• The purpose of this systematic literature review is to analyse the role of the iliofemoral ligament (ILFL) as a hip joint stabilizer in the current literature.

• A total of 26 articles were included in the review. The ILFL is the largest hip ligament consisting of two distinct arms and is highly variable, both in its location and overall size, and plays a primary role in hip stability; in the case of hip dislocation, the iliofemoral ligament tear does not heal, resulting in a persistent anterior capsule defect. Clinically, the ILFL is felt to limit external rotation in flexion and both internal and external rotation in extension.

• The abduction–hyperextension–external rotation (AB-HEER) test is overall the most accurate test to detect ILFL lesions. Injuries of the ILFL could be iatrogenic or a consequence of traumatic hip instability, and can be accurately studied with magnetic resonance imaging. Different arthroscopic and open techniques have been described in order to preserve the ILFL during surgery and, in case of lesions, several procedures with good to excellent results have been reported in the existing literature.

• The current systematic review, focusing only on the ILFL of the hip, summarizes the existing knowledge on anatomy, imaging and function and contributes to the further understanding of the ILFL, confirming its key role in anterior hip stability. Future studies will have to develop clinical tests to evaluate the functionality and stability of the ILFL.

Cite this article: EFORT Open Rev 2021;6:545-555. DOI: 10.1302/2058-5241.6.200112

• Preoperative evaluation of the pathomorphology is crucial for surgical planning, including radiographs as the basic modality and magnetic resonance imaging (MRI) and case-based additional imaging (e.g. 3D-CT, abduction views).

• Hip arthroscopy (HAS) has undergone tremendous technical advances, an immense increase in use and the indications are getting wider. The most common indications for revision arthroscopy are labral tears and residual femoroacetabular impingement (FAI).

• Treatment of borderline developmental dysplastic hip is currently a subject of controversy. It is paramount to understand the underlining problem of the individual hip and distinguish instability (dysplasia) from FAI, as the appropriate treatment for unstable hips is periacetabular osteotomy (PAO) and for FAI arthroscopic impingement surgery.

• PAO with a concomitant cam resection is associated with a higher survival rate compared to PAO alone for the treatment of hip dysplasia. Further, the challenge for the surgeon is the balance between over- and undercorrection.

• Femoral torsion abnormalities should be evaluated and evaluation of femoral rotational osteotomy for these patients should be incorporated to the treatment plan.

Cite this article: EFORT Open Rev 2021;6:472-486. DOI: 10.1302/2058-5241.6.210019

• Pelvic discontinuity (PD) has been a considerable challenge for the hip revision arthroplasty surgeon. However, not all PDs are the same. Some occur during primary cup insertion, resembling a fresh periprosthetic fracture that separates the superior and inferior portions of the pelvis, while others are chronic as a result of gradual acetabular bone loss due to osteolysis and/or acetabular implant loosening.

• In the past, ORIF, various types of cages, bone grafts and bone cement were utilized with little success. Today, the biomechanics and biology of PD as well as new diagnostic tools and especially a variety of new implants and techniques are available to hip revision surgeons. Ultraporous cups and augments, cup-cage constructs and custom triflange components have revolutionized the treatment of PD when used in various combinations with ORIF and bone grafts. For chronic PD the cup-cage construct is the most popular method of reconstruction with good medium-term results.

• Dislocation continues to be the leading cause of failure in all situations, followed by infection. Ultimately, surgeons today have a big enough armamentarium to select the best treatment approach. Case individualization, personal experience and improvisation are the best assets to drive treatment decisions and strategies.

Cite this article: EFORT Open Rev 2021;6:459-471. DOI: 10.1302/2058-5241.6.210022

• Most meta-diaphyseal femoral fractures that are treated with intramedullary nailing can be reduced satisfactorily by skeletal traction without ‘opening’ the fracture site and therefore, complications such as nonunion, infection and wound healing problems are reduced.

• In cases where adequate fracture reduction cannot be achieved by skeletal traction, ‘reduction aids’ have been used during the operative procedure in order to avoid the exposure of the fracture site.

• The ‘blocking’ screw, as a reduction tool, was proposed initially for the ‘difficult’ metaphyseal fractures of the tibia. Subsequently, surgeons have tried to implement the ‘blocking’ screw technique in ‘difficult’ distal femoral fractures.

