Aims. The modified Radiological Union Scale for Tibia (mRUST) fractures score was developed in order to assess progress to union and define a numerical assessment of fracture healing of metadiaphyseal fractures. This score has been shown to be valuable in predicting radiological union; however, there is no information on the sensitivity, specificity, and accuracy of this index for various cut-off scores. The aim of this study is to evaluate sensitivity, specificity, accuracy, and cut-off points of the mRUST score for the diagnosis of metadiaphyseal fractures healing. Methods. A cohort of 146 distal femur fractures were retrospectively identified at our institution. After excluding AO/OTA type B fractures, nonunions, follow-up less than 12 weeks, and patients aged less than 16 years, 104 sets of radiographs were included for analysis. Anteroposterior and lateral femur radiographs at six weeks, 12 weeks, 24 weeks, and final follow-up were separately scored by three surgeons using the mRUST score. The sensitivity and specificity of mean mRUST score were calculated using clinical and further radiological findings as a gold standard for ultimate fracture healing. A receiver operating characteristic curve was also performed to determine the cut-off points at each time point. Results. The mean mRUST score of ten at 24 weeks revealed a 91.9% sensitivity, 100% specificity, and 92.6% accuracy of predicting ultimate fracture healing. A cut-off point of 13 points revealed 41.9% sensitivity, 100% specificity, and 46.9% accuracy at the same time point. Conclusion. The mRUST score of ten points at 24 weeks can be used as a viable screening method with the highest sensitivity, specificity, and accuracy for healing of metadiaphyseal femur fractures. However, the cut-off point of 13 increases the specificity to 100%, but decreases sensitivity. Furthermore, the mRUST score should not be used at six weeks, as results show an inability to accurately predict eventual fracture healing at this time point. Cite this article: Bone Jt Open 2021;2(10):796–805

Aims. Monocyte-lymphocyte ratio (MLR) or neutrophil-lymphocyte ratio (NLR) are useful for diagnosing periprosthetic joint infection (PJI), but their diagnostic values are unclear for screening fixation-related infection (FRI) in patients for whom conversion total hip arthroplasty (THA) is planned after failed internal fixation for femoral neck fracture. Methods. We retrospectively included 340 patients who underwent conversion THA after internal fixation for femoral neck fracture from January 2008 to September 2020. Those patients constituted two groups: noninfected patients and patients diagnosed with FRI according to the 2013 International Consensus Meeting Criteria. Receiver operating characteristic (ROC) curves were used to determine maximum sensitivity and specificity of these two preoperative ratios. The diagnostic performance of the two ratios combined with preoperative CRP or ESR was also evaluated. Results. The numbers of patients with and without FRI were 19 (5.6%) and 321 (94.4%), respectively. Areas under the ROC curve for diagnosing FRI were 0.763 for MLR, 0.686 for NLR, 0.905 for CRP, and 0.769 for ESR. Based on the Youden index, the optimal predictive cutoffs were 0.25 for MLR and 2.38 for NLR. Sensitivity and specificity were 78.9% and 71.0% for MLR, and 78.9% and 56.4% for NLR, respectively. The combination of CRP with MLR showed a sensitivity of 84.2% and specificity of 94.6%, while the corresponding values for the combination of CRP with NLR were 89.5% and 91.5%, respectively. Conclusion. The presence of preoperative FRI among patients undergoing conversion THA after internal fixation for femoral neck fracture should be determined. The combination of preoperative CRP with NLR is sensitive tool for screening FRI in those patients. Cite this article: Bone Joint J 2021;103-B(9):1534–1540

