Groin pain is a frequent cause of discomfort in patients and highly prevalent in active patients. One of the diagnoses causing groin pain is femoroacetabular impingement (FAI). However, the incidence of FAI in the general population is unknown. This study aimed to identify the incidence of groin pain suggestive of FAI in a cohort of 31 451 patients in the Netherlands during 1 year. A cooperation of 16 general practitioners (GPs) participated in this prospective registry. All GPs were educated in the clinical manifestation of FAI and the physical examination for FAI. Patients of all ages were registered when presenting with ‘groin pain’. Between July 2013 and July 2014, 84 patients aged between 15 and 60 years of age presented with groin pain, reflecting an incidence of 0.44%. Of these patients, 17% (14 patients) were radiologically diagnosed with FAI. Another 30% of these patients had a high clinical suspicion for FAI. This is the first report on the incidence of groin pain suggestive of FAI in a general population diagnosed by GPs. Of all 84 patients presenting with groin pain, 17% were diagnosed with FAI. Creating awareness of FAI in GPs helps identifying patients that might benefit from FAI treatment.

PurposeTo report risk factors, 1-year and overall risk for a contralateral hip and other osteoporosis-related fractures in a hip fracture population.MethodsAn observational study on 1,229 consecutive patients of 50 years and older, who sustained a hip fracture between January 2005 and June 2009. Fractures were scored retrospectively for 2005–2008 and prospectively for 2008–2009. Rates of a contralateral hip and other osteoporosis-related fractures were compared between patients with and without a history of a fracture. Previous fractures, gender, age and ASA classification were analysed as possible risk factors.ResultsThe absolute risk for a contralateral hip fracture was 13.8 %, for one or more osteoporosis-related fracture(s) 28.6 %. First-, second- and third-year risk for a second hip fracture was 2, 1 and 0 %. Median (IQR) interval between both hip fractures was 18.5 (26.6) months. One-year incidence of other fractures was 6 %. Only age was a risk factor for a contralateral hip fracture, hazard ratio (HR) 1.02 (1.006–1.042, p = 0.008). Patients with a history of a fracture (33.1 %) did not have a higher incidence of fractures during follow-up (16.7 %) than patients without fractures in their history (14 %). HR for a contralateral hip fracture for the fracture versus the non-fracture group was 1.29 (0.75–2.23, p = 0.360).ConclusionThe absolute risk of a contralateral hip fracture after a hip fracture is 13.8 %, the 1-year risk was 2 %, with a short interval between the 2 hip fractures. Age was a risk factor for sustaining a contralateral hip fracture; a fracture in history was not.

BackgroundFemoroacetabular impingement (FAI) is caused by an anatomic deviation of the acetabular rim or proximal femur, which causes chronic groin pain. Radiological identification of FAI can be challenging. Advances in imaging techniques with the use of computed tomography (CT) scan enable 3D simulation of FAI. We made an experimental cadaveric validation study to validate the 3D simulation imaging software.MethodsThe range of motion (ROM) of five cadaveric hips was measured using an electromagnetic tracking system (EMTS). Specific marked spots in the femur and pelvis were created as reproducible EMTS registration points. Reproducible motions were measured. Hips were subsequently imaged using high-resolution CT after introduction of artificial cam deformities. A proprietary software tool was used, Articulis (Clinical Graphics) to simulate the ROM during the presence and absence of the induced cam deformities.ResultsAccording to the EMTS, 13 of the 30 measured ROM end-points were restricted by > 5° due to the induced cam deformities. Using Articulis, with the same 5° threshold, we correctly detected 12 of these 13 end point limitations and detected no false positives. The median error of the measured limitations was 1.9° (interquartile range 1.1° - 4.4°). The maximum absolute error was 5.4°.ConclusionsThe use of this dynamic simulation software to determine the presence of motion limiting deformities of the femoroacetabular is validated. The simulation software is able to non-invasively detect a reduction in achievable ROM, caused by a cam type deformity.

