No Difference in Patient-Reported Outcomes for Periacetabular Osteotomy and Hip Arthroscopy With Capsular Plication in the Setting of Borderline Hip Dysplasia: A Propensity-Matched Multicenter Study With Minimum 5-Year Follow-Up.

PURPOSE: To compare minimum 5-year patient-reported outcome measures after hip arthroscopy (HA) and periacetabular osteotomy (PAO) for borderline hip dysplasia. METHODS: Hips with a lateral center-edge angle (LCEA) between 18° and less than 25° that underwent either PAO or HA were selected from 2 institutions. The exclusion criteria were as follows: LCEA less than 18°, Tönnis osteoarthritis grade greater than 1, prior hip surgical procedures, active inflammatory disease, Workers' Compensation, and concomitant surgery. Patients underwent propensity matching based on age, sex, body mass index, and Tönnis osteoarthritis grade. Patient-reported outcome measures included the modified Harris Hip Score, as well as calculation of the minimal clinically important difference, patient acceptable symptom state, and maximum outcome improvement satisfaction threshold. Preoperative radiographic predictors included comparison of the Femoro-epiphyseal Acetabular Roof index and ligamentum teres lesions. RESULTS: A total of 28 PAO patients underwent propensity matching to 49 HA patients. The 2 groups were similar in terms of mean age, sex, preoperative body mass index, and LCEA. The PAO group had a longer mean follow-up period (95.8 months vs 81.3 months, P = .001). The mean Femoro-epiphyseal Acetabular Roof index was significantly lower preoperatively in the HA group (P < .001). The 2 groups showed similar and significant improvements in the mean modified Harris Hip Score from preoperatively to latest follow-up (P < .001). The relative risk of subsequent surgery in the PAO group was 3.49 (P = .024), mostly attributed to hardware removal (25%). The revision rate was 3.6% in the PAO group and 8.2% in the HA group (P = .65). One patient in the PAO group required revision HA for intra-articular adhesions. Three of the patients requiring revision in the HA group underwent PAO because of persistent pain, and one underwent revision HA alone. Conversion to total hip arthroplasty was required in 1 patient in the HA group and no patients in the PAO group. CONCLUSIONS: Both PAO and HA with capsular plication provide borderline hip dysplasia patients with clinically significant improvements and low revision rates at a minimum of 5 years postoperatively. LEVEL OF EVIDENCE: Level III, retrospective, comparative therapeutic trial.

Augmented reality-guided pelvic osteotomy of Ganz: feasibility in cadavers.

INTRODUCTION: The periacetabular osteotomy is a technically demanding procedure with the goal to improve the osseous containment of the femoral head. The options for controlled execution of the osteotomies and verification of the acetabular reorientation are limited. With the assistance of augmented reality, new possibilities are emerging to guide this intervention. However, the scientific knowledge regarding AR navigation for PAO is sparse. METHODS: In this cadaveric study, we wanted to find out, if the execution of this complex procedure is feasible with AR guidance, quantify the accuracy of the execution of the three-dimensional plan, and find out what has to be done to proceed to real surgery. Therefore, an AR guidance for the PAO was developed and applied on 14 human hip cadavers. The guidance included performance of the four osteotomies and reorientation of the acetabular fragment. The osteotomy starting points, the orientation of the osteotomy planes, as well as the reorientation of the acetabular fragment were compared to the 3D planning. RESULTS: The mean 3D distance between planned and performed starting points was between 9 and 17 mm. The mean angle between planned and performed osteotomies was between 6° and 7°. The mean reorientation error between the planned and performed rotation of the acetabular fragment was between 2° and 11°. CONCLUSION: The planned correction can be achieved with promising accuracy and without serious errors. Further steps for a translation from the cadaver to the patient have been identified and must be addressed in future work.

Total hip arthroplasty through the direct anterior approach for sequelae of Legg-Calvé-Perthes disease.

