Effects of temperature and storage time on the motility, viability, DNA integrity and apoptosis of processed human spermatozoa.

The aim of this study was to evaluate motility, viability, DNA integrity and apoptosis of spermatozoa when washed semen samples were kept for up to 12 days at 4-6°C and 25°C. In this experimental study, 26 normozoospermic semen samples were washed twice in Modified Ham's F10 and resuspended in IVF fertilisation medium. Half of the specimens were stored at 4-6°C, and the other half was kept at 25°C for 12 days. The proportions of viable, motile, spermatozoa with double-stranded DNA and apoptotic spermatozoa were examined during storage time. Apoptosis was measured using annexin V-PI staining followed by flow cytometry. Results showed that sperm motility and viability decreased during 12 days of sample storage (p < .001). There was no significant difference between the two temperatures in terms of motility and viability for up to 2 days (p < .05). The percentage of spermatozoa with double-stranded DNA remained unchanged during the 12 days of storage at both temperatures (p > .05). Although there was no difference between the two temperatures in terms of motility, viability and apoptosis during the first two days of storage, storage of spermatozoa at 4-6°C is better than storage for a longer period than storage at 25°C. Sperm DNA resisted against denaturation during storage.

Can an Augmented Reality Headset Improve Accuracy of Acetabular Cup Orientation in Simulated THA? A Randomized Trial.

BACKGROUND: Accurate implant orientation reduces wear and increases stability in arthroplasty but is a technically demanding skill. Augmented reality (AR) headsets overlay digital information on top of the real world. We have developed an enhanced AR headset capable of tracking bony anatomy in relation to an implant, but it has not yet been assessed for its suitability as a training tool for implant orientation. QUESTIONS/PURPOSES: (1) In the setting of simulated THA performed by novices, does an AR headset improve the accuracy of acetabular component positioning compared with hands-on training by an expert surgeon? (2) What are trainees' perceptions of the AR headset in terms of realism of the task, acceptability of the technology, and its potential role for surgical training? METHODS: Twenty-four study participants (medical students in their final year of school, who were applying to surgery residency programs, and who had no prior arthroplasty experience) participated in a randomized simulation trial using an AR headset and a simulated THA. Participants were randomized to two groups completing four once-weekly sessions of baseline assessment, training, and reassessment. One group trained using AR (with live holographic orientation feedback) and the other received one-on-one training from a hip arthroplasty surgeon. Demographics and baseline performance in orienting an acetabular implant to six patient-specific values on the phantom pelvis were collected before training and were comparable. The orientation error in degrees between the planned and achieved orientations was measured and was not different between groups with the numbers available (surgeon group mean error ± SD 16° ± 7° versus AR 14° ± 7°; p = 0.22). Participants trained by AR also completed a validated posttraining questionnaire evaluating their experiences. RESULTS: During the four training sessions, participants using AR-guidance had smaller mean (± SD) errors in orientation than those receiving guidance from the surgeon: 1° ± 1° versus AR 6° ± 4°, p < 0.001. In the fourth session's assessment, participants in both groups had improved (surgeon group mean improvement 6°, 95% CI, 4-8°; p < 0.001 versus AR group 9°, 95% CI 7-10°; p < 0.001). There was no difference between participants in the surgeon-trained and AR-trained group: mean difference 1.2°, 95% CI, -1.8 to 4.2°; p = 0.281. In posttraining evaluation, 11 of 12 participants would use the AR platform as a training tool for developing visuospatial skills and 10 of 12 for procedure-specific rehearsals. Most participants (11 of 12) stated that a combination of an expert trainer for learning and AR for unsupervised training would be preferred. CONCLUSIONS: A novel head-mounted AR platform tracked an implant in relation to bony anatomy to a clinically relevant level of accuracy during simulated THA. Learners were equally accurate, whether trained by AR or a surgeon. The platform enabled the use of real instruments and gave live feedback; AR was thus considered a feasible and valuable training tool as an adjunct to expert guidance in the operating room. Although there were no differences in accuracy between the groups trained using AR and those trained by an expert surgeon, we believe the tool may be useful in education because it demonstrates that some motor skills for arthroplasty may be learned in an unsupervised setting. Future studies will evaluate AR-training for arthroplasty skills other than cup orientation and its transfer validity to real surgery. LEVEL OF EVIDENCE: Level I, therapeutic study.

