Aims. The aims of this study were to develop an in vivo model of periprosthetic joint infection (PJI) in cemented hip hemiarthroplasty, and to monitor infection and biofilm formation in real-time. Methods. Sprague-Dawley rats underwent cemented hip hemiarthroplasty via the posterior approach with pre- and postoperative gait assessments. Infection with Staphylococcus aureus Xen36 was monitored with in vivo photoluminescent imaging in real-time. Pre- and postoperative gait analyses were performed and compared. Postmortem micro (m) CT was used to assess implant integration; field emission scanning electron microscopy (FE-SEM) was used to assess biofilm formation on prosthetic surfaces. Results. All animals tolerated surgery well, with preservation of gait mechanics and weightbearing in control individuals. Postoperative in vivo imaging demonstrated predictable evolution of infection with logarithmic signal decay coinciding with abscess formation. Postmortem mCT qualitative volumetric analysis showed high contact area and both cement-bone and cement-implant interdigitation. FE-SEM revealed biofilm formation on the prosthetic head. Conclusion. This study demonstrates the utility of a new, high-fidelity model of in vivo PJI using cemented hip hemiarthroplasty in rats. Inoculation with bioluminescent bacteria allows for non-invasive, real-time monitoring of infection. Cite this article: Bone Joint J 2021;103-B(7 Supple B):9–16

Early micromotion of hip implants measured with radiostereometric analysis (RSA) is a predictor for late aseptic loosening. Computed Tomography Radiostereometric Analysis (CT-RSA) can be used to determine implant micro-movements using low-dose CT scans. CT-RSA enables a non-invasive measurement of implants. We evaluated the precision of CT-RSA in measuring early stem migration. Standard marker-based RSA was used as reference. We hypothesised that CT-RSA can be used as an alternative to RSA in assessing implant micromotions. We included 31 patients undergoing Total Hip Arthroplasty (THA). Distal femoral stem migration at 1 year was measured with both RSA and CT-RSA. Comparison of the two methods was performed with paired-analysis and Bland-Altman plots. Furthermore, the inter- and intraobserver reliability of the CT-RSA method was evaluated. No statistical difference was found between RSA and CTMA measurements. The Bland-Altman plots showed good agreement between marker-based RSA and CT-RSA. The intra- and interobserver reliability of the CT-RSA method was found to be excellent (≥0.992). CT-RSA is comparable to marker-based RSA in measuring distal femoral stem migration. CTMA can be used as an alternative method to detect early implant migration

Introduction. Patients with aseptic loosening, a cause of failure in uncemented total joint arthroplasty (TJA), often present with fibrous tissue at the bone-implant interface. 1. In this study, we characterize the presence of neutrophil extracellular traps (NETs) in the intramedullary fibrotic membrane of aseptic loosening patients. We further explore the role of NETs, mediated by peptidyl arginine deiminase (PAD4), in peri-implant fibrosis and osseointegration failure through a murine model of unstable tibial implantation. 2–4. Methods. Peri-implant membrane was retrieved from five patients during total hip revision surgery and analyzed for the presence of NETs (citH3+ with extracellular DNA) via immunofluorescence. A Ti-6Al-4V implant was inserted in an oversized drill-hole in the right proximal tibia of 8-week-old C57BL/6J and PAD4 knockout mice (n=3 per group). Fourteen days later, all mice were euthanized, and implanted tibias were dissected. Fibrosis and osseointegration at the bone-implant interface were assessed by micro-computed tomography (microCT) and hematoxylin and eosin (H&E) staining. H&E samples were scored blindly by the investigator and another observer for signs of poor (score=0) to excellent osseointegration (score=3) using a rubric established in our lab. Results. NETs were found in peri-implant membrane collected from aseptic loosening patients (Figure 1a) and at the bone-implant interface in a murine model (Figure 1b). Unstable implants in wild type mice failed to osseointegrate, indicated by presence of fibroblast-like cells (dashed arrow), immature bone matrix (Figure 1c), low bone volume fraction (BV/TV) and bone surface area (BS) (Figure 1e). Unstable implants in PAD4. −/−. mice showed signs of good osseointegration such as mature trabeculae (solid arrow) (Figure 1d), higher BV/TV (p<0.10) and BS (p<0.05) (Figure 1f). Histological osseointegration scoring indicated wildtype mice exhibited an average score of 0.83 and PAD4. −/−. exhibited an average score of 2.5 (p<0.05, weighted Cohen's kappa = 0.714) (Figure 1g). Conclusion. NETs were characterized in fibrotic tissue in both aseptic loosening patients and in a murine model of unstable tibial implantation. NET inhibition was able to successfully prevent peri-implant fibrosis and osseointegration failure, leading the way for a potential novel non-invasive therapeutic approach for the treatment of aseptic loosening. For any figures, tables, or references, please contact the authors directly