INTRODUCTION: Due to multiplanar deformities of the hip, total hip arthroplasty (THA) for sequelae of Legg-Calvé-Perthes disease (LCPD) is often technically demanding. This study aimed to compare the clinical and radiographic outcomes of patients with sequelae of LCPD undergoing THA through the direct anterior approach (DAA) and non-anterior approaches to the hip. METHODS: All patients with sequelae of LCPD who underwent primary THA between 2004 and 2018 (minimum follow-up: 2 years) were evaluated and separated into two groups: THA through the DAA (Group AA), or THA through non-anterior approaches to the hip (Group non-AA). Furthermore, a consecutive control group of patients undergoing unilateral THA through the DAA for primary hip osteoarthritis (Group CC) was retrospectively reviewed for comparison. RESULTS: Group AA comprises 14 hips, group non-AA 17 hips and group CC 30 hips. Mean follow-up was 8.6 (± 5.2; 2-15), 9.0 (± 4.6; 3-17) and 8.1 (± 2.2; 5-12) years, respectively. At latest follow-up, Harris Hip Score was 90 (± 20; 26-100), 84 (± 15; 57-100), and 95 (± 9; 63-100) points, respectively. Overall, 6 patients treated for LCPD (each 3 patient in the AA and non-AA group) developed postoperative sciatic nerve palsy, of which only one was permanent. Complication-related revision rate at the latest follow-up was 15% in the AA-group and 25% in the non-AA group, respectively. CONCLUSION: THA through the DAA might be a credible option for the treatment of sequelae of LCPD with comparable complication rates and functional outcomes to non-anterior approaches.

Combining the advantages of 3-D and 2-D templating of total hip arthroplasty using a new tin-filtered ultra-low-dose CT of the hip with comparable radiation dose to conventional radiographs.

BACKGROUND: Inaccurately scaled radiographs for total hip arthroplasty (THA) templating are a source of error not recognizable to the surgeon and may lead to inaccurate reconstruction and thus revision surgery or litigation. Planning based on computed tomography (CT) scans is more accurate but associated with higher radiation exposure. The aim of this study was (1) to retrospectively assess the scaling deviation of pelvic radiographs; (2) to prospectively assess the feasibility and the radiation dose of THA templating on radiograph-like images reconstructed from a tin-filtered ultra-low-dose CT dataset. METHODS: 120 consecutive patients were retrospectively analyzed to assess the magnification error of our current THA templates. 27 consecutive patients were prospectively enrolled and a radiographic work-up in the supine position including a new tin-filtered ultra-low-dose CT scan protocol was obtained. THA was templated on both images. Radiation dose was calculated. RESULTS: Scaling deviations between preoperative radiographs and CT of ≥ 5% were seen in 25% of the 120 retrospectively analyzed patients. Between the two templates trochanter tip distance differed significantly (Δ2.4 mm, 0-7 mm, p = 0.035)), predicted femoral shaft size/cup size was the same in 45%/41%. The radiation dose of the CT (0.58 mSv, range 0.53-0.64) was remarkably low. CONCLUSION: Scaling deviations of pelvic radiographs for templating THA may lead to planning errors of ≥ 3 mm in 25% and ≥ 6 mm in 2% of the patients. 2-D templating on radiograph-like images based on tin-filtered ultra-low-dose CT eliminates this source of error without increased radiation dose. LEVEL OF EVIDENCE: Retrospective and prospective comparative study, Level III.

Antimicrobial susceptibility testing is crucial when treating Finegoldia magna infections.

Finegoldia magna is an anaerobic gram-positive bacterium that can cause invasive human infections. Recently, a 52-year-old patient suffering from a periprosthetic joint infection (PJI) due to F. magna was treated with cefepime on hemodialysis; however, treatment failed due to relapse caused by antibiotic-resistant strains. Reports on the antimicrobial susceptibility of F. magna clinical isolates are rare. We collected 57 clinical F. magna isolates from Zurich, Switzerland, between September 2019 and July 2020 and tested their antimicrobial susceptibility to investigate the local resistance pattern. Antimicrobial susceptibility testing (AST) was evaluated for nine antibiotics (benzylpenicillin, amoxicillin/clavulanic acid, cefuroxime, cefepime, levofloxacin, rifampicin, metronidazole, doxycycline, and clindamycin) by E-test according to CLSI guidelines. All F. magna strains were susceptible to benzylpenicillin, amoxicillin/clavulanic acid, and metronidazole, while 75% to clindamycin. F. magna isolates showed MIC values lower than species-unrelated breakpoints for cefuroxime, levofloxacin, and cefepime in 93%, 56%, and 32% of the cases, respectively. MIC values for rifampicin and doxycycline were lower than locally determined ECOFFs in 98% and 72% of the cases, respectively. In summary, we recommend the use of benzylpenicillin, amoxicillin/clavulanic acid, or metronidazole without prior AST as first-line treatment option against F. magna PJI infections. If cefuroxime, cefepime, levofloxacin, rifampicin, doxycycline, or clindamycin are used, AST is mandatory.

Acetabular reconstruction with femoral head autograft in primary total hip arthroplasty through a direct anterior approach is a reliable option for patients with secondary osteoarthritis due to developmental dysplasia of the hip.