Correlation between sperm motility and sperm chromatin/DNA damage before and after cryopreservation and the effect of folic acid and nicotinic acid on post-thaw sperm quality in normozoospermic men.

Cryopreservation exposes sperm to physical and chemical stresses causing cell damages and impairs sperm functions. The aim of this study was to evaluate the association between motility and sperm chromatin/DNA damage before and after cryopreservation and investigate the effects of folic acid and nicotinic acid on post-thaw sperm quality. Thirty semen samples were obtained from 30 normozoospermic men, aged between 25 and 45 years old. Each sample were divided into five aliquots to form the following groups: fresh, cryopreserved with sperm-freeze only (control), with nicotinic acid (10 mM), with folic acid (50 nM), and with a combination of folic acid (50 nM) + nicotinic acid (10 mM). Sperm viability and motility in each group were assessed by eosin-nigrosine staining and computer-aided sperm analysis respectively. Sperm chromatin quality was studied by aniline blue, toluidine blue, acridine orange staining methods and sperm chromatin dispersion test. Cryopreservation led to a significant reduction in sperm quality in comparison to fresh sample groups (p < 0.05). Sperm chromatin damage was negatively correlated with the percentage of progressively motile cells. Supplementation of the cryopreservation medium with folic acid or nicotinic acid induced a significant improvement in sperm parameters and chromatin quality, compared to control groups (p < 0.05). Meanwhile, the combination of folic acid + nicotinic acid showed a significant protective effect in post thaw sperm. In conclusion, cryopreservation generated oxidative stress, inducingsperm cryodamage, reducing progressive motility and sperm quality, as an indicator of significant chromatin/DNA damage. Folic acid and nicotinic acid exhibited a potential cryoprotective effect by enhancing sperm quality.

Effect of preservation of human semen sample at 4-6 and 25 °C on sperm motility.

Sperm motility is the result of transverse movements that exist along its tail. It plays an important role in male fertility. The aim of this study was to evaluate the influence of keeping washed normozoospermic semen samples at 4-6 and 25 °C on the motility of spermatozoa. 26 semen samples of normozoospermic were washed twice in modified Ham's F10 medium. Then, thirteen of the semen samples were kept in refrigerator (4-6 °C) and the remaining samples were stored in incubator (25 °C) for 12 days. On the 0 (immediately after sampling as control group), 1st, 2nd, 5th, 7th and the 12th days, the percentage of fast progressive (grade a), slow progressive (grade b), non-progressive (grade c) and immotile (grade d) sperm cells were calculated for each temperature. The data obtained from this study showed that the percentages of a, b and c grades of motile spermatozoa were significantly decreased (p < 0.001) during 12 days at the both temperatures but reduction of these percentages has a gentle slope at 4-6 °C. There was no motile sperm after 12 days of storage. This study suggests that motile spermatozoa could be retrieved up to 7 days after the storage of washed normozoospermic men semen samples at 4-6 and 25 °C. Also, there were no motile sperm cells 12 days after sampling.

Outcomes of Dual Mobility Bearings in Revision Total Hip Replacements.

Background Dual mobility bearings have gained attention in the prevention of instability in revision total hip replacement. This study aimed to evaluate the use of dual mobility bearings in revision total hip replacement. The primary outcome was the rate of dislocation. Secondary outcomes included the rate of re-operation for any reason, surgical complications, serious medical adverse events, and 90-day mortality rate. Methods A single-centre case series of 55 consecutive operations in 49 patients who underwent revision total hip replacement using dual mobility bearings with a minimum follow-up of three months was studied.  Results Early dislocation occurred in one case (2%), and there were no intra-prosthetic dislocations at a mean follow-up of 16 months. The rate of re-operation for any reason was 6/55 (11%) cases, and the post-operative infection rate was 2/55 (4%) cases. Serious medical adverse events occurred in 2/55 (4%) cases. The 90-day mortality rate was 1/55 (2%) cases. Two cases (2%) had cup abduction or anteversion angles outside of the safe zones although there were no dislocations in these patients. Conclusion This case series demonstrates a low dislocation rate in the early post-operative period for dual mobility bearings in revision total hip replacement. Dual mobility bearings show promise as an early low dislocation implant in revision total hip replacement. It remains to be determined whether dual mobility bearings are low-wear implants in the long term.

