint osteoarthritis(OA) by change hip mechanism. However, to our best knowledge, no studies have been published using prospectively collected data from asymptomatic young age volunteers, precise radiographic method. The purpose of this study is to evaluate the prevalence of hip dysplasia in asymptomatic Korean population as one of the most important risk factor of hip OA. Materials & Methods. From December 2014 to March 2015, we investigated prospectively collected retrospectively reviewed data of 200 asymptomatic volunteers 400 hips in age between 18 and 50 years recruited from our institution. Pelvic radiographs were taken and all radiographs were reviewed by 2 experienced orthopedic surgeons. Lateral center-edge angle(LCEA), Sharp angle, Tonnis angle and acetabular width-depth ratio were measured. We analyzed the statistical differences of these values between sex by Mann-Whitney U test and independent t-test. Pearson's correlation coefficient was used to measure the relationship between dysplasia parameters. Results. On the Pelvic AP view, 60 of the 400 hips (15%) were dysplastic hip as LCEA <20°. In 146 male hips, 17 hips (11.6%) were LCEA <20°. In 254 female hips, 43 hips(16.9%) were LCEA <20°. There was no strong correlation of LCEA with other measurements. Conclusion. There are large number of asymptomatic dysplastic hips in Asian population compared previously investigated

Introduction. The global rapid growth of the aging population has some likelihood to create a serious crisis on health-care and economy at an unprecedented pace. To extend Healthy Life Expectancy (HALE) in a number of countries, it is desired more than ever to investigate characteristic and prognosis of numerous diseases. This enlightenment and recent studies on patient-reported outcome measures (PROMs) will drive the increasing interest in the quality of life among the world. The demand for primary THAs by 2030 would rise up to 174% in USA. It is expected that the number of the elderly will surge significantly in the future, thus more septuagenarian and octogenarian are undergoing THA. Moreover, HALE of Japanese female near the age of 75 years, followed to Singapore, is still increasing. Therefore, concerns exist about the PROMs of performing THA in this age-group worldwide. Nevertheless almost the well-established procedure, little agreement has been reached to the elderly. We aimed to clarify the mid-term PROMs after THA over 75-year old. Methods. Between 2005 and 2013, we performed 720 consecutive primary cemented THAs through a direct lateral approach. Of these, 503 female patients (655 hips) underwent THA for treatment of osteoarthritis, with a minimum follow-up of 5 years, were retrospectively enrolled into the study. We excluded 191 patients (252 hips) aged less than 65-year at the time of surgery and 58 patients (60) because of post-traumatic arthritis or previous surgery (37), or lack of data (23). Thus, 343 hips remained eligible for our study, contributed by 254 patients. We investigated Quality-adjusted life year (QALY), EuroQol 5-Dimension 5-Level scale (EQ-5D) and the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ, which was a disease-specific and self-administered questionnaire, reflecting the specificity of the Japanese cultural lifestyle) in patients aged 75 years or older (154 hips, Group-E) compared with those aged 65 to 74 years (189 hips, Group-C) retrospectively. We evaluated the association between patients aged 75 years or older and the following potential risk factors, using logistic regression analysis: age, number of vertebral fractures (VFs), American Society of Anesthesiologists physical status (ASA-PS) and Charlson Comorbidity Index (CCI). A p value of < 0.05 was considered significant for the Mann-Whitney U test. Results. At a mean follow-up duration of 7.2 years, QALY, EQ-5D and JHEQ for the domain of patient satisfaction were significantly greater for Group-E than Group-C; however, there were no significant differences in JHEQ for pain, movement and mental-health between groups. On multivariate analysis, the age (odds ratio [OR] 2.48, p < .01 for EQ-5D; OR .32, p < .01 for JHEQ satisfaction), VFs (OR 1.63, p < .01 for satisfaction) and ASA-PS (OR .64, p = .31 for EQ-5D) were independent predictive risk factors for patients aged 75-year or older. Conclusions. Based on mid-term follow-up of PROMs study, we suggest that cemented THA can lead to the extension of HALE towards the super aged society and our results can be applied to a systematic analysis for the Global Burden of Disease Study related frailty