BACKGROUND: Developmental dysplasia is challenging to treat with total hip arthroplasty via the direct anterior approach (DAA). Reconstructing the former anatomy while restoring the acetabular bone stock for future revisions in this young patient collective combined with the known advantages of the DAA would be desirable. The purpose of this study was to analyze the feasibility, radiographic outcome and clinical outcome of primary uncemented total hip arthroplasty with bulk femoral head autograft for acetabular augmentation through a DAA with a minimal follow-up of 12 months. METHODS: A retrospective, consecutive series from March 2006 to March 2018 of 29 primary total hip arthroplasty with acetabular augmentation with bulk femoral head autograft through a direct anterior approach was identified. All complications, reoperations and failures were analyzed. Radiographic and clinical outcome was measured. RESULTS: 24 patients (29 hips) with a mean age of 43 (18-75) years and a mean follow-up of 35 months (12-137) were included. Surgical indication was secondary osteoarthritis for developmental dysplasia of the hip (Hartofilakidis Grade A (n = 19), B (n = 10)) in all cases. We noted no conversion of the approach, no dislocation and no acetabular loosening. The center of rotation was significantly distalized by a mean of 9 mm (0-23) and significantly medialized by a mean of 18 mm (6-29). The bone graft was fully integrated after 12 months in all cases. CONCLUSION: Acetabular reconstruction with femoral head autograft in primary THA through a direct anterior approach seems to be a reliable option for the treatment of secondary osteoarthritis in patients with DDH Hartofilakidis grade A and B. Prospective cohort studies with a large sample population and a long-term follow-up are necessary to confirm our findings.

External snapping hip syndrome is associated with an increased femoral offset.

BACKGROUND: External snapping hip syndrome (ESH) is postulated to be one of the causes of greater trochanteric pain syndrome, which also includes greater trochanteric bursitis and tendinopathy or tears of the hip abductor mechanism. However, it was not yet described what kind of bony morphology can cause the snapping and whether symptomatic and asymptomatic individuals have different imaging features. PURPOSE: It was the purpose of this study to look for predisposing morphological factors for ESH and to differentiate between painful and asymptomatic snapping. METHODS: A consecutive cohort with ESH and available magnetic resonance imaging (MRI) between 2014 and 2019 was identified. The control group consisted of patients that underwent corrective osteotomies around the knee for mechanical axis correction and never complained of hip symptoms nor had undergone previous hip procedures. The following parameters were blindly assessed for determination of risk factors for ESH: CCD (corpus collum diaphysis) angle; femoral and global offset; femoral antetorsion; functional femoral antetorsion; translation of the greater trochanter (GT); posterior tilt of the GT; pelvic width/anterior pelvic length; intertrochanteric width. Hip and pelvic offset indexes were calculated as ratios of femoral/global offset and intertrochanteric/pelvic width, respectively. For the comparison of symptomatic and asymptomatic snapping, the following soft-tissue signs were investigated: presence of trochanteric bursitis or gluteal tendinopathy; presence of surface bony irregularities on trochanter major and ITB (Iliotibial band) thickness. RESULTS: A total of 31 hips with ESH were identified. The control group (n = 29) consisted of patients matched on both age (± 1) and gender. Multiple regression analysis determined an increased hip offset index to be independent predictor of ESH (r = + 0.283, p = 0.025), most likely due to the higher femoral offset in the ESH group (p = 0.031). Pearson correlation analysis could not identify any significant secondary factors. No differences were found between painful and asymptomatic snapping on MRI. CONCLUSIONS: A high hip offset index was found as an independent predictor for external snapping hip in our cohort, mainly due to increased femoral offset. No imaging soft-tissue related differences could be outlined between symptomatic and asymptomatic external snapping. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00590 .

Lack of Conclusive Evidence of the Benefit of Biologic Augmentation in Core Decompression for Nontraumatic Osteonecrosis of the Femoral Head: A Systematic Review.