Investigation of the effects of thymoquinone (TQ) and polyvinylpyrrolidone (PVP) on the motility, viability, and chromatin status of sperm in normozoospermic semen samples.

Objective: Adverse effects of polyvinylpyrrolidone (PVP) on sperm membrane and chromatin have been proven in many studies. Among the natural products proposed as an alternative for PVP, thymoquinone (TQ)-a major constituent of Nigella sativa plant- has been suggested as a potential natural spermostasis. Therefore, this study aimed to compare the effects of TQ with PVP for sperms motility, survival, DNA denaturation, and DNA fragmentation in normozoospermic men (men with a normal or healthy sperm profile). Methods: An experimental trial was carried out on 30 normozoospermic men of the Andrology Unit of (Shahid Beheshti Hospital, Isfahan, Iran). Each washed semen samples were divided into four fractions and was randomly treated with TQ (50 µg/ml), %5 PVP, and %10 PVP (M/V) which was compared to untreated fraction (control). Results: There was a significant difference between the four groups in terms of motility, viability, DNA denaturation, and fragmentation (P <0.05). TQ caused sperm immobility, while 5% PVP and 10% PVP decreased (98 and 99%, respectively) sperm motility compared to control. TQ did not affect sperm viability compared to the control group, but PVP decreased it. Besides, TQ did not affect DNA denaturation and fragmentation, but PVP increased it. Conclusion: TQ could be used as an alternative natural spermostasis with less adverse effects rather than PVP which causes more efficient immobilization and isolation of individual sperm cells.

Accuracy of Total Hip Arthroplasty Templating Using Set Calibration Magnifications.

Background Templating for total hip arthroplasty has been adopted over recent decades as a reliable and accurate method for pre-operative planning. The use of calibration markers for this process provides a recognised benefit at the expense of cost, availability and error. Many surgeons use a set magnification of 118% to account for calibration errors when templating total hip arthroplasty. This study aims to assess the accuracy of templating with standardised magnifications and assess the effect of BMI on templating accuracy. Materials and methods A retrospective analysis was performed using a single-surgeon series of 119 consecutive total hip arthroplasties. Anteroposterior radiographs were taken pre- or post-operatively without calibration hardware. Pre-operatively, the total hip arthroplasty was templated on TraumaCad (BrainLab Inc, Westchester, IL) using either 118% or 119% calibration magnification. Post-operative magnification was calibrated using the known femoral head diameter. Templated and implanted prostheses were compared for size. Results At 118%, 61.1% of cups matched those templated with 96.3% of cups within two sizes. At 119%, 52.5% of cups used matched their templates with 100% within two sizes. There was no significant difference between 118% and 119% cup size prediction (p=0.49). A trend was noticed in increasing magnification error with increasing BMI. However, BMI had no significant effect on the accuracy of templating cup size within two cup sizes (p=0.58). Conclusion. Templating acetabular cups using a set magnification of 118% or 119% yields accurate results and provides a reliable method to template without calibration equipment. Whilst BMI can affect magnification error, this has no significant effect on the accuracy of implanted cups and stems within two sizes.

Subsidence in Centraliser Sign: A Novel Tool to Help Predict Early Subsidence in Periprosthetic Femoral Fractures Around Polished Tapered Stems Treated With Internal Fixation.

