Orthopedic Surgeons’ Accuracy When Orienting an Acetabular Cup. A Comparison with Untrained Individuals

Background and Objectives: Previous studies demonstrated a huge variability among surgeons when it comes to reproducing the position of an acetabular cup in total hip arthroplasty. Our main objective is to determine if orthopedic surgeons can replicate a given orientation on a pelvic model better than untrained individuals. Our secondary objective is to determine if experience has any influence on their ability for this task. Materials and Methods: A group of specialist orthopedic hip surgeons and a group of volunteers with no medical training were asked to reproduce three given (randomly generated) acetabular cup orientations (inclination and anteversion) on a pelvic model. Error was measured by means of a hip navigation system and comparisons between groups were made using the appropriate statistical methods. Results: The study included 107 individuals, 36 orthopedic surgeons and 71 untrained volunteers. The mean error among surgeons was slightly greater as regards both inclination (7.84 ± 5.53 vs. 6.70 ± 4.03) and anteversion (5.85 ± 4.52 vs. 5.48 ± 3.44), although statistical significance was not reached (p = 0.226 and p = 0.639, respectively). Similarly, although surgeons with more than 100 procedures a year obtained better results than those with less surgical experience (8.01 vs. 7.67 degrees of error in inclination and 5.83 vs. 5.87 in anteversion), this difference was not statistically significant, either (p = 0.852 and p = 0.981). Conclusions: No differences were found in the average error made by orthopedic surgeons and untrained individuals. Furthermore, the surgeons’ cup orientation accuracy was not seen to improve significantly with experience.

Stromal cells of giant cell tumor of bone show primary cilia in giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a locally aggressive primary bone neoplasm composed by tumoral stromal cells (SCs) and a reactive component that consists of monocytic/histiocytic cells that give rise by fusion to osteoclast-like multinucleated cells. Recently, specific Histone 3.3 mutations have been demonstrated in SCs of GCTB. Many of the pathways related to bone proliferation and regulation depend on the primary cilium, a microtubule-based organelle that protrudes outside the cell and acts as a sensorial antenna. In the present work, we aimed to study the presence and role of primary cilia in GCTB. Ultrastructural, immunohistochemical, and immunofluorescence studies were performed in order to demonstrate, for the first time, that the primary cilium is located in spindle-shaped SCs of GCTB. Moreover, we showed Hedgehog (Hh) signaling pathway activation in these cells. Hence, primary cilia may play a relevant role in GCTB tumorogenesis through Hh signaling activation in SCs. RESEARCH HIGHLIGHTS: Transmission electron microscopy allows describing and differentiating cellular subpopulations in giant cell tumor of bone (GCTB). The primary cilium is present in some tumoral stromal cells of GCTB. Hedgehog signalling is activated in these cells.

Hip fracture in centenarians, what can we expect?

INTRODUCTION

Hip fractures in centenarians are rising due to the increase in life expectancy. The objective of this study is to compare the characteristics of centenarians' hip fracture with a younger control group, and to analyze whether there are differences in terms of in-hospital mortality, complications, and short-medium-term survival between them.

MATERIAL AND METHODS

Retrospective case-control study, with a series of 24 centenarians and 48 octogenarians with a hip fracture. Comorbidities and Charlson index, surgical delay, complications and mortality during admission, and hospital stay were analyzed. At discharge, early mortality, survival after one year, and return to previous functionality were assessed.

RESULTS

No significant differences were found in baseline parameters or comorbidities (P>.05), and the type of was a woman with an extracapsular fracture. Hospital stay was longer in the control group (P=.038), and the most frequent complication was anemia requiring transfusion (23/24 in centenarians, P<.0001). In-hospital mortality and accumulated at one year in the centenarians was 33 and 67%, respectively, compared to 10 and 25% in the octogenarians (P=.017, OR=4.3 [1,224-15,101] and P=.110). Only 2 centenarian patients were able to walk again after the intervention, while in the control group 53.84% returned to the previous functional situation (P=.003).

CONCLUSIONS

Compared to a control group of younger patients, in-hospital mortality and in the first year after a hip fracture is significantly higher in centenarians, and very few recover activity prior to the fracture.