PURPOSE: To assess whether biologic augmentation in addition to core decompression (CD), compared with CD alone, improves clinical and radiographic outcomes in the treatment of nontraumatic osteonecrosis of the femoral head (ONFH). Our hypothesis was that biologic augmentation would reduce the progression of osteonecrosis and therefore also the rate of conversion to total hip arthroplasty (THA). METHODS: A systematic review was performed in accordance with the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) statement. Six databases were searched: Central, MEDLINE, Embase, Scopus, AMED, and Web of Science. Studies comparing outcomes of CD versus CD plus biologic augmentation (with or without structural augmentation), with a reported minimum level of evidence of III and ≥24 months of follow-up, were eligible. Procedural success was conceptualized as (1) avoidance of conversion to THA and (2) absence of radiographic disease progression. Risk of bias was assessed using the Joanna Briggs Institute critical appraisal checklists. A quantitative analysis of heterogeneity was undertaken. RESULTS: We included studies reporting on 560 hips in 484 patients. Biologic augmentation consisted of bone marrow stem cells in 10 studies, bone morphogenic protein in 2, and platelet-rich plasma in 1. Three studies used additional structural augmentation. The median maximum follow-up time was 45 months. Only 4 studies reported improvement in all clinical scores in the augmentation group. Seven studies observed a reduction in the rate of radiographic progression, and only 5 found reduced rates of conversion to THA when using augmentation. A high risk of bias and marked heterogeneity was found, with uncertainty about the study designs implemented, analytical approaches, and quality of reporting. CONCLUSION: Current evidence is inconclusive regarding the benefit of biologic augmentation in CD for nontraumatic ONFH, because of inconsistent results with substantial heterogeneity and high risk of bias. LEVEL OF EVIDENCE: III, systematic review of level I, II, and III studies.

Factors affecting outcome in the treatment of streptococcal periprosthetic joint infections: results from a single-centre retrospective cohort study.

PURPOSE: To report and analyse factors affecting the outcome of streptococcal periprosthetic joint infections (PJIs). METHODS: A retrospective analysis of consecutive streptococcal PJIs was performed. Musculoskeletal Infection Society 2013 criteria were used. Outcome was compared with a prospective PJI cohort from the same institution. RESULTS: The most common isolated streptococcal species was Streptococcus dysgalactiae (9/22, 41%) among 22 patients included. Surgical treatment consisted of DAIR (debridement, antibiotics, irrigation and retention) in 12 (55%), one-stage revision arthroplasty in one (4%), two-stage revision arthroplasty in eight (37%) and implant removal in one (4%) patient. An infection free-outcome was achieved in 15 cases (68%), whilst seven (32%) patients failed initial revision and relapsed with the same pathogen, from which six were treated with DAIR and one with one-stage revision arthroplasty. No failures were observed in patients who received a two-stage revision. Failure rates did not differ in the cases treated with rifampin (1/5) from those without 6/17 (p = 0.55). There was no correlation between the length of antibiotic treatment and relapse (p = 0.723). In all failures, a persistent distant infection focus was identified at the time of relapse. Compared with our prospective PJI cohort, relapse rates were significantly higher 32% vs 12% (p < 0.05). CONCLUSION: No correlation with the use of rifampin or length of antibiotic treatment was found. No failures were observed in patients who received a two-stage revision, which may be the surgical treatment of choice. A distant persisting infection focus could be the reason for PJI relapse with recurrent hematogenous seeding in the joint.

FAI morphology increases the risk for osteoarthritis in young people with a minimum follow-up of 25 years.

INTRODUCTION: The mechanical conflict in symptomatic femoroacetabular impingement can lead to early osteoarthritis. However, radiographic impingement morphology is often seen in asymptomatic individuals. Long-term observation regarding the risk of developing osteoarthritis in these individuals is lacking. Our study addressed the following questions: Does femoroacetabular impingement morphology increase the risk for development of osteoarthritis after at least 25 years? If yes, which radiographic parameter is the most predictive? Does the level of activity influence the risk for development of osteoarthritis? Are PROM influenced by the grade of osteoarthritis in this population? METHODS: We investigated 51 (32 male, 19 female) patients for whom AP pelvis and Dunn view radiographs were available with a minimum follow-up of 25 years. Alpha angle in AP pelvis and Dunn view radiographs, femoral torsion in Dunn view, lateral center edge angle, cross-over sign, posterior wall sign and prominence of ischial spine sign in AP pelvis radiographs were determined. On the follow-up radiographs, osteoarthritis was graded. Tegner Score for the time of the index radiograph was evaluated. Harris Hip Score and Western Ontario and McMaster Universities Osteoarthritis Index were assessed at latest follow-up. RESULTS: The mean follow-up was 43 years (range 25-58). Cam impingement morphology showed to increase the risk for development of osteoarthritis: Alpha angles of ≥ 55° on AP pelvis and Dunn view radiographs were associated risk factors and showed an OR of 1.05 (p = 0.002) and 1.10 (p = 0.001), respectively. Abnormal femoral torsion and acetabular retroversion were not risk factors for osteoarthritis. Tegner Score at index presentation, HHS and WOMAC Score did not correlate with the grade of osteoarthritis. CONCLUSION: This study showed that cam impingement morphology in young patients raises the risk for development of hip osteoarthritis by 5-10% in a long-term follow-up with a minimum of 25 years, thus its contribution was small.

Revision rate of THA in patients younger than 40 years depends on primary diagnosis - a retrospective analysis with a minimum follow-up of 10 years.