Background When treating periprosthetic femoral fractures (PPF) around polished taper slip stems (PTS), determining which patients can be successfully treated with internal fixation can be challenging. We have described the subsidence-in-centraliser (SINC) sign as a radiographic feature of PPF around PTS stems. We hypothesise that a positive SINC sign can help predict a poorer outcome for the fixation of these fractures. Patients and methods Retrospective identification of PPFs around cemented PTS with an appreciable centraliser on radiographs was conducted at a single centre. A positive SINC sign was defined as a post-injury radiograph demonstrating >50% reduction in the radiographic lucency representing the stem centraliser when compared to pre-injury films or complete obliteration of distal lucency when no pre-injury film was available. The primary outcome was the rate of subsequent stem subsidence on follow-up radiographs comparing SINC-positive and SINC-negative fractures, which were managed with open reduction and internal fixation (ORIF). Results Fifty-four patients were included in the analysis. The mean age was 76.8 years, and the mean follow-up for all patients was 12.7 months. Thirty-five fractures were deemed SINC-positive, and 19 were SINC-negative. 17/17 (100%) SINC-positive fractures managed with fixation underwent further subsidence (mean 5.4 mm, SD 2.8). A positive SINC sign demonstrated a sensitivity of 90.5% and specificity of 100% for subsequent stem subsidence in fractures treated without revision. SINC positive fractures underwent significantly more subsidence compared with SINC negative fractures when fixed (5.4 mm vs. 0.28 mm, U = 6.50, p<0.001) at a mean follow-up of 12.7 months. The SINC sign demonstrated strong inter- (k=0.96) and intra-rater (k=0.86) reliability. Conclusion The SINC sign can serve as a useful adjunct in the decision to fix or revise PPF around PTS. A positive SINC sign may represent a cement mantle that cannot be reconstituted anatomically, leading to subsidence after treatment with ORIF.

Quantifying the contribution of pincer deformity to femoro-acetabular impingement using 3D computerised tomography.

OBJECTIVE: To provide a simple, reliable method for the three-dimensional quantification of pincer-type hip deformity. MATERIALS AND METHODS: Computerised tomography scans of 16 normal female hips and 15 female hips with clinical femoro-acetabular impingement (FAI) and radiographic signs of pincer secondary to acetabular protrusio were analysed. After orientating the pelvis in the anterior pelvic plane, the acetabular centre was determined, and the ratios of its coordinates to the corresponding pelvic dimensions were calculated. Acetabular coverage of the femoral head and centre-edge angles were also measured for the two groups. RESULTS: In hips with a pincer, the hip was medialised by 37 % (p = 0.03), more proximal by 5 % (p = 0.05) and more posterior by 9 % (p = 0.03) compared with the normal hips. Coverage of the femoral head in protrusio hips was significantly greater than normal (average 71 % vs 82 %, p = 0.0001). Both the lateral centre-edge angle and the combined anterior-posterior centre-edge angle were greater in protrusio hips than in the normal ones (48° vs 37 °, p < 0.001; and 216° vs 176°, p < 0.0001 respectively). CONCLUSION: Displacement in acetabular protrusio occurs in all planes. This CT-based method allows for the accurate and standardised quantification of the extent of displacement, as well as 3D measurement of femoral head coverage. In the adult female population, a combined centre-edge angle of over 190° suggests an acetabulum that is too deep and a potential cause of symptoms of femoro-acetabular impingement. Conversely, an acetabulum that has a combined centre-edge angle of less than 190° may be considered to be of normal depth, and therefore not contributing a pincer to FAI should it occur.

Length-change patterns of the collateral ligaments after total knee arthroplasty.

PURPOSE: Total knee arthroplasty (TKA) is a procedure with function dependent upon correct tensioning of the soft-tissue constraints. The purpose of this study was to examine the length-change behaviour of the collateral ligaments during knee flexion-extension before and after TKA. The influence of differing degrees of internal-external rotation of the femoral component on slackening/tightening of the collateral ligaments during knee flexion was to be studied. METHODS: The length-change patterns of the collateral ligaments were measured in eight intact knees in vitro: sutures were passed along the ligaments and attached to displacement transducers. Measurements were repeated after TKA with the femoral component in neutral rotation, then with 5° internal and 5° external rotation. RESULTS: Both the MCL and LCL slackened during knee flexion from 0° to 110° flexion, at all stages of the experiment. In the native knee, the MCL slackened 2 mm, whilst the LCL slackened 7 mm. The MCL slackened a further 3 mm and the LCL a further 4 mm during flexion post-TKA. A 5° external rotation of the femoral component slackened the MCL 2 mm more and tightened the LCL by 2 mm. The opposite effects resulted from 5° internal rotation. CONCLUSIONS: The collateral ligaments slackened more than normal following TKA, and these length changes were increased by femoral component rotation. External rotation of the femoral component to address patellar tracking may slacken the MCL and thus lead to valgus instability in the flexed knee.