Biomechanical behavior of retrograde intramedullary nails in distal femoral fractures

Fractures of the distal femur affect three different groups of individuals: younger people suffering high-energy trauma, elderly people with fragile bones and people with periprosthetic fractures around previous total knee arthroplasty. Main indications of intramedullary nailing are for supracondylar fractures type A or type C of the AO classification. The main objective of the present work is to analyze, by means of FE simulation, the influence of retrograde nail length, considering different blocking configurations and fracture gaps, on the biomechanical behavior of supracondylar fractures of A type. A three dimensional (3D) finite element model of the femur from 55-year-old male donor was developed, and then a stability analysis was performed for the fixation provided by the retrograde nail at a distal fracture with different fracture gaps: 0.5 mm, 3 mm y 20 mm, respectively. Besides, for each gap, three nail lengths were studied with a general extent (320 mm, 280 mm and 240 mm), considering two transversal screws (M/L) at the distal part and different screw combinations above the fracture. The study was focused on the immediately post-operative stage, without any biological healing process. In view of the obtained results, it has been demonstrated new possibilities of blocking configuration in addition to the usual ones, which allows establishing recommendations for nail design and clinical practice, avoiding excessive stress concentrations both in screws, with the problem of rupture and loss of blocking, and in the contact of nail tip with cortical bone, with the problem of a new stress fracture.

Primary total hip arthroplasty for acetabular fractures in elderly patients

INTRODUCTION

Life expectancy has risen, leading to an increase in acetabular fractures in fragile patients. Total hip arthroplasty with a reinforcement cage is a technically complex option, but allows fracture control and early mobilization. Our aim is to assess whether the use of Burch-Schneider cage in fragile patients with acetabular fractures allows immediate load stabilization without threatening the early survival of the arthroplasty.

MATERIAL AND METHODS

Descriptive study of a series of 14 patients with acetabular fractures treated by a reinforcement cage associated with autologous bonegraft plus a cemented acetabular cup, and mobilization and bearing. Judet Letournel fracture types, surgical delay, and complications during admission were analyzed. Following hospital discharge we recorded the incorporation of grafts according to Gie's classification, presence of calcifications according to Brooker, consolidation of the fracture, loosening of implants and functional aspects according to the HHS and Merlé D'Aubigné Postel score.

RESULTS

The most common fracture was both columns (6/14), with a surgical delay being of 11 days mean and 21,5 days of length of stay. One patient died after surgery. The mean follow-up was 34.4 months. All fractures healed and the bonegraft was incorporated in all cases. The mean HHS was 82 points and the Merle Score was 15/18. There were no complications related to arthroplasty.

CONCLUSIONS

Total hip arthroplasty with Burch-Schneider cage on bonegraft and no added osteosynthesis is a good option of treatment of all types of displaced acetabular fractures in a fragile patient.

International trauma care: initial European approaches during the COVID 19 pandemic

The world was not prepared for the global of pandemic in early 2020 with the arrival of COVID 19. Europe has some of the most developed health care systems in the world and this article explains the initial response to the pandemic from an orthopaedic and trauma viewpoint from 8 nations. Italy reported the first cluster in February, which then rapidly spread around the continent, requiring a rapid reorganization of services. The reports highlight how elective surgery was universally stopped, surgical services were reconfigured, and new practices, such as the widespread use of telemedicine, may well become permanent. It also emphasizes how the pandemic has re-educated us on the importance of a consistent and central approach to deal with a global health crisis, and how medical services need to remain flexible and responsive to new ways of working.

Biomechanical Behavior of an Hydroxyapatite-Coated Traditional Hip Stem and a Short One of Similar Design: Comparative Study Using Finite Element Analysis

Background

The objective is to compare, by the means of finite elements analysis, the biomechanical behavior of a conventional stem of proven performance with a short stem based on the same fixation principles.

Methods

A 3D femur was modeled from CT scan data, and real bone density measures were incorporated into it. Load stresses were applied to that bone in 3 different scenarios: without prosthesis, with the conventional stem, and with the short stem. Different bone loading patterns were compared by Gruen’s zones both visually and statistically using Welch’s test.

Results

The implantation of a stem generates a certain degree of stress shielding in the surrounding bone, but the pattern of the change is very similar in the compared stem models. Although there is statistical significance (P < 0.01) in the mean stress variation in most of the Gruen’s zones, the magnitude of the difference is always under 2 MPa (range: 0.01 – 1.74 MPa).

Conclusions

The bone loading patterns of the traditional stem and the short stem are very similar. Although there is no evidence of a link between biomechanics and clinical outcomes, our results may suggest that theoretical advantages of short stems can be exploited without the fear of altering bone loading patterns.

Is the mortality higher in patients who have suffered a hip fracture?

BACKGROUND AND OBJECTIVE

The aim of this study is to value whether patients who have suffered a hip fracture have a higher mortality than expected.

MATERIAL AND METHODS

A prospective, observational study was carried out where patients with hip fracture were collected as a sample over a year. The study included 284 patients and a minimum follow-up was 2 years. The mean age of these patients was 84.26 years, with 21.48% (61/284) males and 78.5% (223/284) females. Survival and previous diseases that affect mortality, as risk factors, were collected and analyzed using the Kaplan-Meier method and the Cox regression model. Actual mortality was compared with that expected according to the Charlson Comorbidity Index, adjusted for age.