Aims. The primary aim was to assess the independent influence of coronavirus disease (COVID-19) on 30-day mortality for patients with a hip fracture. The secondary aims were to determine whether: 1) there were clinical predictors of COVID-19 status; and 2) whether social lockdown influenced the incidence and epidemiology of hip fractures. Methods. A national multicentre retrospective study was conducted of all patients presenting to six trauma centres or units with a hip fracture over a 46-day period (23 days pre- and 23 days post-lockdown). Patient demographics, type of residence, place of injury, presentation blood tests, Nottingham Hip Fracture Score, time to surgery, operation, American Society of Anesthesiologists (ASA) grade, anaesthetic, length of stay, COVID-19 status, and 30-day mortality were recorded. Results. Of 317 patients with acute hip fracture, 27 (8.5%) had a positive COVID-19 test. Only seven (26%) had suggestive symptoms on admission. COVID-19-positive patients had a significantly lower 30-day survival compared to those without COVID-19 (64.5%, 95% confidence interval (CI) 45.7 to 83.3 vs 91.7%, 95% CI 88.2 to 94.8; p < 0.001). COVID-19 was independently associated with increased 30-day mortality risk adjusting for: 1) age, sex, type of residence (hazard ratio (HR) 2.93; p = 0.008); 2) Nottingham Hip Fracture Score (HR 3.52; p = 0.001); and 3) ASA (HR 3.45; p = 0.004). Presentation platelet count predicted subsequent COVID-19 status; a value of < 217 × 10. 9. /l was associated with 68% area under the curve (95% CI 58 to 77; p = 0.002) and a sensitivity and specificity of 63%. A similar number of patients presented with hip fracture in the 23 days pre-lockdown (n = 160) and 23 days post-lockdown (n = 157) with no significant (all p ≥ 0.130) difference in patient demographics, residence, place of injury, Nottingham Hip Fracture Score, time to surgery, ASA, or management. Conclusion. COVID-19 was independently associated with an increased 30-day mortality rate for patients with a hip fracture. Notably, most patients with hip fracture and COVID-19 lacked suggestive symptoms at presentation. Platelet count was an indicator of risk of COVID-19 infection. These findings have implications for the management of hip fractures, in particular the need for COVID-19 testing. Cite this article: Bone Joint J 2020;102-B(9):1219–1228

Limb-injury severity scores are designed to assess orthopaedic and vascular injuries. In Gustilo type-IIIA and type-IIIB injuries they have poor sensitivity and specificity to predict salvage or outcome. We have designed a trauma score to grade the severity of injury to the covering tissues, the bones and the functional tissues, grading the three components from one to five. Seven comorbid conditions known to influence the management and prognosis have been given a score of two each. The score was validated in 109 consecutive open injuries of the tibia, 42 type-IIIA and 67 type-IIIB. The total score was used to assess the possibilities of salvage and the outcome was measured by dividing the injuries into four groups according to their scores as follows: group I scored less than 5, group II 6 to 10, group III 11 to 15 and group IV 16 or more. A score of 14 to indicate amputation had the highest sensitivity and specificity. Our trauma score compared favourably with the Mangled Extremity Severity score in sensitivity (98% and 99%), specificity (100% and 17%), positive predictive value (100% and 97.5%) and negative predictive value (70% and 50%), respectively. A receiver-operating characteristic curve constructed for 67 type-IIIB injuries to assess the efficiency of the scores to predict salvage, showed that the area under the curve for this score was better (0.988 (± 0.013 . sem. )) than the Mangled Extremity Severity score (0.938 (± 0.039 . sem. )). All limbs in group IV and one in group III underwent amputation. Of the salvaged limbs, there was a significant difference in the three groups for the requirement of a flap for wound cover, the time to union, the number of surgical procedures required, the total days as an in-patient and the incidence of deep infection (p < 0.001 for all). The individual scores for covering and functional tissues were also found to offer specific guidelines in the management of these complex injuries. The scoring system was found to be simple in application and reliable in prognosis for both limb-salvage and outcome measures in type-IIIA and type-IIIB open injuries of the tibia