BACKGROUND: Treating osteoarthritis in elderly patients with THA is very successful. However, surgeons hesitate to recommend THA in younger patients. The spectrum of etiologies for end stage hip disease in the younger population is diverse and therefore different courses may be assumed. Our objective was to evaluate THA revision rate within a minimum follow-up period of 10 years in young patients and to analyze the difference between different primary diagnoses. METHODS: We included 144 consecutive hips in 127 patients younger than 40 years, who received a primary THA from 01/1996 to 12/2007. Operative reports, clinical and radiographic documentation were reviewed to determine primary diagnosis, prior hip surgery, component specifications and revision surgery. 111 hips in 97 patients were available for outcome analysis with a minimum follow-up of 10 years. RESULTS: The mean age was 33 years (range 15-40 years) at the time of the index THA, 68 patients were female and 59 were male. Ten years revision rate on the prosthetic components was 13%. The most common primary diagnosis was DDH. DDH was associated with a risk of 17% for requiring a reoperation on the prosthetic components because of mechanical fatigue and therefore, significantly higher than for any other primary diagnosis (p = 0.005). CONCLUSION: THA in young patients is associated with a high revision rate of 13% in 10 years. 17% of patients with DDH required revision surgery for mechanical fatigue within 10 years, which was significantly higher than for any other primary diagnosis (1.2%, OR 16.8).

Diagnosis of Periprosthetic Hip Joint Infection Using MRI with Metal Artifact Reduction at 1.5 T.

Background MRI with metal artifact reduction has gained importance in assessment of pain with total hip arthroplasty (THA). However, its role in diagnosis of periprosthetic joint infection (PJI) has not been well defined. Purpose To evaluate findings of PJI after THA and to determine the diagnostic performance of 1.5-T MRI with metal artifact reduction. Materials and Methods Dedicated compressed sensing-based slice encoding for metal artifact correction 1.5-T MRI examinations (from January 2015 to April 2018) in patients with THA PJI (infection group) and noninfected THA (control group) were retrospectively evaluated by two musculoskeletal radiologists. Fisher exact test was used to compare the groups. Sensitivity, specificity, and accuracy were evaluated for each finding. Interobserver reliability was assessed with κ statistics. Results Forty patients (mean age, 69 years ± 11 [standard deviation]; 26 men) in the infection group and 100 patients (mean age, 67 years ± 11; 42 men) in the control group were evaluated. Periosteal reaction, capsule edema, and intramuscular edema differed between the two groups (P < .001 for each finding). Periosteal reaction was found in 31 of 40 patients with infection and 10 of 100 participants in the control group (sensitivity, 78%; specificity, 90%; accuracy, 86%); capsule edema was found in 33 of 40 (infection group) and five of 100 (control group) (sensitivity, 83%; specificity, 95%; accuracy, 91%); and intramuscular edema was found in 38 of 40 (infection group) and 14 of 100 (control group) (sensitivity, 95%; specificity, 86%; accuracy, 89%). Interobserver agreement was almost perfect, with κ values between 0.88 and 0.92. No difference between the two groups was found regarding the presence of osteolysis (infection group, 23 of 40; control group, 60 of 100), bone marrow edema (39 of 40 vs 87 of 100), effusion (20 of 40 vs 26 of 100), abductor tendon lesion (22 of 40 vs 62 of 100), or bursitis (14 of 40 vs 34 of 100) (P > .05 for each finding). Conclusion The presence of periosteal reaction, capsule edema, and intramuscular edema after total hip arthroplasty at 1.5-T MRI with metal artifact reduction had a high accuracy in evaluation of periprosthetic joint infection. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Zanetti in this issue.

The impact of mal-angulated femoral rotational osteotomies on mechanical leg axis: a computer simulation model.

