Despite the high success rate of primary total hip replacement (THR), a significant early revision rate remains, which is largely attributed to instability and dislocations. Despite the implants being placed according to the safe zone philosophy of Lewinnek, occurrence of THR dislocation is not an uncommon complication. Large diagnostic and computational model studies have shown variability in patients’ mobility based on the individual anatomic and functional relationship of the hip–pelvis–spine complex. The absolute and relative position of hip replacement components changes throughout motion of the patient’s body. In the case of spinopelvic pathology such as spine stiffness, the system reaches abnormal positional states, as shown with computerized models. The clinical result of such pathologic hip positioning is edge loading, implant impingement, or even joint dislocation. To prevent such complications, surgeons must change the dogma of single correct implant positioning and take into account patients’ individualized anatomy and function. It is essential to broaden the standard diagnostics and their anatomical interpretation, and correct the pre-operative surgical planning. The need for correct and personalized implant placement pushes forward the development and adaptation of novel technologies in THR, such as robotics. In this current concepts narrative review, we simplify the spinopelvic biomechanics and pathoanatomy, the relevant anatomical terminology, and the diagnosis and management algorithms most commonly used today.

Introduction: Mini-invasive surgical (MIS) approaches to total hip replacement (THR) are becoming more popular and increasingly adapted into practice. THR via the direct anterior approach (MIS DAA) has become a rather controversial topic in hip arthroplasty literature in the last decades. Our retrospective observational study focuses on the prevalence of one approach-specific complication—lateral femoral cutaneous nerve (LFCN) iatrogenic lesion—and tries to clarify the possible pathogenesis of this injury. Methods: This is a retrospective single-cohort observational single-center and single-surgeon study. Our patient records were searched for the period from 2015 to 2017—after a safe period of time after the learning curve for MIS DAA. All intra- and post-operative lesions of the LFCN were recorded. Lesion of the LFCN was confirmed by a neurological examination. Minimum patient follow-up was 2 years. Results: This study involved 417 patients undergoing single-side THR via MIS DAA. Patients were examined on follow-up visits at 6 weeks, 6 months, 1 year, and 2 years after surgery. There were 17 cases of LCFN injury at the 6 weeks early follow-up visit (4.1%). All cases of clinically presenting LFCN injury resolved at the 2-year follow-up ad integrum. Discussion: Possible explanations of such neurological complications are direct iatrogenic injury, vigorous traction, hyperextension, or extreme external rotation of the operated limb. Use of a traction table or concomitant spinal pathology and deformity also play a role. Prevention involves stepwise adaptation of the approach during the learning curve period by attending cadaver lab courses, rational use of traction and hyperextension, and careful surgical technique in the superficial and deep fascial layers. Dynamometers could be used to visualise the limits of manipulation of the operated limb. Conclusions: Neurological complications are not as rare but questionably significant in patients undergoing THR via the DAA. Incidental finding of LFCN injury has no effect on the functional outcome of the artificial joint. It can lead to lower subjective satisfaction of patients with the operation, which can be avoided with careful education and management of expectations of the patients.

Objectives: Total hip arthroplasty (THA) is increasingly performed in younger men, many of whom regard sexual function as an important component of postoperative quality of life. Regular sexual activity contributes to overall well-being. Hip osteoarthritis (OA) impairs sexual activity in up to 70% of patients, and THA may restore it and improve sexual quality of life. Although the direct anterior approach (DAA) has been associated with faster recovery, its influence on patient-centred outcomes such as sexual health remains insufficiently studied. To our knowledge, erectile function after THA has not been compared between surgical approaches. Methods: In this prospective multicentre cohort study, 87 sexually active men aged 18–65 years underwent primary THA via either DAA ( n = 49) or the anterolateral approach (ALA; n = 38). Outcomes were assessed preoperatively and 6 months postoperatively using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC; pain, stiffness, function), the World Health Organization Quality of Life-BREF (WHOQOL-BREF; physical and psychological domains), and the International Index of Erectile Function-5 (IIEF-5). Data were analysed using two-way mixed-design ANOVAs. Results: Both groups demonstrated significant postoperative improvements in pain, stiffness, physical function, and quality of life. Compared with the ALA group, the DAA group had lower postoperative pain and greater reduction in stiffness (both p < .001). Erectile function improved significantly in the DAA group ( p < .001), whereas no significant change was observed in the ALA group. Conversely, the ALA group showed greater improvements in physical well-being ( p = .049) and psychological well-being ( p < .001). Conclusions: Both approaches improved function and quality of life after THA. DAA was associated with greater reductions in pain and stiffness and may confer an additional benefit in erectile function, whereas ALA was associated with greater perceived gains in overall well-being. Larger studies with more comparable cohorts are warranted.