Shoulder pain or loss of normal range of motion is a frequent complaint in the outpatient clinic. Of these presentations, rotator cuff injury is a common cause. This can range from mild, transient inflammation of the tendons, to partial tears of tendons, or even full thickness tears. Disruption of the tendons can occur from forceful forward throwing actions undertaken in some sports, for example baseball pitching, more commonly in the UK however, chronic impingement can lead eventually to a tendon tear-usually seen in an older population. Current methods of investigation of such injuries after clinical history and examination, includes plain film radiography, ultrasonography, magnetic resonance imaging and arthrography. We decided to look at how ultrasound can be used in the district general hospital for investigation of such injuries. Aims. To determine the accuracy of ultrasound as an investigative tool for clinically suspected rotator cuff tears. Methods. Seventy-five consecutive ultrasonographic study reports, in patients who subsequently underwent arthroscopic examination, were scrutinised and correlated with surgical findings. From this, sensitivity and specificity of ultrasound at this district general hospital were calculated. In addition, this data was compiled for each of the three Consultant Radiologists in order to assess the operator dependent nature of ultrasound. Results. Of the 74 cases analysed, 43 (58.1%) had full correlation with the arthroscopy findings, 13 (17.6%) had mixed correlation, and 18 cases (24.3%) had no correlation between the ultrasound and arthroscopy report. The sensitivity and specificity of ultrasound at our institution was 0.76 and 0.8 respectively with regards to a tear being detected at ultrasound and then visualised during surgery. Conclusions. There is no current national guidance as to which imaging modality should be first line following clinical examination. Magnetic resonance arthrography, widely thought of as being the gold standard investigation, is not only expensive and possible only in certain centres, but is also invasive, time consuming, and has many relative contraindications. Ultrasound offers a clinical advantage by allowing the radiologist to speak to the patient and assess their range of motion whilst performing the study. This interaction is lost totally in MRI, CT and even MR arthrography. Our study shows that ultrasonography can be quite accurate in identifying a rotator cuff tear. Although it is operator-dependent, ultrasound should be considered more often as a first-line imaging tool for suspected rotator cuff tears as it is relatively inexpensive, quick, and most importantly dynamic

Aims. The aim of this study was to evaluate the diagnostic value of preoperative serum CRP, white blood cell count (WBC), percentage of neutrophils (%N), and neutrophil to lymphocyte ratio (NLR) when using the fracture-related infection (FRI) consensus definition. Methods. A cohort of 106 patients having surgery for suspected septic nonunion after failed fracture fixation were studied. Blood samples were collected preoperatively, and the concentration of serum CRP, WBC, and differential cell count were analyzed. The areas under the curve (AUCs) of diagnostic tests were compared using the z-test. Regression trees were constructed and internally cross-validated to derive a simple diagnostic decision tree. Results. Using the FRI consensus definition, 46 patients (43%) were identified as infected. Sensitivity, specificity, and AUC of CRP were 67% (95% confidence interval (CI) 52% to 80%), 61% (95% CI 47% to 74%), and 0.64 (95% CI 0.54 to 0.74); of WBC count were 17% (95% CI 9% to 31%), 95% (95% CI 86% to 99%), and 0.57 (95% CI 0.50 to 0.62); of %N 13% (95% CI 6% to 26%), 87% (95% CI 76% to 93%), and 0.50 (95% CI 0.43 to 0.56); and of NLR 28% (95% CI 17% to 43%), 80% (95% CI 68% to 88%), and 0.54 (95% CI 0.46 to 0.63), respectively. A better performance of serum CRP was shown in comparison to the leucocyte count (p = 0.006), %N (p < 0.001), and NLR (p = 0.001). A statistically lower serum CRP level was shown in patients with an infection caused by a low virulence microorganism in comparison to high virulence bacteria (p = 0.008). We found that a simple decision tree approach using only low serum neutrophils (< 3.615 × 10. 9. /l) and low CRP (< 2.45 mg/l) may allow better identification of aseptic cases. Conclusion. The evaluated serum inflammatory markers showed limited diagnostic value in the preoperative diagnosis of FRI when using the uniform FRI Consensus Definition. Therefore, they should remain as suggestive criteria in diagnosing FRI. Although CRP showed a higher performance in comparison to the other serum markers, it is insufficiently accurate to diagnose a septic nonunion, especially when caused by low virulence microorganisms. Cite this article: Bone Joint J 2020;102-B(7):904–911