Objectives. Alarm over the reported high failure rates for metal-on-metal (MoM) hip implants as well as their potential for locally aggressive Adverse Reactions to Metal Debris (ARMDs) has prompted government agencies, internationally, to recommend the monitoring of patients with MoM hip implants. Some have advised that a blood ion level >7 µg/L indicates potential for ARMDs. We report a systematic review and meta-analysis of the performance of metal ion testing for ARMDs. Methods. We searched MEDLINE and EMBASE to identify articles from which it was possible to reconstruct a 2 × 2 table. Two readers independently reviewed all articles and extracted data using explicit criteria. We computed a summary receiver operating curve using a Bayesian random-effects hierarchical model. Results. Our literature search returned 575 unique articles; only six met inclusion criteria defined a priori. The discriminative capacity of ion tests was homogeneous across studies but that there was substantial cut-point heterogeneity. Our best estimate of the “true” area under curve (AUC) for metal ion testing is 0.615, with a 95% credible interval of 0.480 to 0.735, thus we can state that the probability that metal ion testing is actually clinically useful with an AUC ≥ 0.75 is 1.7%. Conclusion. Metal ion levels are not useful as a screening test for identifying high risk patients because ion testing will either lead to a large burden of false positive patients, or otherwise marginally modify the pre-test probability. With the availability of more accurate non-invasive tests, we did not find any evidence for using blood ion levels to diagnose symptomatic patients. Cite this article: M. Pahuta, J. M. Smolders, J. L. van Susante, J. Peck, P. R. Kim, P. E. Beaule. Blood metal ion levels are not a useful test for adverse reactions to metal debris: a systematic review and meta-analysis. Bone Joint Res 2016;5:379–386. DOI: 10.1302/2046-3758.59.BJR-2016-0027.R1

Background. Over 10% of total hip arthroplasty (THA) surgeries performed in England and Wales are revision procedures. 1. Malorientation of the acetabular component in THA may contribute to premature failure due to mechanisms such as edge loading and prosthetic impingement. It is known that the pelvis flexes and extends during activities of daily living (ADLs), and excessive pelvic motion can contribute to functional acetabular malorientation. Preoperative radiographs can be performed to measure changes in pelvic tilt during ADLs to identify high risk individuals and inform surgical decision making. However, radiographs require time-consuming radiation exposure, and are unable to provide truly dynamic 3-dimensional analysis. The purpose of this study was to develop and evaluate a motion capture method using inertial measurement units (IMUs). This would provide a rapid, non-invasive analysis of pelvic tilt which could be used to support surgical planning. Methods. Patients awaiting THA were fitted with a bespoke device consisting of a 3D-printed clamp which housed the IMU and positioned over the sacrum. A wide elastic belt was fitted around the patient's waist to keep the device in place. Movement data was transmitted wirelessly to a tablet computer. Pelvic tilt was measured in standing, flexed seated and step-up positions while undergoing X-rays with the IMU capturing the data in parallel. Statistical analysis included measures of correlation between the X-ray and IMU measurements. Results. Measurements from 30 patients indicated a moderate-strong correlation (R. 2. = .87; Figure 1) between IMU and radiological measures of AP pelvic tilt. Conclusions. A novel device has been developed that can suitably track pelvic movements. This could potentially be used to identify patients with large changes in pelvic tilt, and thereby inform surgical planning. For any figures or tables, please contact the authors directly