Aims. Accurate and precise acetabular reaming is a requirement for the press-fit stability of cementless acetabular hip replacement components. The accuracy of reaming depends on the reamer, the reaming technique and the bone quality. Conventional reamers wear with use resulting in inaccurate reaming diameters, whilst the theoretical beneficial effect of ‘whirlwind’ reaming over straight reaming has not previously been documented. Our aim was to compare the accuracy and precision of single use additively-manufactured reamers with new conventional reamers and to compare the effect of different acetabular reaming techniques. Materials and Methods. Forty composite bone models, half high-density and half low-density, were reamed with a new 61 mm conventional acetabular reamer using either straight or ‘whirlwind’ reaming techniques. This was repeated with a 61 mm single use additively-manufactured reamer. Reamed cavities were scanned using a 3D laser scanner with mean diameters of reamed cavities compared using the Mann-Whitney U test to determine any statistically significant differences between groups (p<0.05) [Fig. 1). Results. Reaming errors were significantly higher in low-density bone compared to high-density bone for both reamer types and reaming techniques tested (61.9 mm (SD 0.7) vs 61.4 mm (SD 0.4), respectively; p=0.0045). Whirlwind reaming was significantly more accurate and precise than straight reaming using both conventional (61.3 mm (SD 0.1) vs 62.3 mm (SD 0.4), respectively; p<0.0001) and single use reamers (61.1 mm (SD 0.3) vs 61.7 mm (SD 0.7), respectively; p=0.0058) [Fig. 2]. The novel single use reamer was significantly more accurate than the unused conventional reamer, using both the straight (61.7 mm (SD 0.7) vs 62.4 mm (SD 0.4), respectively; p=0.0011) and whirlwind techniques (61.2 mm (SD 0.3) vs 61.3 mm (SD 0.1), respectively; p=0.0002) [Fig. 3]. Conclusion. This is the first study to our knowledge that has assessed acetabular reaming technique in both low and high density saw bones. Improved reaming accuracy and precision was seen in both devices tested when using the ‘whirlwind’ technique in both high-density and low-density bone models when compared to a straight reaming technique. The single use device assessed reamed a cavity size closer to its stated size (61mm) compared to conventional reamers. Based on this study we suggest using a careful “whirlwind” technique when performing acetabular reaming, and for the surgeon to pay particular attention when performing joint replacement in patients with reduced bone quality as there is likely to be more variability in acetabular reaming accuracy in these patients

Introduction. In the last couple of years, several synovial biomarkers have been introduced in the diagnostic algorithm for a prosthetic joint infection (PJI). Alpha defensin-1 proved to be one of the most promising, with a high sensitivity and specificity. However, a major disadvantage of this biomarker is the high costs. Calprotectin is a protein that is present in the cytoplasm of neutrophils, and is released upon neutrophil activation. Its value has been established for decades as a (fecal) marker for inflammatory bowel disease. Aim. To determine the efficacy of synovial calprotectin in the diagnosis of a prosthetic joint infection. Methods. We prospectively collected synovial fluid (from hip, knee and shoulder) from patients with a proven PJI (n=15) and from patients that underwent a revision surgery without signs of a PJI (n=19). Patients with an active rheumatoid arthritis and/or gout were excluded from the study. Synovial fluid was centrifuged and the supernatant was used to measure calprotectin, by using a rapid, point of care test. This test was validated for synovial fluid analysis of calprotectin using an ELISA. A Mann-Whitney U test was used to calculate the difference between both patient groups. Results. The median calprotectin level was 899 mg/L (range 28–2120) for PJI versus 22 mg/L (range 0–202) for controls (p < 0.0001). With a cut-off value of 50 mg/L, synovial calprotectin has a high sensitivity of 93%, and a specificity of 84%. The positive and negative predictive values are 82% and 94%, respectively. Conclusions. Synovial calprotectin is a potentially valuable biomarker in the diagnosis of a PJI. With a point of care test, a rapid quantative diagnosis can be made within the operating room (results are obtained within 20 minutes), and could help in the decision making process to re-implant a prosthesis in a one stage procedure. In comparison to the currently available test (to measure alpha defensin-1), the measurement of calprotectin test is much cheaper (500 euro versus 20 euro per sample) and easily to implement in hospitals where this test is already available. Its diagnostic efficacy for exclusively low-grade PJI should be further elaborated

Instability after total hip arthroplasty is the most common indication for revision arthroplasty and can be difficult to treat. The purpose of this study is to evaluate the outcomes associated with the use of a constrained acetabular component as a treatment for instability after hip arthroplasty. We reviewed the clinical and radiographic outcomes of 149 arthroplasties, that had been performed with use of a single design of constrained acetabular component between 2007 and 2012 at a single institution. Patient demographics and case specific data were collected The Mann-Whitney U test was used to assess continuous variables. Categorical variables were examined using the Chi-square test and Fisher's exact test when appropriate. Survival probability was calculated using the Kaplan-Meier method. The mean age at time of index surgery was 70 years, 65% were female, and mean BMI was 26.3. The average number of previous surgeries was 3.6. The constrained liner was cemented into a well-fixed cup in 40 hips (20%). In eighty-two (55%) hips the constrained component was implanted for the treatment of recurrent instability, and in sixty-seven (45%) hips it was implanted because the hips demonstrate instability during revision surgery. At an average duration of follow-up of 4.2 (2–7) years the overall revision rate was 10.6 % The constrained acetabular device eliminated or prevented hip instability in all patients except five; 3.3% had a new dislocation and six (4.0%) had failure of the retentive ring. Three revisions (2%) were performed for deep infection, and 2 (1.3%) for acetabular component loosening. Radiographic analysis revealed a non-progressive radiolucent line around the cup in 19 hips (12.7%). When stratified by patient age, survivorship for patients less than 65 years of age versus those greater than 65 years was similar. This study correlates with results of other papers in the literature looking at outcome of constrained tripolar type sockets. The focal constraint socket with a metal ring type design has a much greater failure rate (9–29%). Constrained liners remain an excellent option for hip instability in early to mid- term follow up