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Though most humeral shaft fractures heal nonoperatively, up to one-third may lead to nonunion with inferior outcomes. The Radiographic Union Score for HUmeral Fractures (RUSHU) was created to identify high-risk patients for nonunion. Our study evaluated the RUSHU’s prognostic performance at six and 12 weeks in discriminating nonunion within a significantly larger cohort than before.

Aims

There is a lack of published evidence relating to the rate of nonunion seen in occult scaphoid fractures, diagnosed only after MRI. This study reports the rate of delayed union and nonunion in a cohort of patients with MRI-detected acute scaphoid fractures.

Aims. To evaluate whether an ultra-low-dose CT protocol can diagnose selected limb fractures as well as conventional CT (C-CT). Patients and Methods. We prospectively studied 40 consecutive patients with a limb fracture in whom a CT scan was indicated. These were scanned using an ultra-low-dose CT Reduced Effective Dose Using Computed Tomography In Orthopaedic Injury (REDUCTION) protocol. Studies from 16 selected cases were compared with 16 C-CT scans matched for age, gender and type of fracture. Studies were assessed for diagnosis and image quality. Descriptive and reliability statistics were calculated. The total effective radiation dose for each scanned site was compared. Results. The mean estimated effective dose (ED) for the REDUCTION protocol was 0.03 milliSieverts (mSv) and 0.43 mSv (p < 0.005) for C-CT. The sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of the REDUCTION protocol to detect fractures were 0.98, 0.89, 0.98 and 0.89 respectively when two occult fractures were excluded. Inter- and intra-observer reliability for diagnosis using the REDUCTION protocol (κ = 0.75, κ = 0.71) were similar to those of C-CT (κ = 0.85, κ = 0.82). Using the REDUCTION protocol, 3D CT reconstructions were equivalent in quality and diagnostic information to those generated by C-CT (κ = 0.87, κ = 0.94). Conclusion. With a near 14-fold reduction in estimated ED compared with C-CT, the REDUCTION protocol reduces the amount of CT radiation substantially without significant diagnostic decay. It produces images that appear to be comparable with those of C-CT for evaluating fractures of the limbs. Cite this article: Bone Joint J 2016;98-B:1668-73

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To investigate if preoperative CT improves detection of unstable trochanteric hip fractures.

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The aim of this study was to investigate the association between additional rehabilitation at the weekend, and in-hospital mortality and complications in patients with hip fracture who underwent surgery.

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The purpose of this study was to develop a convolutional neural network (CNN) for fracture detection, classification, and identification of greater tuberosity displacement ≥ 1 cm, neck-shaft angle (NSA) ≤ 100°, shaft translation, and articular fracture involvement, on plain radiographs.