Telemedicine in orthopaedics during COVID-19 and beyond: A systematic review.

INTRODUCTION: Telemedicine is the delivery of healthcare across a distance using some form of communication technology. The COVID-19 pandemic has led to increased adoption of telemedicine with national orthopaedic governing bodies advocating its use, as evidence suggests that social distancing maybe necessary until 2022. This systematic review aims to explore evidence for telemedicine in orthopaedics to determine its advantages, validity, effectiveness and utilisation. METHODS: Databases of PubMed, Web of Science, Scopus and CINAHL were systematically searched and articles were included if they involved any form of telephone or video consultation in an orthopaedic population. Findings were synthesised into four themes: patient/clinician satisfaction, accuracy and validity of examination, safety and patient outcomes and cost effectiveness. Quality assessment was undertaken using Cochrane and Joanna Briggs Institute appraisal tools. RESULTS: Twenty-one studies were included consisting of nine randomised controlled trials (RCTs). Studies revealed high patient satisfaction with telemedicine for convenience, less waiting and travelling time. Telemedicine was cost effective particularly if patients had to travel long distances, required hospital transport or time off work. No clinically significant differences were found in patient examination nor measurement of patient-reported outcome measures. Telemedicine was reported to be a safe method of consultation. DISCUSSION: Evidence suggests that telemedicine in orthopaedics can be safe, cost effective, valid in clinical assessment and with high patient/clinician satisfaction. However, more high-quality RCTs are required to elucidate long-term outcomes. This systematic review presents up-to-date evidence on the use of telemedicine and provides data for organisations considering its use during the COVID-19 pandemic and beyond.

Clinical value of SPECT/CT for evaluation of patients with painful knees after total knee arthroplasty--a new dimension of diagnostics?

BACKGROUND: The purpose of our study was to evaluate the clinical value of hybrid SPECT/CT for the assessment of patients with painful total knee arthroplasty (TKA). METHODS: Twenty-three painful knees in patients following primary TKA were assessed using Tc-99m-HDP-SPECT/CT. Rotational, sagittal and coronal position of the TKA was assessed on 3D-CT reconstructions. The level of the SPECT-tracer uptake (0-10) and its anatomical distribution was mapped using a validated localization scheme. Univariate analysis (Wilcoxon-Mann-Whitney, Spearmean's-rho test, p < 0.05) was performed to identify any correlations between component position, tracer uptake and diagnosis. RESULTS: SPECT/CT imaging changed the suspected diagnosis and the proposed treatment in 19/23 (83%) knees. Progression of patellofemoral OA (n = 11), loosening of the tibial (n = 3) and loosening of the femoral component (n = 2) were identified as the leading causes of pain after TKA.Patients with externally rotated tibial trays showed higher tracer uptake in the medial patellar facet (p = 0.049) and in the femur (p = 0.051). Patients with knee pain due to patellofemoral OA showed significantly higher tracer uptake in the patella than others (p < 0.001). CONCLUSIONS: SPECT/CT was very helpful in establishing the diagnosis and guiding subsequent management in patients with painful knees after TKA, particularly in patients with patellofemoral problems and malpositioned or loose TKA.

Combined single photon emission computerised tomography and conventional computerised tomography (SPECT/CT) in patellofemoral disorders: a clinical review.

Patellofemoral disorders are common conditions seen in a knee clinic but can present a great diagnostic challenge to the orthopaedic surgeon. Combined single photon emission computerised tomography with conventional computer tomography (SPECT/CT) provides the clinician with precise anatomical and physiological information of the patellofemoral joint. We present a clinical review that highlights the value of SPECT/CT in patients with patellofemoral disorders, where other modalities such as radiographs, MRI, and conventional CT did not provide sufficient information. SPECT/CT has proven to be helpful for establishing the diagnosis and guidance for further treatment. SPECT/CT should be recognised as a valuable diagnostic tool in orthopaedic patients.

Fixation and Implant Retention of Extracapsular Femoral Neck Periprosthetic Fractures Around Hip Resurfacing Arthroplasty - A Case Series.