• This article presents the ‘blocking’ screw technique as an adjunctive process in the management of fractures of the proximal and distal femur which are found to be non-reducible by skeletal traction alone. The minimal invasiveness of the technique contributes greatly to the preservation of both the soft tissue integrity and the fracture haematoma and thus reduces the major complications that can occur by exposing the fracture site.

Cite this article: EFORT Open Rev 2021;6:451-458. DOI: 10.1302/2058-5241.6.210024

• Modular dual-mobility (MDM) constructs can be used to reduce dislocation rates after total hip replacement (THR). However, there are concerns about adverse reaction to metal debris (ARMD) as a result of fretting corrosion between the metal liner and shell. This systematic review reports outcomes following THR using MDM components. It was registered with PROSPERO and conducted in line with Cochrane and PRISMA recommendations.

• Sixteen articles were included overall, with meta-analysis performed on relevant subsets using a random intercept logistic regression model. Estimated median incidence of ARMD requiring revision surgery within study follow-up period was 0.3% (95% CI 0.1 – 1.8%, from 11 cohort studies containing 1312 cases).

• Serum metal ion levels were mildly raised in 7.9% of cases, and significantly raised in 1.8%, but there was no correlation with worse clinical hip function scores within studies. Dislocation rate was 0.8%. Revision rate was 3.3%.

• There are mixed reports of wear on the backside of the metal liner from the acetabular shell and screw heads. Both implant design and component malseating are implicated, but currently it is unclear to what extent each factor is responsible.

• Studies were poor quality with high risk of confounding, especially from trunnion corrosion. We have made recommendations for further work. In the meantime, surgeons should be aware of the potential risk of ARMD when considering using an MDM prosthesis, and, if selecting one, must ensure proper seating of the liner and screws intraoperatively.

Cite this article: EFORT Open Rev 2021;6:343-353. DOI: 10.1302/2058-5241.6.200146

• The literature was reviewed to establish the levels of stem subsidence for both double and triple-tapered implants in order to determine whether there were any differences in subsidence levels with regard to the methods of measurement, the magnitude and rate of subsidence and clinical outcomes.

• All studies reporting subsidence of polished taper-slip stems were identified. Patient demographics, implant design, radiological findings, details of surgical technique, methods of measurement and levels of subsidence were collected to investigate which factors were related to increased subsidence.

• Following application of inclusion and exclusion criteria, 28 papers of relevance were identified. The studies initially recruited 3090 hips with 2099 being available for radiological analysis at final follow-up. Patient age averaged 68 years (42–70), 60.4% were female and the average body mass index (BMI) was 27.4 kg/m² (24.1–29.2).

• Mean subsidence at one, two, five and 10 years was 0.97 mm, 1.07 mm, 1.47 mm and 1.61 mm respectively. Although double-tapered stems subsided more than triple-tapered stems at all time points this was not statistically significant (p > 0.05), nor was the method of measurement used (p > 0.05).

• We report the levels of subsidence at which clinical outcomes and survivorship remain excellent, but based on the literature it was not possible to determine a threshold of subsidence beyond which failure was more likely.

• There were relatively few studies of triple-tapered stems, but given that there were no statistically significant differences, the levels presented in this review can be applied to both double and triple-tapered designs.

Cite this article: EFORT Open Rev 2021;6:331-342. DOI: 10.1302/2058-5241.6.200086

• Treatment of bacterial septic arthritis in the native adult hip joint can be challenging. Prompt diagnosis and treatment decisions can reduce the associated morbidity and mortality.

• For this systematic review of the literature, we asked: (1) What are the treatment options? (2) What are the success rates and the outcomes after treatment? (3) Which antibiotic and duration of therapy are optimal?

• We searched the electronic databases PubMed, Scopus, and Embase using the search terms “hip” or “native hip” and “septic arthritis” or “coxitis”. Studies were included if they reported on: (1) bacterial infection of the hip, (2) treatment, (3) success rate/outcomes, (4) follow-up. The final review included 19 studies. The quality of study reporting was evaluated with the Methodological Index for Non-randomized Studies (MINORS) questionnaire.

• Three treatment options are: arthroscopy, single open surgery, and two-stage total hip arthroplasty (THA). A high success rate in infection eradication was reported for all three. Intravenous antibiotic therapy should be promptly initiated to eradicate septic arthritis and minimize potential sequelae and complications.