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

Objectives. Establishing the diagnosis of implant-associated infections is often difficult, because of variable clinical presentations and lack of uniform diagnostic criteria. Sonication of removed orthopedic devices was shown to have superior sensitivity and specificity for infection. We evaluated the value of microcalorimetry as a quick and reliable tool in the diagnosis of infection in sonication fluid from removed implants. Methods. Between 10/2009 and 02/2010 we prospectively included all removed orthopaedic devices at our institution, which were subjected to sonication. Periprosthetic tissue cultures were performed as standard procedure. The removed device was sonicated in Ringer solution (40 kHz, 1 minute) and the resulting fluid was cultured and centrifuged (3000 × g, 10 minutes). The resulting pellet was resuspended in 3 ml tryptic soy broth for isothermal microcalorimetry (sensitivity of 0.25 μW). The detection time until increase of 20 μW was calculated. A 48-channel batch calorimeter (TA Instruments, New Castle, DE, USA) was used to measure the heat flow at 37°C controlled at 0.0001 °C. Results. 39 cases were included (24 males, mean age ± SD was 63 ± 16 years). 29 cases were orthopedic prostheses (14 hip, 11 knee, 1 shoulder and 1 joint spacers) and 10 cases osteosynthetic materials (6 screws, 3 plates, 1 cement-nail). 13 cases (33%) were infected, of which 10 (77%) were positive in sonication culture and 12 (92%) in microcalorimetry. The mean detection time by microcalorimetry was 11.4 h (range, 0.2 h–20.9 h). Examples for microcalorimetric signals can be seen in Fig.1. Conclusions. Microcalorimety of sonication fluid showed superior sensitivity for the diagnosis of infection with detection time of <24 h. This method is a promising diagnostic assay for a rapid and accurate diagnosis of infections associated with orthopedic devices

Introduction. Rapid identification of bacteria from extemporaneous samples would greatly help management of prosthesis joint infection. The aim of the present retrospective study was to evaluate a new molecular assay (GeneXpert MRSA-SA SSTI (Cepheid)) for detecting Staphylococcus aureus (SA) and methicillin resistance directly from bone and joint samples in less an hour (58 minutes). Material et method. Retrospective study using 91 frozen samples (76 patients) of joints (n=24), bone biopsies (n=42) and tissue biopsies (n=25):. -. SA positive samples: n=72 (methicillin susceptible SA (MSSA), n=63; methicillin resistant MRSA, n=9). -. SA positive samples: n=19. The results were compared with routine results (culture in solid and liquid medium, identification and susceptibility test) from each participating lab. Results. The 72 SA positive samples gave:. -. 68 concordant positive results comprising:. . 9 MRSA positive samples,. . 56 MSSA positive samples,. . 3 MSSA positive samples, positive for SA but with inconclusive results for methicillin resistance. -. 4 negative discordant results for MSSA positive samples. The 19 SA negative samples gave:. . 16 concordant negative results. . 3 SASM positive results for negative culture of samples obtained from patients with other MSSA positive deep or superficial samples, suggesting a higher sensitivity for the GeneXpert test than culture in these cases. Sensitivity and specificty for bone and joint samples:. Se=68/72=94.4%. Sp=16/16=100%. Conclusion. The GeneXpert MRSA-SA SSTI assay provides 58-minute detection of MSSA and MRSA directly from bone and joint samples. Sensitivity and specificity were excellent in this preliminary study. This test may enable real-time peroperative diagnosis of Staphylococcus aureus, which could be very useful in the field of revision surgery. Further prospective studies should be done to accurately determine the PPV, NPV, and clinical and pharmaco-economic impact of this test in the setting of prosthesis joint infection

Aim. To evaluate the correlation between the clinical Kirk Watson test and arthroscopic Geissler classification in scapholunate instability. Methods. All patients undergoing wrist arthroscopy between April 2006 and April 2010 were evaluated. Patients were included in the study if they had a Kirk Watson test and a wrist arthroscopy with an assessment of the stability of the scapholunate joint using the Geissler classification. Patients who had a Kirk Watson test performed with subsequent normal scapholunate joint at arthroscopy were included as a control group. Geissler grades 1 and 2 and grades 3 and 4 were grouped for further analysis into low and high grade instability groups respectively. Results. 76 patients were included in the study. 62 had scapholunate pathology and 14 had normal arthroscopic examinations of the stability of the joint. A positive test was found in 30% (3) of patients with grade 1 instability, 29% (4) with grade 2, 60% (12) with grade 3 and 78% (14) with grade 4 instability demonstrated at arthroscopy. The test was positive more commonly in those with grade IV instability compared with others (78% vs. 43%; p=0.015). There was a higher number with a negative test in the low grade instability group (71% vs. 32%; p=0.01) and a higher number with a positive test in the high grade instability group (68% vs. 29%; p=0.006). The test was most sensitive (78%) and most specific (57%) for those classified with Geissler grade IV instability and sensitivity and specificity were also high for those with high grade instability (68% and 66% respectively). Conclusions. The Kirk Watson test is a sensitive and specific test for diagnosis of higher grade instability of the scapholunate joint. We found a positive correlation between increasing scapholunate instability when assessed using the Geissler classification and positivity of the test. This confirms that the Kirk Watson test can be a useful test in the assessment of those with symptomatic instability of the joint and may reflect damage not only to the scapholunate ligament but to the secondary stabilisers of the joint as well