BACKGROUND: Extracapsular femoral neck fractures in the presence of a resurfacing hip arthroplasty (RHA) appear to be independent of suboptimal technique during the initial implantation of the RHA and present with a similar etiology as native hip fractures - that is, a fragility fracture related to pathological or age-related osteoporosis, as a consequence of trauma. In the presence of a well-fixed and previously well-functioning RHA, the options for management include revision arthroplasty or open reduction and internal fixation (ORIF). In the absence of loosening through mechanisms of wear, infection, metallosis, or suboptimal prosthesis positioning, many authors have advocated ORIF with implant retention. However, there is often debate regarding the use of total hip arthroplasty in these cases. CASE SERIES: The authors conducted a thorough assessment of the literature followed by a retrospective review of outcomes for three patients treated by ORIF with implant retention for extracapsular femoral neck fractures around a RHA, using a standardized technique. All patients were independently mobile and active with well-fixed and well-functioning RHAs before the date of injury. All patients suffered low-energy trauma resulting in the fracture. There were no intraoperative or perioperative complications. All patients achieved full weight-bearing status and independent mobility. Two patients achieved radiographic union and returned to full range of movement and independent mobilization comparable to their preoperative state. One patient was lost to follow-up. CONCLUSION: The authors believe that fixation of extracapsular proximal femoral fractures distal to a well-fixed, well-functioning RHA is a good management option in an independent and active patient. A higher level of evidence is needed to investigate the surgical management options of these injuries comparing osteosynthesis with revision arthroplasty.

Bilateral osteochondral defects of the patellae in an 11-year-old girl.

Osteochondral defect or osteochondritis dissecans (OCD) of the knee usually affects young, active populations. It is a challenging diagnosis as patients typically present with poorly localised activity-related pain, which is non-specific and covers many differentials. We present an active 11-year-old girl with bilateral osteochondral defects of the patellae: a rare clinical disorder which was affecting her sporting activities. She had a 12-month history of bilateral anterior knee pain before the diagnosis was achieved with appropriate imaging. Her pain significantly improved with activity modification and physiotherapy. Follow-up will require outpatient clinic assessment and imaging to determine if non-operative management continues to be successful or surgery may be required. This case report emphasises the importance of appropriate high index of suspicion when managing patients with non-specific knee pain. It also demonstrates the importance of judicious use of imaging to avoid a missed or delayed diagnosis.

Cams and pincer impingement are distinct, not mixed: the acetabular pathomorphology of femoroacetabular impingement.

BACKGROUND: Many impinging hips are said to have a mix of features of femoral cam and an overcovered acetabulum causing pincer impingement. Correction of such a mixed picture by reduction of the cam lesion and the acetabular rim is the suggested treatment. QUESTIONS/PURPOSES: We therefore asked two questions: (1) Is the acetabulum in cam impingement easily distinguishable from the pincer acetabulum, or is there a group with features of both types of impingement? (2) Is version or depth of socket better able to distinguish cam from pincer impingement? METHODS: We analyzed the morphologic features of the acetabulum and rim profile of 20 normal, healthy hips, 20 with cams and 20 with pincers on CT. Pelvises were digitized, orientated to the best-fit acetabular plane, and a rim profile was plotted. RESULTS: Cam hips were shallower than normal hips, which in turn were shallower than pincer hips (84 degrees +/- 5 degrees versus 87 degrees +/- 4 degrees versus 96 degrees +/- 5 degrees, respectively). The rim planes of cam, normal, and pincer hips had similar version (23 degrees, 24 degrees, 25 degrees), but females were 4 degrees more anteverted than males. CONCLUSIONS: We concluded cam and pincer hips are distinct pathoanatomic entities. Cam hips are slightly shallower than normal, whereas pincers are deeper. CLINICAL RELEVANCE: Before performing surgery for cam-type femoroacetabular impingement, surgeons should consider measuring the acetabular depth. The cam acetabulum is shallower than normal and may be rendered pathologically shallow by acetabular rim resection leading to early joint failure.

The geometry of the trochlear groove.