• Arthroscopy, single open or two-stage THA were reported to be effective in treating bacterial septic arthritis of the native hip. The key to optimal outcome is early diagnosis and timely treatment.

Cite this article: EFORT Open Rev 2021;6:164-172. DOI: 10.1302/2058-5241.6.200082

• The aging of our society is associated with an increasing number of insufficiency fractures of the pelvis and the current standard of care is pain control and early mobilization. The aim of this study was to explore whether parathyroid hormone (PTH) treatment can support bone healing in these patients.

• We conducted a systematic review searching the databases PubMed, Embase and Cochrane. Our primary outcome was fracture healing, secondary outcome measures comprised pain, mobility and patient-reported outcome measures (PROMs).

• Eight articles were included in the qualitative synthesis, of which two were included in a meta-analysis. However, only three studies were comparative including one randomized controlled trial. Fracture healing and reported pain were assessed after eight weeks, and were significantly improved in the group being treated with PTH (p < 0.01) in the meta-analysis. All articles described a positive effect for PTH on fracture healing and pain.

• Our systematic review indicates that there is a positive effect of PTH treatment on healing and pain in patients with insufficiency fracture in the pelvic ring, but further research is necessary.

Cite this article: EFORT Open Rev 2021;6:9-14. DOI: 10.1302/2058-5241.6.200029

• When introducing an implant, surgeons are subjected to steep learning curves, which may lead to a heightened revision rate. Stepwise introduction revolutionized implant introduction but lacks a last step.

• No guidelines exist for the introduction of a well-documented implant not previously used in a department. This is problematic according to the European Union’s legislated tendering process, potentially leading to increased revisions. In this systematic review, the introduction of a well-documented total hip arthroplasty implant to experienced surgeons is explored amid concerns of higher revision rate.

• Literature search strategies were deployed in the Embase and Medline databases, revealing a total of 14,612 articles. Using the Covidence software (Cochrane, London), two reviewers screened articles for inclusion.

• No articles were found that fulfilled our eligibility criteria. A post hoc analysis retrieved two national register-based studies only missing information about the surgeon’s knowledge of the introduced implant. None of the introduced implants decreased the revision rate and around 30% of the introduced implants were associated with a higher revision rate.

• The review showed that no data exist about revision rates when introducing well-documented implants. In continuation thereof, the introduction of well-documented implants might also be associated with increased revision rates, as has been shown for total knee arthroplasty. We therefore suggest that special attention should be focused on changes of implants in departments, which can be achieved by way of specific registration in national registers.

Cite this article: EFORT Open Rev 2021;6:3-8. DOI: 10.1302/2058-5241.6.200047

• Parkinson’s disease (PD) poses a significant challenge for the arthroplasty surgeon, owing to excessive muscle tone, higher fracture risk and poor bone quality. Several studies have reported high mortality, early failure and perioperative complications associated with hip fracture surgery in PD; however, no higher-level evidence exists regarding elective hip arthroplasty.

• The aim of our study was to perform a systematic review to evaluate the evidence basis and clinical outcomes pertaining to patients with underlying Parkinson’s disease undergoing elective total hip arthroplasty (THA).

• We searched MEDLINE, EMBASE and The Cochrane Central Register of Controlled Trials to identify studies evaluating the safety and clinical outcomes of THA in patients suffering from Parkinson’s. Our review conforms to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

• Ten studies encompassing 49,730 patients were included in our systematic review. Qualitative synthesis demonstrated comparable results between PD patients and controls with respect to one-year mortality and surgical site infections. PD patients experienced more medical complications, had a longer hospital stay and worse long-term implant survival. Some studies also reported a higher rate of dislocation, periprosthetic fractures and aseptic loosening.

• Decisions about the optimal articulation, the utilization of cemented components, dual-mobility cups or constrained liners were not uniform among included studies.

• THA in patients with Parkinson’s disease can offer significant functional gains and pain relief. Surgical considerations pertain to the approach and ways to address instability, whereas emphasis should be placed on appropriate counselling and exploring whether potential improvement of life quality outweighs the risks.

Cite this article: EFORT Open Rev 2020;5:856-865. DOI: 10.1302/2058-5241.5.200034