A multicenter retrospective analysis of patients treated for tibial fracture was conducted to develop a score that correlates with fracture healing time and, ultimately, to identify the risk gradient of delayed healing. The clinical records of 93 patients treated for tibial fracture at three orthopaedic centers were evaluated. Patients were considered healed when full weight bearing was allowed and no further controls were scheduled. For the purpose of our analysis, we separated patients healed within or after 180 days. Patient's risk factors known to be associated to delay healing, as well as fracture morphology and orthopaedic treatment were recorded in an electronic Case Report Form (e-CRF). Information available in the literature was used to weight the relative risk (RR) associated to each risk factor; values were combined to calculate a score to be correlated to the fracture healing time: L-ARRCO (Literature-Algoritmo Rischio Ritardo Consolidazione Ossea). Among all information collected in e-CRFs, we identified other risk factors, associated to delayed healing, that were used to calculate a new score: ARRCO. Univariate logistic analysis was used to determine a correlation between the score and healing time. Analysis by receiver operating characteristic (ROC) and calculation of the area under the curve (AUC) were used for sensitivity and specificity. Complete information was available for 53 patients. The mean value of the L-ARRCO score among patients healed within 180 days was 5.78 ± 1.59 and 7.05 ± 2.46 among those healed afterwards, p=0.044. The mean value of the ARRCO score of patients healed within 180 days was 5.92 ± 1.78 and 9.03 ± 2.79 among those healed afterwards, p<0.0001. The ROC curve shows an AUC of 0.62±0.09 for L-ARRCO and an AUC of 0.82±0.07 for ARRCO, (p<0.0001). We have shown that the ARRCO score value is significantly correlated to fracture healing time. The score may be used to identify fractures at risk of delayed healing, thus allowing surgeon's early intervention to stimulate osteogenesis

Introduction. There is a challenge to detect partial tear of the ACL, the number of bundle injured and the proportion of fibers torn. The MRI was shown efficient to individualize the two anteromedial (AM) and posterolateral (PL) bundles of the ACL. The purpose of this study was to assess the ability of the MRI to detect partial tears of the ACL on axial views to display the AM and PL bundles. Materials and methods. This retrospective study included 48 patients (19 partial tears of the ACL, 16 complete rupture of the ACL and 13 normal knee) who underwent both arthroscopy and MRI examinations of the knee. The conventional MRI protocol included one sagittal T1- weighted sequence and 3 proton-density fat sat. The images from MRI were analysis by a radiologist specialized in musculoskeletal imaging who was blinding to the arthroscopic findings. The criteria for the analysis of MRI were divided into primary (those involving the ACL himself) and secondary signs (associated abnormalities). The primary signs included the horizontalisation of the ACL (ACL axis), the global ACL signal intensity and the signal intensity of each AM and PL bundle. The secondary signs included bone bruise, osteochondral impaction, popliteus muscle injury, medial collateral ligament injury and joint effusion. The ACL was classified as normal, partially or totally torn. The rupture of the AM and PL bundle was specified. Results. In our study, MRI was found to have a 75% sensitivity and a 73% specificity for the diagnosis of partial tears of the ACL. The sensitivity to detect AM bundle lesion was 88% but the specificity was 50%. The lack of horizontalisation of the ACL was a very good sign, for partial tears of the ACL, with a sensitivity of 84% and a specificity of 81% (p<0.05). Regarding the secondary signs, there was no significant difference to distinguish partial and complete tear. However, we found that there was a greater probability to find a partial tear of the ACL with the lack of joint effusion, bone bruise and medial collateral ligament injury. Quantifying the proportion of injured fibers was unsuccessful and was found as a failure of the MRI. Conclusions. MRI exhibited lower sensitivity and specificity for partial tear than for complete rupture of the ACL. However 3 important arguments can guide us: the lack of horizontalisation of the ACL, a continuous ACL signal, the display of one of two bundles on the axial view