BACKGROUND: Subtrochanteric or supracondylar femoral rotational osteotomies are established surgical treatments for femoral rotational deformities. Unintended change of the mechanical leg axis is an identified problem. Different attempts exist to plan a correct osteotomy plane, but implementation of the preoperative planning into the surgical situation can be challenging. Goal of this study was to identify the critical threshold of mal-angulation of the osteotomy plane and of femoral rotation that leads to a relevant deviation of the postoperative mechanical leg axis using a computer simulation approach. METHODS: Three-dimensional (3D) surface models of the lower extremity of two patients (Model 1: 42° femoral antetorsion; Model 2: 6° femoral retrotorsion) were generated from computed tomography data. First, baseline subtrochanteric and supracondylar rotational osteotomies, perpendicular to the femoral mechanical axis were simulated. Afterwards, mal-angulated osteotomies in sagittal and frontal plane followed by different degrees of rotation were simulated and frontal mechanical axis was analyzed. RESULTS: 400 mal-angulated osteotomies have been simulated. Mal-angulation of ±30° with 30° rotation showed maximum deviation from preoperative mechanical axis in subtrochanteric osteotomies (4.0° ± 0.4°) and in supracondylar osteotomies (12.4° ± 0.8°). Minimal mal-angulation of 15° in sagittal plane in subtrochanteric osteotomies and mal-angulation of 10° in sagittal plane in supracondylar osteotomies altered the mechanical axis by > 2°. Mal-angulation in sagittal plane showed higher deviations of the mechanical axis (up to 12.4° ± 0.8°), than in frontal plane mal-angulation (up to 4.0° ± 1.9°). CONCLUSION: A femoral rotational osteotomy, perpendicular to the femoral mechanical axis, has no considerable influence on the mechanical leg axis. However, mal-angulation of femoral rotational osteotomies showed relevant changes of the mechanical leg axis. In supracondylar respectively subtrochanteric procedures, mal-angulation of only 10° in combination with already 15° of femoral rotation respectively mal-angulation of 15° in combination with 30° of femoral rotation, can lead to a relevant postoperative mechanical leg axis deviation of more than 2°, wherefore these patients probably would benefit from the use of navigation aids.

Three days of training with a low-fidelity arthroscopy triangulation simulator box improves task performance in a virtual reality high-fidelity virtual knee arthroscopy simulator.

PURPOSE: The aim of this work is to evaluate the effectiveness of training with the low-fidelity ArthroBox® regarding performance of different basic arthroscopy tasks using a validated high-fidelity virtual reality simulator of the knee. METHODS: Nineteen volunteers (14 females and 5 males) without any previous experience in arthroscopy were randomly assigned either to the ArthroBox® training group (n =10) or the non-training group (n =9). The training group underwent a supervised ArthroBox ® training consisting of a daily 60-min session for three consecutive days. Both groups completed the basic and the final assessment using a validated virtual reality-based passive haptic knee arthroscopy simulator (ArthroS, VirtaMed™). The following three factors were measured in different exercises (explained in "Materials and methods"): amount of time to finish the task, length of camera and scope path within the joint. Furthermore, the volunteers' demographics (age, sex, dexterity, video game experience, sport activities and profession) was assessed but showed no differences between the groups. RESULTS: There were no significant differences between the training and non-training group regarding the above-mentioned demographic factors. However, the training group showed significant improvement from baseline to follow-up in most activities (e.g. task performance time in seconds, intra-articular camera and grasp distance in centimetres; see Table 1) in comparison to the non-training group. CONCLUSIONS: The results from this study demonstrate that training for three consecutive days using a portable and versatile low-fidelity simulator significantly improves arthroscopy performance when using a validated high-fidelity virtual knee simulator. Arthroscopic triangulation training outside the operating theatre with a portable, low-cost simulator has proven to be a valuable educational tool to improve the arthroscopic skills of trainee surgeons. LEVEL OF EVIDENCE: Diagnostic study, Level II.

Salvage reverse total shoulder arthroplasty for failed operative treatment of proximal humeral fractures in patients younger than 60 years: long-term results.

HYPOTHESIS: Is salvage reverse total shoulder arthroplasty (RTSA) a justifiable treatment for failed operative treatment (open reduction-internal fixation [ORIF] or primary and secondary hemiarthroplasty) of proximal humeral fractures in patients younger than 60 years? METHODS: Thirty patients (mean age, 52 years; age range, 30-59 years) were reviewed after a mean follow-up period of 11 years (range, 8-18 years). Of the patients, 7 (23%) underwent RTSA for failed ORIF and 23 (77%) for failed hemiarthroplasty. Clinical and radiographic outcomes were assessed longitudinally. RESULTS: At final follow-up, the mean relative Constant score had improved from 25% (±12%) to 58% (±21%, P < .001). Significant improvements were seen in the mean Subjective Shoulder Value (20% to 56%), active elevation (45° to 106°), abduction (42° to 99°), pain scores, and strength (P < .001). Clinical outcomes did not significantly deteriorate over a period of 10 years. Patients with salvage RTSA for failed secondary hemiarthroplasty (n = 8) vs. those for failed ORIF (n = 6) showed significantly inferior active abduction (77° vs. 116°, P = .023). Patients with a healed greater tuberosity (n = 9) showed significantly better external rotation than patients with a resorbed/resected greater tuberosity (n = 13, 21° vs. 3°, P = .025). One or more complications occurred in 18 shoulders (60%), and 6 (20%) resulted in explantation of the RTSA. CONCLUSIONS: Salvage RTSA in patients younger than 60 years is associated with a high complication rate. It leads nonetheless to substantial and durable improvement beyond 10 years, provided the complications can be handled with implant retention. Inferior shoulder function is associated with greater tuberosity resorption or resection and inferior overhead elevation with the diagnosis of failed hemiarthroplasty.