Background. Greater trochanteric pain syndrome (GTPS) is a common problem affecting 10–25% of the population. Physiotherapy, anti-inflammatories, corticosteroid injections and surgery have all been described in the management of GTPS, all with limited, temporal success. Extracorporeal shockwave therapy (ESWT) has been proposed as a potential management option for this difficult presentation. Method. We ran a prospective, 2 arm, single blinded, randomised control trial comparing focused shockwave therapy to an ultrasound guided corticosteroid injection. The primary outcome measure was the visual analogue pain score. Secondary outcome measures included the Harris hip score and Trendelenburg test for function; the SF-36 for quality of life (QoL); and a Likert scale question for a subjective assessment of symptom improvement. Results. 104 patients (10 males and 94 females), of mean age 61.5 years were recruited. 53 were randomised to receive ESWT and 51 to receive an image guided injection. 11 patients were lost to follow up. Baseline scores were equal between the groups. At 3 months, pain, function and QoL scores had improved in both groups. The Trendelenburg test was significantly improved in the ESWT group with 80% patients being negative compared to 80% positive at baseline (p<0.001). At 12 months, the improvement in Trendelenburg test was maintained in the ESWT group, but the injection group had reverted to baseline. Across all outcomes, the ESWT group had significantly improved scores compared to the injection group; VAS 3.71 versus 5.50 (p=0.007, 95% confidence interval 0.63 to 3.08), HHS 69.7 vs 57.5 (p=0.002, 95% confidence interval −20.0to −4.6) and SF-36 52.4 vs 47.7 (p=0.048, 95% confidence interval −9.31 to −0.04). Conclusions. We have shown focused ESWT is an effective treatment for patients with GTPS. We hope to advocate ESWT as an effective non-invasive treatment modality for this challenging patient population

Clinical graphics allows creation of three dimensional simulation based on CT or MRI that allows pre-operative planning. The software reports several hip morphological parameters routinely. Our aim was to validate the measurements of acetabular morphological parameters using CT based clinical graphics in patients presenting with symptomatic hip pain. We reviewed standardised plain radiographs, CT scans and 3D clinical graphics outputs of 42 consecutive hips in 40 patients presenting with symptomatic hip pain. Acetabular index (AI), lateral centre edge angle (LCE), acetabular and femoral version measurements were analysed for the 3D clinical graphics with radiographs and CT as gold standard. Significant differences were noted in measurements of AI, LCE, acetabular version and femoral version using the 3D motion analysis versus conventional measures, with only acetabular version showing comparable measurements. Correlation between 3D clinical graphics and conventional measures of acetabular morphology (AI, LCE) showed only slight agreement (ICC <0.4); while substantial agreement was noted for acetabular and femoral version (IC > 0.5). Acetabular morphological parameters measured by 3D clinical graphics are not reliable or validated. While clinicians may pursue the use of 3D clinical graphics for preoperative non-invasive planning, caution should be exercised when interpreting the reports of hip morphological parameters such as AI and LCE

Introduction. Failure of metal on metal (MOM) total hip arthroplasty (THA) and resurfacing arthroplasty (HRA) due to development of adverse local tissue reaction (ALTRs) is a significant problem. The prevalence of ALTRs in asymptomatic MOM arthroplasty patients is highly variable. The purpose of this prospective, longitudinal study was to: 1) determine MRI ALTR prevalence in patients with HRA; 2) determine if patients with HRA have a greater rate of MRI ALTRs compared to control patients with ceramic on poly (COP) THA; and 3) evaluate changes in patient reported outcomes between these implant designs. Methods. Following IRB approval with informed consent, self-reported asymptomatic primary COP and HRA patients greater than one year post arthroplasty were evaluated with 4 annual (TP1–4) MRIs using a standardized protocol and serum ion level testing. Morphologic and susceptibility reduced images were acquired for each hip and evaluated for synovial thickness, volume, capsule dehiscence and the presence of ALTR. Patient reported outcomes were evaluated by Hip Disability and Osteoarthritis Outcome Scores (HOOS). Analyses were performed to detect differences of synovial thickness and volume, and HOOS subgroups between and within bearing surfaces at each time point and over time, and to compare the time to and the risk of developing MRI ALTR. Analyses were adjusted for age, gender, and length of implantation. Results. 86 hips were evaluated at the initial time point (TP1): HRA, n=41, age=58±8 y.o., 34/7 (M/F); COP, n=45, age=65±9 y.o., 22/23 (M/F). The mean synovial volume of the subjects was similar at TP1, and the synovial volume in HRA subjects increased significantly from TP1 to TP4 (mean volume difference=9 cm3, p=0.031) while COP subjects displayed a minimal increase from TP1 to TP4 (mean volume difference =0.3 cm3, p=0.9). The synovial volume in HRA subjects tended to be larger and with greater variability than COP subjects at TP4 (HRA=15±58 cm3; COP=6 ±10 cm3, p=0.3). By TP4, MRI ALTRs developed in 13/41 HRA subjects (mean time to ALTR=1.5 yr) compared to 2/25 COP subjects (mean time to ALTR=2.0 yr), p=0.001. While risk of MRI ALTRs in HRA subjects was 9.9 times the risk in COP subjects (p=0.07), 68% of HRA subjects did not have an MRI ALTR present. Significant differences of [Co] and [Cr] in HRA subjects with MRI ALTR present were not detected at 2/4 time points and 1/4 time points, respectively, and there were no significant differences in ion levels in the COP group. The HOOS sub-scores of Pain and Activity of Daily Living scores of HRA subjects were similar to COP subjects, and HRA subjects had better Sporting Ability than COP subjects at all time points. HRA subjects had higher Symptoms at TP1 (p=0.016) but both cohorts had high scores (HRA=92.3/100; COP=87.7/100). Initially dehiscent posterior capsules of HRA subjects (9%) tended not to resolve (10/11, 91%), while dehiscent COP subjects (15%) had greater resolution (6/22, 27%). The presence of osteolysis was limited (HRA: 6/41; COP: 3/45; p=0.101). Conclusion. A greater synovial volume and higher rate of MRI ALTRs was found in HRA subjects, while the patient symptomatology via HOOS remained slightly better in HRA subjects than COP subjects, suggesting a poor association between MRI ALTRs and symptoms. The presence of posterior decompression of the posterior capsule into the bursa alone was not necessarily indicative of an ALTR, and is likely a normal postoperative finding. The inconsistent findings of the serum ion level testing further supports MRI as a non-invasive imaging modality capable of assessing peri-prosthetic soft tissue complications, and should be considered as part of the routine patient follow up to allow early detection and monitoring of ALTRs