RESULTS

Previous pathology was the main mortality factor, with heart disease being the most significant (OR 1.817, CI95%: 1.048; 3.149). The real mortality at one year of the sample was 22.5%, while the estimated annual mortality according to the Charlson Comorbidity Index was 29.68% (CI95%:44,36-15).

CONCLUSIONS

Hip fracture does not cause an increase in mortality according to the Charlson Comorbidity Index estimate.

Revision total knee arthroplasty: hybrid vs standard cemented fixation

Introduction

Modular systems with stems are necessary for the stability of revision total knee arthroplasty (rTKA), but controversy remains as to the best fixation method: cemented or hybrid (noncemented stem). The aim of this study was to assess the clinical, X-ray, life-quality and survival results obtained with each fixation method.

Materials and methods

During the period 2000–2013, rTKA was performed on 67 patients (29 cemented arthroplasty and 38 hybrid fixation). The average follow-up was 7 years (range 2–15). All patients were evaluated clinically and radiographically using the American Knee Society Score (AKSS), the Western Ontario and McMaster Universities Arthritis Index (WOMAC), and the Short Form Health Survey (SF-36). A survival study was performed via Kaplan–Meier analysis.

Results

There were no differences between the cemented and hybrid fixation groups in the preoperative and postoperative AKSS clinical evaluation indices and the SF-36 health index. However, the WOMAC assessment scale did reveal statistically significant differences between the groups, with a global classification of 64.9 points weighted at 100 (SD 16.8) for cemented fixation versus 78.9 (SD 9.0) for hybrid fixation (p = 0.001). The corresponding values for stiffness were 61.6 (SD 12.9) and 80.5 (SD 14.7) (p = 0.001), and those for function were 61.3 (SD 19.4) and 78.1 (SD 10.5) (p = 0.001). No significant differences between the groups were recorded with respect to the pain score (p = 0.4) or the results of the Kaplan–Meier survival analysis.

Conclusion

Although the results were similar for the two groups, hybrid fixation tended to produce better results than cemented fixation. In view of the risk of further loosening, we prefer the more conservative approach, i.e. hybrid fixation.

Level evidence

Level III.

Metacarpal Enlargement of the Amputated Thumb using Callotaxis: An Observational Study

Purpose To confirm the effectiveness of bone elongation through callus distraction of the first metacarpal as a functional alternative in active patients with a thumb amputation.

Methods The study population consisted of patients who suffered a nonreplantable amputation of the thumb and failed to meet the criteria for a microsurgical transfer at our hospitals between 1995 and 2014. We performed an observational cohort study for the incidence analysis and a cross-sectional design for the analysis of the correlations among the variables.

Results We presented 23 callus distractions of the first metacarpal, with an elongation time between surgeries of approximately 104.7 days (standard deviation [SD]: 3.2), with a miniRail external mini-fixator, and an average elongation of 25.5 mm (SD: 0.54). All patients achieved a functional grip, but five of them had to find new jobs. The degree of satisfaction was high, except in two patients, and was significantly related to the time of the elongation.

Conclusions Callus distraction allows for a reconstruction of the thumb with few complications. We recommend associating it with a commissuroplasty and an adductor transposition. Patients give more importance to the comfort of the procedure than to the elongated length, provided that adequate function is achieved.

[Prognosis factors in carpal tunnel syndrome surgery]

INTRODUCTION

Carpal tunnel syndrome is the most frequent peripheral neuropathy and it affects nearly 3% of the general population. Although electromyography tests have become the gold standard for diagnosis, currently there is controversy between the correlation of clinical data and electromyography for diagnosis. The purpose of this work is to study this correlation and determine the possible prognostic factors in this pathology.

MATERIAL AND METHODS

139 patients who underwent surgery were reviewed retrospectively between January 1995 and December 2008. All patients had an electromyography preoperatively to obtain motor conduction rate and latency, sensitive conduction rate and clinical examination, especially the Tinel and Phalen signs in order to correlate them with the final postoperative symptoms. In order to establish if there were statistically significant differences, these were determined through the T-Student and chi2.

RESULTS

Preoperatively, there is a clinical correlation (p < 0.05) between the Tinel and Phanel clinical signs with the compression electrophysiological grading. Likewise, there is a correlation between clinical persistence in the postoperative period with motor conduction rate and latency involvement specified in the preoperative electrophysiological tests.

CONCLUSION

Electrophysiological tests in the diagnosis of carpal tunnel syndrome have an added prognostic value with regards to the final result after surgery.