Validation of a Virtual Reality-Based Hip Arthroscopy Simulator.

PURPOSE: To assess construct and face validity of a novel virtual reality-based hip arthroscopy simulator using the previously validated Arthroscopic Surgery Skills Evaluation Tool (ASSET), metric parameters, and a questionnaire. METHODS: Metric parameters including task completion time, camera path, and grasper path were recorded, and the ASSET score was used to assess construct validity. Face validity was evaluated using a questionnaire. RESULTS: Nine hip arthroscopy experts, of whom the majority performed more than 200 procedures (age, 48 ± 7.3; range, 38-61 years; 8 men, 1 woman), and 33 nonexperts (age, 33 ± 7.9; range, 26-62 years; 25 men, 8 women) performed 3 individual tasks on a virtual reality-based arthroscopy simulator of a left hip. The ASSET global rating scale showed a statistically significant difference between the hip arthroscopy expert and the nonexpert group, indicating strong construct validity (25.0 in the expert group, range, 17-34, versus 15.30 in the nonexpert group, range, 8-30 [P < .001], respectively). This also applied to most metric parameters recorded by the simulator. The simulator also demonstrated high face validity. The overall impression in terms of realism was graded "completely realistic" by 17% and "close to realistic" by 62% of participants. CONCLUSIONS: The tested simulator demonstrated high construct and face validity. CLINICAL RELEVANCE: This study demonstrates the construct and face validity of a novel hip arthroscopy simulator. The device proved to be an adequate model for the simulation of some arthroscopic procedures of the hip.

Uncemented Total Hip Arthroplasty Through the Direct Anterior Approach: Analysis of a Consecutive Series of 275 Hips With a Minimum Follow-Up of 10 Years.

BACKGROUND: The purpose of this study was to document complications, outcomes, and 10-year survivorship of primary total hip arthroplasty (THA) using a direct anterior approach with an uncemented, straight, hydroxyapatite-coated stem and an uncemented cup. METHODS: A retrospective, consecutive series of 275 primary THAs through a direct anterior approach with traction table using Medacta Versafit cup and Quadra-H stem with a minimum of 10-year follow-up was identified. The cumulative 10-year survival of the implants was estimated using Kaplan-Meier estimator. All complications, reoperations, and failures were analyzed. Subjective and clinical outcomes (Subjective Hip Value, Western Ontario and McMaster Universities Osteoarthritis Index, and Harris Hip Score) were measured. RESULTS: Of 256 patients (275 hips, 143 men and 113 women) with a mean age of 63 (range, 24-85) years, 48 (19%) patients (52 hips) deceased not related to the surgery after a mean time 49 months (range, 3-118) postoperatively. At >10-year follow-up, 9 THAs were revised. The overall implant survival rate was 96.8% (95% confidence interval, 94.4-98.7) at 10 years. One cup and 1 stem were revised because of aseptic loosening. At the last follow-up, the median Subjective Hip Value was 90% (range, 20-100), the Western Ontario and McMaster Universities Osteoarthritis Index score reached a median of 0.2 points (range, 0-6.3), and the median Harris Hip Score points was 99 (range, 29-100). CONCLUSION: Primary THA through an anterior minimal invasive approach with the mentioned implants showed low revision rates and good to excellent clinical outcome after at least 10 years.

Efficacy of standardized training on a virtual reality simulator to advance knee and shoulder arthroscopic motor skills.

BACKGROUND: Most studies demonstrated, that training on a virtual reality based arthroscopy simulator leads to an improvement of technical skills in orthopaedic surgery. However, how long and what kind of training is optimal for young residents is unknown. In this study we tested the efficacy of a standardized, competency based training protocol on a validated virtual reality based knee- and shoulder arthroscopy simulator. METHODS: Twenty residents and five experts in arthroscopy were included. All participants performed a test including knee -and shoulder arthroscopy tasks on a virtual reality knee- and shoulder arthroscopy simulator. The residents had to complete a competency based training program. Thereafter, the previously completed test was retaken. We evaluated the metric data of the simulator using a z-score and the Arthroscopic Surgery Skill Evaluation Tool (ASSET) to assess training effects in residents and performance levels in experts. RESULTS: The residents significantly improved from pre- to post training in the overall z-score: - 9.82 (range, - 20.35 to - 1.64) to - 2.61 (range, - 6.25 to 1.5); p < 0.001. The overall ASSET score improved from 55 (27 to 84) percent to 75 (48 to 92) percent; p < 0.001. The experts, however, achieved a significantly higher z-score in the shoulder tasks (p < 0.001 and a statistically insignificantly higher z-score in the knee tasks with a p = 0.921. The experts mean overall ASSET score (knee and shoulder) was significantly higher in the therapeutic tasks (p < 0.001) compared to the residents post training result. CONCLUSIONS: The use of a competency based simulator training with this specific device for 3-5 h is an effective tool to advance basic arthroscopic skills of resident in training from 0 to 5 years based on simulator measures and simulator based ASSET testing. Therefore, we conclude that this sort of training method appears useful to learn the handling of the camera, basic anatomy and the triangulation with instruments.