Aim. The aim was to investigate the value of quantitative histological analysis in the diagnosis of fracture-related infection (FRI). Patients and Methods. The clinical features, microbiology culture results and histological analysis in 156 surgically treated non-unions were used to stratify the likelihood of associated infection. There were 64 confirmed infected non-unions (≥1 confirmatory criteria; pus, sinus and bacterial growth in ≥2 samples), 66 aseptic non-unions (no confirmatory criteria) and 26 possibly infected (pathogen identified from a single specimen and no confirmatory criteria). The histological inflammatory response was assessed by average neutrophil polymorphs (NPs) counts per high power field (HPF) and compared to the established diagnosis. Results. Assuming a cut-off of >5NPs/HPF for positive histological diagnosis, there was 80% sensitivity and 100% specificity (accuracy 90%). Using a cut-off of any NPs/HPF (>0) for negative histological diagnosis there was a sensitivity of 98% and a specificity of 85% (accuracy 92%). Conclusion. Histology can be used in a bimodal fashion as a diagnostic test for FRI. The presence of >5 NPs/HPF has a positive predictive value of 100%, while the complete absence of any NPs is almost always indicative of an aseptic non-union (negative predictive value: 98%)

Introduction. Acetabular labral pathology is now recognized as a more common injury than previously thought. With cost constraints of MRI and invasiveness of MRI arthrogram, physical examination remains essential for diagnosis. Most tests for labral pathology are currently done in the supine position. We have developed the “twist test,” which is done with the patient standing and can evaluate the patient in functional, weight bearing position. The purpose of this study is to describe the twist test and compare its reliability to MRI arthrogram. Material and methods. Between June 2009 and August 2010, the twist test was performed on all patients presenting to our clinic with complaint of hip pain. 371 patients had the twist test performed. Of these, 247 had an MRI arthrogram (MRA) of the affected hip. The twist test results were compared with MRA findings. A labral tear, degeneration, fraying and paralabral cyst were considered as a positive MRA. The twist test is done with the patient facing the examiner, toes pointing forward. The patient bends their knees to 30 degrees and performs a windshield wiper like action with maximal excursion to the left and right. If the patient tolerates this, then the patient first gets on the unaffected leg, again with the knee bent at 30 degrees, and “does the twist” one-legged, with the examiner holding their hands gently for balance. The test is then repeated on the affected hip. A positive test is groin pain on the affected hip, apprehension with performing the test on the affected hip, or gross range of motion deficits on the affected hip compared with the unaffected side. Results. Among 160 patients with positive twist test, 154 patients had positive MRA and 6 had negative MRA. Among 87 patients with negative twist test, 72 had positive MRA and 15 had negative MRA. In comparison with MRA, the sensitivity and specificity of twist test for labral injury were 68.14% and 71.5% respectively. Positive predictive value (precision) of twist test for diagnosis of labral lesion was 96.25% and the accuracy was 68.4%. Conclusions. Physical examination tests for hip pathology are an important screening tool. Current tests include the McCarthy test and the impingement test. We introduce a new test for hip labral pathology, which is done standing. In our study, the twist test had a high positive predictive value (96.25%), so this test can be beneficial for ruling out labral pathology. An added benefit is that this test is quick to perform, so it could be incorporated into a general sports physical screening examination