Circulating cobalt and chromium from metal-on-metal implants cause rare but fatal autopsy-diagnosed cardiotoxicity. Concern exists that milder cardiotoxicity may be common and under-recognized. Unacceptably high failure rates of metal-on-metal hip implants have prompted regulatory authorities to issue worldwide safety alerts. Despite this, approximately 1 million patients continue to live with metal-on-metal implants, putting them at risk of systemic toxicity. Although blood cobalt and chromium levels are easily measured and track local toxicity, no non-invasive tests for organ deposition exist. We recently demonstrated the utilisation of a T2* protocol (cardiovascular MRI) to detect cobalt and chromium deposition within the liver of a patient with elevated blood cobalt levels (confirmed by liver biopsy tissue analysis and X-ray fluorescence spectroscopy). We sought to detect and constrain the correlation between blood metal ions and a comprehensive panel of established markers of early cardiotoxicity. In addition we applied T2* protocols with the aim of detecting cardiac metal deposition. 90 patients were recruited through RNOH clinics into this prospective single centre blinded study. Patients were divided into 3 age and gender-matched groups according to type of implant and blood metal ion levels as follows: [Group A] Non-metal bearing hip implants; [Group B] Metal-on-metal implants, low blood metal ion levels (<7ppb); and [Group C] Metal-on-metal implants, high blood levels (>7ppb). All underwent detailed cardiovascular phenotyping using cardiac MRI (with T2*, T1 and ECV mapping, in addition to LV size and ejection fraction), advanced echocardiography (LV size and ejection fraction), and cardiac blood biomarker (Troponin and BNP) sampling in the same sitting at the Heart Hospital London. Primary outcomes were pre-specified. See study flow diagram – figure 1. (The study was registered with . clinicaltrials.gov. : NCT02331264). Blood cobalt levels were significantly different between groups (0.17ppb (range 0·10–0·47, SD 0·08) vs. 2·47 (0·72–6·9, SD 1·81) vs. 30·0 (7·54–118.0, SD 29·1) respectively for groups A, B and C). No significant between-group differences were found for LV size, ejection fraction (CMR or echocardiography), LA size, T1, T2*, ECV, BNP or troponin, with all results within normal ranges. There was no relationship between blood cobalt levels and either left ventricular ejection fraction or T2* (r=-0·022 and r=-0·108 respectively). Although small, the study was sufficiently powered to detect, as a minimum, a difference in ejection fraction of 4.8% (Cohen's d effect size 0·8). Using best available technologies, exposure of patients with metal-on-metal hip implants to high (but not extreme) blood cobalt and chromium levels has no detectable effect on the heart. We believe these findings will offer reassurance to one million patients worldwide living with a metal-on-metal hip implant and will support clinicians caring for such patients. For any figures or tables, please contact the authors directly by clicking on ‘Info & Metrics’ above to access author contact details