BACKGROUND: In the natural and prosthetic knees the position, shape, and orientation of the trochlea groove are three of the key determinants of function and dysfunction, yet the rules governing these three features remain elusive. QUESTIONS/PURPOSE: The aim was to define the three-dimensional geometry of the femoral trochlea and its relation to the tibiofemoral joint in terms of angles and distances. METHODS: Forty CT scans of femurs of healthy patients were analyzed using custom-designed imaging software. After aligning the femur using various axes, the locations and orientations of the groove and the trochlear axis were examined in relation to the conventional axes of the femur. RESULTS: The trochlear groove was circular and positioned laterally in relation to the mechanical, anatomic, and transcondylar axes of the femur; it was not aligned with any of these axes. We have defined the trochlear axis as a line joining the centers of two spheres fitted to the trochlear surfaces lateral and medial to the trochlear groove. When viewed after aligning the femur to this new axis, the trochlear groove appeared more linear than when other methods of orientation were used. CONCLUSIONS: Our study shows the importance of reliable femoral orientation when reporting the shape of the trochlear groove.

Combined single-photon emission computerized tomography and conventional computerized tomography (SPECT/CT): clinical value for the knee surgeons?

Single-photon emission computerized tomography in combination with conventional computer tomography (SPECT/CT) is an emerging technology that may hold great clinical value to the orthopaedic knee surgeon. Post-operative knee pain is a familiar condition seen in most orthopaedic clinics. Here, we present the value of SPECT/CT in three such cases of pain after surgical treatment of knee osteoarthritis (high tibial osteotomy, medial unicompartmental arthroplasty, total knee arthroplasty). In these patients with post-operative knee pain, SPECT/CT has proved to be beneficial in establishing the diagnosis and providing guidance for further treatment.

A novel standardized algorithm for evaluating patients with painful total knee arthroplasty using combined single photon emission tomography and conventional computerized tomography.

SPECT/CT is a promising diagnostic modality in patients with painful total knee arthroplasty (TKA). The purpose of this study is to introduce a novel standardized SPECT/CT algorithm and evaluate its clinical application and reliability. A novel SPECT/CT localization scheme consisting of 9 tibial, 9 femoral and 4 patellar regions on standardized axial, coronal and sagittal slices is proposed. It was piloted in 18 consecutive patients with post TKA pain. The tracer activity on SPECT/CT was recorded using a color-coded scale (0-10). The inter- and intra-observer reliability was assessed for localization and tracer activity. The prosthetic component position was assessed in the CT images after 3D reconstruction using standardized frames of reference. The median inter- and intra-observer differences and ranges of the measured angles were calculated along with the ICC values for inter- and intra-observer reliability. The localization scheme showed very high inter- and intra-observer reliabilities for all regions. The measurement of component position was highly reliable in all cases with sufficient visibility of anatomical landmarks. The median inter-observer difference between alignment measurements for tibial and femoral components was less than 3 degrees (range 0 degrees -6 degrees ). The median intra-observer variability for these was less than 2 degrees (range 0 degrees -5 degrees ). The SPECT/CT algorithm presented is both reliable and useful in the management of patients with painful TKA. It combines biomechanical and metabolic data (tracer localization) providing an extra dimension to the understanding of this difficult condition. The clinical value of SPECT/CT in patients with unexplained pain following TKA should be further investigated.

Can the acetabular position be derived from a pelvic frame of reference?

Acetabular center positioning has an effect on hip function. However, reported clinical and plain radiographic methods are inaccurate and unreliable for ascertaining acetabular implant location. In an exploratory study we asked whether the normal acetabular position can be derived from simple radiographically measurable pelvic dimensions. We analyzed computed tomographic scans of 37 normal hips using a pelvic frame of reference centered on the ipsilateral anterior-superior iliac spine. We defined the x-, y-, and z-coordinates of the hip center (C(x),C(y),C(z)) as a percentage of the corresponding pelvic dimensions (D(x),D(y),D(z)). C(x)/D(x) averaged 9%, C(y)/D(y) 34%, and C(z)/D(z) 37%. These ratios had narrow distributions with small confidence intervals. Interobserver agreement tests showed a mean intraclass correlation coefficient of 0.95. We observed gender differences in the ratios of as much as 4%, which correspond to differences of as much as 9 mm in the hip center position. The ratios provide a simple and reliable way of deriving the normal position of the hip center from the pelvic dimensions alone. This gives the surgeon a simple way of planning where the hip center should be and may be particularly helpful in revision hip arthroplasty or in cases involving extensive osteophytes, dysplasia, or protrusio.