2-Year Radiostereometric Analysis Evaluation of a Short, Proximally Coated, Triple-Taper Blade Femoral Stem Versus a Quadrangular-Taper Stem With Reinforced Proximal Body: A Randomized Controlled Trial.

BACKGROUND: Cementless stem designs with proximal metaphyseal fixation aim to achieve better load distribution, reduce stress shielding, and improve primary stability. The purpose of this prospective, randomized controlled trial was to evaluate the 2-year migration and clinical outcomes of two cementless femoral stems. METHODS: A total of 60 participants undergoing primary total hip arthroplasty for any cause were randomly allocated to receiving either a proximally coated, short blade stem or a quadrangular-taper stem with a reinforced proximal body. Radiostereometric analysis radiographs were performed postoperatively and at 6 weeks, 6 months, 1 year and 2 years. The Harris Hip Score, Oxford Hip Score and the EuroQol five-dimension were also collected. RESULTS: At two years, the median subsidence of the short-blade stem was 0.097 millimeters (mm) [Interquartile range (IQR) -0.67 to 0.08)] versus 0.086 mm(IQR, -0.29 to 0.005, P = .683); medial translation 0.023 mm (IQR 0.08 to 0.12) versus 0.029 mm(IQR -0.07 to 0.10, P = .907); anterior translation 0.035 mm (IQR -0.23 to 0.33) versus 0.07 mm (IQR -0.13 to 0.08, P = .268). At 24 months postoperatively, there were no stem revisions and Patient-Reported Outcome Measures (PROMs) were comparable between groups. CONCLUSION: Both cementless stems exhibited a predictable migration pattern and achieved initial stability. There was no difference in migration across the three Cartesian axes at any time point. Clinical outcomes and PROMs were also comparable. Biological fixation of both implants evidenced by the radiostereometric analysis and excellent PROMs are likely to translate to longer-term stability, which would need to be corroborated by longer-term outcome studies.

Functional Component Positioning in Total Hip Arthroplasty and the Role of Robotic-Arm Assistance in Addressing Spinopelvic Pathology.

Hip, spine, and pelvis function as a unified kinetic chain. Any spinal pathology, results in compensatory changes in the other components to accommodate for the reduced spinopelvic motion. The complex relationship between spinopelvic mobility and component positioning in total hip arthroplasty presents a challenge in achieving functional implant positioning. Patients with spinal pathology, especially those with stiff spines and little change in sacral slope, are at high instability risk. In this challenging subgroup, robotic-arm assistance enables the execution of a patient specific plan, avoiding impingement and maximizing range of motion; especially utilizing virtual range of motion to dynamically assess impingement.

Image-based robotic-assisted total hip arthroplasty through direct anterior approach allows a better orientation of the acetabular cup and a better restitution of the centre of rotation than a conventional procedure.

PURPOSE: The aim was to investigate the contribution of robotics assisted total hip arthroplasty (THA) through direct anterior approach (DAA) in improving radiographic precision, functional results and complications. METHODS: This retrospective study compared 100 primary conventional THA (cTHA) to 50 primary robotic THA (rTHA) through DAA. All cups were placed with the objective of having no anterior overhang while respecting the safe zones (SZ). Radiographic analysis included cup inclination and anteversion, vertical and horizontal changes of the rotation centre (ΔVCOR, ΔHCOR), acetabular and femoral offset. SZ were 30-50° of inclination and 10-30° of anteversion. Outliers were defined as medial displacement of the COR > 5 mm, vertical displacement of the COR > 3 mm superiorly. Harris hip score (HHS) and complications were compared at one year of follow-up. RESULTS: The robotic cups were better oriented with 98% in the global SZ versus 68% in the cTHA group (p = 0.0002). The COR was on average better restored in the robotic group in both the horizontal and vertical planes (Δ HCOR = - 5.0 ± 5.0 vs - 3.4 ± 4.9, p = 0.03; Δ VCOR = 1.6 ± 3.3 vs 0.2 ± 2.7, p = 0.04). There were fewer outliers in the rTHA group concerning VCOR (28% versus 10%, p = 0.03). There was no significant difference in HHS and complication rate at one year. CONCLUSION: The use of robotics for THA by DAA provided an advantage in controlling the orientation of the cup and the restoration of its rotation centre. Thanks to the 3D planning on CT scan, it allowed to respect the thresholds while avoiding the anterior overhangs.

Getting Research Published and Achieving the Highest Impact Factor.

High-quality surgical clinical trials are fundamental to the delivery of evidence-based orthopaedics; however, fewer than 1% of patients who undergo surgery worldwide are enrolled in surgical clinical trials. Advances in orthopaedic surgery depend on the creativity and innovation of researchers who investigate, develop, and execute local, national, and international surgical clinical trials, all of which will ultimately affect surgical practice and patient care. Surgeons should understand the challenges of surgical clinical trials, including identifying important research questions; getting support for ideas; establishing clinical research networks; collecting, collating, and analyzing data; as well as getting research published and achieving the highest impact factor. Surgeons also should understand how research material should be formatted and presented in a manuscript that is submitted for publication as well as the elements an editor seeks in a research manuscript.

Cementless hip implants: an expanding choice.

INTRODUCTION: Total hip replacement is a successful procedure with long survival records compared to other joint arthroplasties. Cemented implants have been available for many years, however the complications associated with loosening and, ultimately, failure over time has led to the development of cementless stems and implants.The ideal prosthesis should recreate a biomechanically normal hip joint, allow pain-free function and last the patient's life span without requiring revision. Optimal results with uncemented femoral stems rely on obtaining initial stability, osseointegration, biological fixation, and uniform stress transfer to the proximal bone.There are a multitude of factors that can affect the integration, stability and fixation of these stems into bone, and understanding these factors is the key to choosing the appropriate implant for a specific femur. METHODS: This article aims to discuss cementless prostheses based on evidence-based practice. Geometry, roughness, stem coating, technique and bone quality are among the factors discussed. This was achieved through a review of the current literature. CONCLUSIONS: Uncemented femoral stems have shown good, long-term survivorship and functional outcome, with promising results in younger patients.Limitations in the current literature make it difficult to assess and compare different designs to determine optimal indications for each type.Biological fixation, in which the prosthesis is directly fixed to the bone, is the preferred fixation method.Future studies of cementless implants should consistently address patient age, activity level, bone type, and deformities so that more definitive conclusions can be drawn about when to use each design.

Pyomyositis of the piriformis muscle presenting with sciatica in a teenage rugby player.

The authors report a rare case of piriformis pyomyositis, in a teenage rugby player, who was initially feverish and presented to us with low back pain, sciatica and inability to mobilise due to pain. Subsequent imaging investigations (MRI scan) revealed abscess formation in the piriformis muscle with compression effect on the ipsilateral sciatic nerve. A course of intravenous antibiotic therapy followed by oral antibiotics fully resolved his symptoms and returned inflammatory markers back to normal.