Postoperative alignment of TKA in patients with severe preoperative varus or valgus deformity: is there a difference between surgical techniques?

BACKGROUND: There have been conflicting studies published regarding the ability of various total knee arthroplasty (TKA) techniques to correct preoperative deformity. The purpose of this study was to compare the postoperative radiographic alignment in patients with severe preoperative coronal deformity (≥10° varus/valgus) who underwent three different TKA techniques; manual instrumentation (MAN), computer navigated instrumentation (NAV) and patient specific instrumentation (PSI). METHODS: Patients, who received a TKA with a preoperative coronal deformity of ≥10° with available radiographs were included in this retrospective study. The groups were: MAN; n = 54, NAV; n = 52 and PSI; n = 53. The mechanical axis (varus / valgus) and the posterior tibial slope were measured and analysed using standing long leg- and lateral radiographs. RESULTS: The overall mean postoperative varus / valgus deformity was 2.8° (range, 0 to 9.9; SD 2.3) and 2.5° (range, 0 to 14.7; SD 2.3), respectively. The overall outliers (>3°) represented 30.2% (48 /159) of cases and were distributed as followed: MAN group: 31.5%, NAV group: 34.6%, PSI group: 24.4%. No significant statistical differences were found between these groups. The distribution of the severe outliers (>5°) was 14.8% in the MAN group, 23% in the NAV group and 5.6% in the PSI group. The PSI group had significantly (p = 0.0108) fewer severe outliers compared to the NAV group while all other pairs were not statistically significant. CONCLUSIONS: In severe varus / valgus deformity the three surgical techniques demonstrated similar postoperative radiographic alignment. However, in reducing severe outliers (> 5°) and in achieving the planned posterior tibial slope the PSI technique for TKA may be superior to computer navigation and the conventional technique. Further prospective studies are needed to determine which technique is the best regarding reducing outliers in patients with severe preoperative coronal deformity.

Validation of an Arthroscopic Training Device.

PURPOSE: To investigate the usefulness and conduct validation of a simulated arthroscopy training device to train basic arthroscopy skills. METHODS: Forty-six participants including 12 novices, 12 intermediates, and 22 experts completed a questionnaire regarding demographics, previous arthroscopic experience, training potential, and statements about the device. Furthermore, participants performed a single task on the arthroscopic training device using the 0° camera and a probe. The task consisted of an attempt to carry a rubber ring across a helix inside a box as fast as possible. Construct validity was evaluated by comparing total task time and portal replacements of the camera and probe between all groups (median values [interquartile range]; Kruskal-Wallis test). RESULTS: The median age was 35 (29-44) years. There were 4 female and 42 male participants. A total of 89% of the participants graded the overall training capacity ≥5 (35% graded it as 5, 39% as 6, and 15% as 7), and 83% believed that it is useful to improve any kind of arthroscopy. Ninety-three percent of the participants would recommend the arthroscopic training device to their colleagues. Sixty-one percent of the participants stated that there are certain disadvantages. The median time to complete the task was 108 (58-236) seconds. Novices (259 [123-435] seconds) performed tasks significantly slower than intermediates (169 [67-257] seconds) and experts (75 [49-132] seconds) (P = .005). Furthermore, portal changes were significantly more common in novices and intermediates than experts (P = .019). CONCLUSIONS: High scores in training potential were achieved with this arthroscopy simulator box, and most study participants believed that practice with the arthroscopic training device is useful for any kind of arthroscopy. Construct validity was established since novices, intermediates, and experts in real arthroscopy were discriminated with the arthroscopic training device in terms of time to successful completion of a task. However, 61% of the participants stated that there were certain disadvantages. CLINICAL RELEVANCE: In every training tool using simulation, it is crucial to pass the first steps in the validation cascade. This study provides this step for further evaluation of this arthroscopic training device.