Introduction. The original Charnley-type negative pressure body exhaust suit reduced infection rates in randomized trials of total joint arthroplasty decades ago. Modern positive pressure surgical helmet systems (SHS) have not shown similar benefit, and several recent studies have shown a trend towards increased wound contamination and infection with SHS use. The gown glove interface may be one source of particle contamination. Objectives. The purpose of this study was to compare particle contamination at the gown glove interface in several modern SHS vs. a conventional gown. Methods. A 0.5 micron fluorescent powder was evenly applied to both hands to the level of the wrist flexion crease. After gowning in the normal fashion, the acting surgeon performed a standardized twenty minute simulated total joint replacement. The amount of gown contamination at the gown glove interface was then measured by three observers under ultraviolet light using a standardized grading scale; from 0 (no contamination) to 4 (gross contamination). Using Minitab 15, the Mann-Whitney U test was performed to compare gowns and an ordinal logistic regression analysis was performed to identify variables associated with levels of contamination. Results. All gown-glove interfaces showed some contamination. There was no difference among any of the gowns except for gown 2, which showed significantly more contamination when compared directly to each of the other four gowns (p<0.001 in each case) (Figure 1). The ordinal logistic regression analysis showed that gown type (p 0.10) was more significantly associated with contamination levels than were the other variables of observer (p 0.70), location of contamination (p 0.56), or trial order (p 0.5). Conclusions. Particle contamination occurs at the gown glove interface in most commonly used surgical helmet systems and was significantly increased in the gown with stiffer material that may be less apt to make a seal with the glove

D-dimer is one of the useful laboratory tests to evaluate the incidence of venous thromboembolism (VTE) after the total knee arthroplasty (TKA). The most recent guideline for the prophylaxis of VTE points out the surgical procedure itself is a major risk factor for developing VTE. Only a few literatures discuss the relationship of surgical procedures and the risk of venous thromboembolism. We therefore prospectively compare the difference of the perioperative plasma D-dimer levels between the patients undergoing navigation and convention TKA. Two hundred consecutive total knee arthroplasties were performed between September 2011 and March 2013. The patients were randomised according to their registration to the orthopaedic clinic. Ninety-six patients (100 knees) underwent a navigation-assisted TKA and ninety-four patients (100 knees) had a conventional TKA. No intramedullary violation was done in the navigation-assisted TKA, while the intramedullary femoral guiding was adapted in the conventional group. Pre-operative and post-operation day 1 plasma D-dimer levels were recorded and evaluated using Mann-Whitney U test. There was no difference in the demographic data and pre-operative D-dimer between the two groups (p=0.443). Significantly lower D-dimer levels on the post-operative day 1 were noted in the navigation group, when compared with the conventional group. (6.0 ± 4.4 mg/L vs 11.3 ± 9.6 mg/L, p = 0.000). We demonstrated that lower D-dimer level is developed after the navigation-assisted TKA than the conventional one. Less incidence of VTE is expected and the finding may help to explain the fact that less systemic emboli in the navigation assisted TKA

Eligible patients were randomly allocated to PMI or standard intramedullary jigs. Smith and Nephew's patient specific cutting blocks (Visionaire) were used for PMI. Postoperative component positioning was investigated using the ‘Perth CT protocol’. Deviation of more than 3° from the recommended position was regarded as an outlier. Exact Mann-Whitney U test was used to compare component positioning and difference in proportion of outliers was calculated using Chi Squared analysis. Fifty-five knees were enrolled in the standard instrumentation group and fifty-two knees in the PMI group. Coronal femoral alignment was 0.7 ± 1.9° (standard) vs 0.5 ± 1.6° (PMI) (P=0.33). Outliers 9.4% vs 7.4% (P=0.71). Coronal tibial alignment was 0.4 ± 1.5° (standard) vs 0.6 ± 1.4° (PMI) (P=0.56). Outliers 1.9% vs 1.9% (P=0.99). Sagittal femoral alignment was 0.6 ± 1.5° (standard) vs 1.3 ± 1.9° (PMI) (P=0.07). Outliers 3.8% vs 13.2% (P=0.09). Tibial slope was 1.7 ± 1.9 ° (standard) vs 1.8 ± 2.7° (PMI) (P=0.88). Outliers 13.2% vs 24.1% (P=0.15). External rotation of femoral component was 0.6 ± 1.4° (standard) vs 0.2 ± 1.8° (PMI) (P=0.14). Outliers: 3.8% vs 5.6% (P=0.66). Compared to standard intramedullary jigs, patient matched instrumentation does not improve component positioning or reduce alignment outliers