We performed dynamic MRI of the femoral head within 48 hours of injury on 22 patients with subcapital fracture of the neck of the femur and on a control group of 20 of whom ten were healthy subjects and ten were patients with an intertrochanteric fracture. Three MRI patterns emerged when the results between the fractured side and the contralateral femoral head were compared. In all of the control group and in those patients who had undisplaced fractures (Garden stages I and II), perfusion of the femoral head was considered to be at the same level as on the unaffected side. In patients with displaced fractures (Garden stages III and IV) almost all the femoral heads on the fractured side were impaired or totally avascular, although some had the same level of perfusion as the unaffected side. We conclude that dynamic MRI, a new non-invasive imaging technique, is useful for evaluating the perfusion of the femoral head

We carried out radial MRI in 30 hips with moderate osteoarthritis and in ten normal hips. On a scout view containing the entire acetabular rim, 12 vertical radial slices were set at 15° intervals. Different appearances were observed in different parts of the joint. In the weight-bearing portion, from 45° anterosuperior to 45° posterosuperior, ‘attenuation’ (n = 16) and ‘disappearance’ (n = 25) were observed as abnormalities of the labrum with ‘capsular stripping’ (n = 29) and ‘extraosseous high signal lesion’ (n = 27) as capsular abnormalities, seen more often in the anterosuperior portion. In all 12 planes there were osteophytes on the acetabular edge (n = 24), femoral head (n = 22) and/or at the central acetabulum (n = 6), a bone cyst on the acetabulum (n = 18) and/or the femoral head (n = 9), irregularity of the articular cartilage (n = 30), and an effusion (n = 28). Our findings indicate that radial MRI may be a useful non-invasive diagnostic method for demonstrating pathology in moderate osteoarthritis of the hip

In a prospective, controlled study, we measured the effect on cardiac output of the introduction of methylmethacrylate during hemiarthroplasty for displaced fractures of the femoral neck. We treated 20 elderly patients who were similar in age, height, weight and preoperative left ventricular function with either cemented or uncemented hemiarthroplasty. Using a transoesophageal Doppler probe, we measured cardiac output before incision and at six stages of the procedure: during the surgical approach, reaming and lavage of the femoral canal, the introduction of cement, the insertion of the prosthesis, and in reduction and closure. We found that before the cement was introduced, there was no difference in stroke volume or cardiac output (p > 0.25). Cementation produced a transient but significant reduction in cardiac output of 33% (p < 0.01) and a reduction in stroke volume of 44% (p < 0.02). The introduction of cement did not affect the heart rate or mean arterial pressure. There was no significant difference in cardiac function on insertion of the prosthesis. Standard non-invasive haemodynamic monitoring did not detect the cardiovascular changes which may account for the sudden deaths that sometimes occur during cemented hemiarthroplasty. The fall in stroke volume and cardiac output may be caused by embolism occurring during cementation, but there was no similar fall during reaming or insertion of the prosthesis

Aims

To develop a core outcome set of measurements from postoperative radiographs that can be used to assess technical skill in performing dynamic hip screw (DHS) and hemiarthroplasty, and to validate these against Van der Vleuten’s criteria for effective assessment.

Aims

Cementless femoral stems must be correctly sized and well-seated to obtain satisfactory biological fixation. The change in sound that occurs during impaction of the femoral broach is said to indicate good fit, but this has not been widely studied. We set out to find whether the presence or absence of these sound changes could predict correct sizing.

We evaluated an operative technique, described by the Exeter Hip Unit, to assist accurate introduction of the femoral component. We assessed whether it led to a reduction in the rate of leg-length discrepancy after total hip arthroplasty (THA).

A total of 100 patients undergoing THA were studied retrospectively; 50 were undertaken using the test method and 50 using conventional methods as a control group. The groups were matched with respect to patient demographics and the grade of surgeon. Three observers measured the depth of placement of the femoral component on post-operative radiographs and measured the length of the legs.