BackgroundHip arthroscopic treatment is not equally beneficial for every patient undergoing this procedure. Therefore, the purpose of this study was to develop a clinical prediction model for functional outcome after surgery based on preoperative factors.MethodsProspective data was collected on a cohort of 205 patients having undergone hip arthroscopy between 2011 and 2015. Demographic and clinical variables and patient reported outcome (PRO) scores were collected, and considered as potential predictors. Successful outcome was defined as either a Hip Outcome Score (HOS)-ADL score of over 80% or improvement of 23%, defined by the minimal clinical important difference, 1 year after surgery. The prediction model was developed using backward logistic regression. Regression coefficients were converted into an easy to use prediction rule.ResultsThe analysis included 203 patients, of which 74% had a successful outcome. Female gender (OR: 0.37 (95% CI 0.17–0.83); p = 0.02), pincer impingement (OR: 0.47 (95% CI 0.21–1.09); p = 0.08), labral tear (OR: 0.46 (95% CI 0.20–1.06); p = 0.07), HOS-ADL score (IQR OR: 2.01 (95% CI 0.99–4.08); p = 0.05), WHOQOL physical (IQR OR: 0.43 (95% CI 0.22–0.87); p = 0.02) and WHOQOL psychological (IQR OR: 2.40 (95% CI 1.38–4.18); p = < 0.01) were factors in the final prediction model of successful functional outcome 1 year after hip arthroscopy. The model’s discriminating accuracy turned out to be fair, as 71% (95% CI: 64–80%) of the patients were classified correctly.ConclusionsThe developed prediction model can predict the functional outcome of patients that are considered for a hip arthroscopic intervention, containing six easy accessible preoperative risk factors. The model can be further improved trough external validation and/or adding additional potential predictors.

Objectives: Traction force widens the joint space during hip arthroscopy. It is unclear how much the traction force varies and if it is related to the joint space widening. Main goal of our study was to measure the amount of force needed to widen the hip joint. Second goal was to study the relation between this force and the amount of joint space widening. Methods: Traction force was measured in 27 patients (of whom 24 female, mean age 41) during arthroscopy. Measurements were performed before the procedure, after vacuum seal release and after capsulotomy. Joint space widening was measured with fluoroscopy and was calibrated. Friedman and Wilcoxon tests were used to measure differences in traction. The Spearman’s rho correlation coefficient was used to identify a correlation in traction force and joint space widening. Regression analyses were used to identify relations between age, body mass index (BMI), hip degeneration and traction force. Results: The median traction force before arthroscopy was 714 N, lowered to 520 N after vacuum seal release and to 473 N after capsulotomy ( p < 0.001). Median joint space widening was 8.8 mm. Spearmans’ rho correlation between traction force and joint space widening was ‒0.13. Discussion: Median traction force of 714 N resulted in 8.8 mm of joint space widening. This traction force was significantly lowered by 200 N after release of the vacuum seal of the hip and 250 N after additional capsulotomy without loss of joint space narrowing. No significant relation was identified for age, BMI or progression of the Kellgren-Lawrence classification for hip degeneration and traction force. Netherlands Trial Registry number 8610

Background: Cam and pincer-type morphologies can cause femoroacetabular impingement syndrome (FAI) and can be measured on plain radiographs using the alpha angle and the center edge angle. As an addition to plain radiographs and to assess femoroacetabular impingement, it is possible to visualize the interplay of the acetabular and femoral morphology by means of dynamic three-dimensional simulation of hip joint. Therefore, the objective of this study is to compare alpha angles and center edge angles on plain radiographs with the dynamic computerized tomography (CT) analysis in patients with complaints of femoroacetabular impingement. Methods: All patients from our prospective cohort from 2012 to 2015 who underwent radiographs and a dynamic CT analysis for FAI were selected. Cam type morphologies were measured with the alpha angle and pincer type morphologies with lateral center-edge angle on radiographs and with CT analysis. The dynamic CT analysis also calculated position and size of impingement of femur and acetabulum. Intra-operative assessment was used to confirm impingement. Sensitivity, specificity and predictive values were calculated compared with respect to the intra-operative assessment. Results: A total of 127 patients were included. 90 cam morphologies and 45 pincer morphologies were identified intra-operatively. The sensitivity and specificity for cam morphology measured with radiographs was 84 and 72% compared to 90 and 43% with three dimensional dynamic analyses. The sensitivity and specificity for pincer morphology measured with radiographs was 82 and 39% compared to 84 and 51% with three dimensional dynamic analyses. Conclusions: Diagnostic accuracy is comparable in three-dimensional dynamic analysis of CT scans and radiographs representing FAI caused by cam or pincer type morphology.

The RIA system has benefits in the treatment of nonunion and osteomyelitis defect, but is not without risk. Meticulous surgical technique is mandatory and peroperative constant monitoring of patients and the assembled device is mandatory.

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