There was a strong correlation between the depth of insertion of the femoral component and the templated depth in the test group (R = 0.92), suggesting accuracy of the technique. The mean leg-length discrepancy was 5.1 mm (0.6 to 21.4) pre-operatively and 1.3 mm (0.2 to 9.3) post-operatively. There was no difference between Consultants and Registrars as primary surgeons. Agreement between the templated and post-operative depth of insertion was associated with reduced post-operative leg-length discrepancy. The intra-class coefficient was R ≥ 0.88 for all measurements, indicating high observer agreement. The post-operative leg-length discrepancy was significantly lower in the test group (1.3 mm) compared with the control group (6.3 mm, p < 0.001).

The Exeter technique is reproducible and leads to a lower incidence of leg-length discrepancy after THA.

Cite this article: Bone Joint J 2015;97-B:154–9.

A high radiographic inclination angle (RI) contributes to accelerated wear and has been associated with dislocation after total hip arthroplasty (THA). With freehand positioning of the acetabular component there is a lack of accuracy, with a trend towards a high radiographic inclination angle. The aim of this study was to investigate whether the use of a digital protractor to measure the operative inclination angle (OI) could improve the positioning of the acetabular component in relation to a ‘safe zone’.

We measured the radiographic inclination angles of 200 consecutive uncemented primary THAs. In the first 100 the component was introduced freehand and in the second 100 a digital protractor was used to measure the operative inclination angle.

The mean difference between the operative and the radiographic inclination angles (∆RI–OI) in the second cohort was 12.3° (3.8° to 19.8°). There was a strong correlation between the circumference of the hip and ∆RI–OI. The number of RI outliers was significantly reduced in the protractor group (p = 0.002).

Adjusting the OI, using a digital protractor and taking into account the circumference of the patient’s hip, improves the RI significantly (p < 0.001) and does not require additional operating time.

Cite this article: Bone Joint J 2015; 97-B:603–610.

The cam-type deformity in femoroacetabular impingement is a 3D deformity. Single measurements using radiographs, CT or MRI may not provide a true estimate of the magnitude of the deformity. We performed an analysis of the size and location of measurements of the alpha angle (α°) using a CT technique which could be applied to the 3D reconstructions of the hip. Analysis was undertaken in 42 patients (57 hips; 24 men and 18 women; mean age 38 years (16 to 58)) who had symptoms of femoroacetabular impingement related to a cam-type abnormality. An α° of > 50° was considered a significant indicator of cam-type impingement. Measurements of the α° were made at different points around the femoral head/neck junction at intervals of 30°: starting at the nine o’clock (posterior), ten, eleven and twelve o’clock (superior), one, two and ending at three o’clock (anterior) position.

The mean maximum increased α° was 64.6° (50.8° to 86°). The two o’clock position was the most common point to find an increased α° (53 hips; 93%), followed by one o’clock (48 hips; 84%). The largest α° for each hip was found most frequently at the two o’clock position (46%), followed by the one o’clock position (39%). Generally, raised α angles extend over three segments of the clock face.

Single measurements of the α°, whether pre- or post-operative, should be viewed with caution as they may not be representative of the true size of the deformity and not define whether adequate correction has been achieved following surgery.

Cite this article: Bone Joint J 2014;96-B:1167–71.

The outcome after total hip replacement has improved with the development of surgical techniques, better pain management and the introduction of enhanced recovery pathways. These pathways require a multidisciplinary team to manage pre-operative education, multimodal pain control and accelerated rehabilitation. The current economic climate and restricted budgets favour brief hospitalisation while minimising costs. This has put considerable pressure on hospitals to combine excellent results, early functional recovery and shorter admissions.

In this review we present an evidence-based summary of some common interventions and methods, including pre-operative patient education, pre-emptive analgesia, local infiltration analgesia, pre-operative nutrition, the use of pulsed electromagnetic fields, peri-operative rehabilitation, wound dressings, different surgical techniques, minimally invasive surgery and fast-track joint replacement units.

Cite this article: Bone Joint J 2013;95-B:1587–94.

The aim of this review is to evaluate the current available literature evidencing on peri-articular hip endoscopy (the third compartment). A comprehensive approach has been set on reports dealing with endoscopic surgery for recalcitrant trochanteric bursitis, snapping hip (or coxa-saltans; external and internal), gluteus medius and minimus tears and endoscopy (or arthroscopy) after total hip arthroplasty. This information can be used to trigger further research, innovation and education in extra-articular hip endoscopy.

Objectives

The purpose of this study was to assess N-acetyl aspartate changes in the thalamus in patients with osteoarthritis of the hip using proton magnetic resonance spectroscopy.