Introduction: Shorter, anatomically shaped and proximally loading stems have been developed to achieve better stress distribution and be more bone preserving. The purpose of this prospective study was to evaluate the migration pattern of the Proxima™ ultra-short uncemented stem using radiostereometric analysis (RSA), and to review the literature regarding the migration of short stemmed hip arthroplasty. Methods: 25 patients (28 hips) with hip osteoarthritis received a Proxima stem during total hip arthroplasty (THA). To measure stem migration, repeated RSA examinations were done during a 2 year follow up period. The patients were evaluated with the hip specific (HOOS) and the generic health (EQ5D) scores up to 1 year, and clinically for 6 years postoperatively. Results: Almost all migration occurred within the first 3 months, with mean subsidence of 0.22 mm and varus rotation of 1.04°, being the primary effect variables. After the third postoperative month and up to the 2 year RSA follow up no further significant migration occurred. The outcome scores showed substantial improvement after 1 year. No revisions were performed or indicated for any stem after a mean clinical follow up of 72.1 months. Conclusions: Like many other uncemented stems, the Proxima showed early migration up to 3 months hereafter osseointegration seems to have occurred. The achieved stability and clinical outcomes indicate favorable early results for this stem in younger patients who have good bone quality and average BMI. We found, however, the surgical technique to be slightly more demanding compared to conventional stems owing to the unique implant design that necessitates specific adjusted femoral cutting and broaching procedures.

Background/Objectives: Acetabular erosion is a postoperative condition that can occur after hip hemiarthroplasty (HA), potentially leading to pain and requiring conversion to total hip arthroplasty (THA). Given the discrepancy in its incidence and impact in the literature, this study aims to report the incidence of symptomatic acetabular erosion and the subsequent conversion to THA in all HA cases performed in a single health system. Methods: A total of 2477 HA cases had their clinical notes and serial radiographs examined for this retrospective study. Outcome measures included any records of hip or groin pain and conversion to THA that were attributed to acetabular erosion as documented in the clinical notes. Results: Two thousand four hundred and seventy-seven HA cases were reviewed in this study. The mean age for all patients in the study was 81.5 years and the mean follow up was 3.7 years. Out of the 2477 HA cases, only 12 HA cases (0.48%) in 12 patients had data records of chronic hip pain, attributable to acetabular wear in the clinical notes, of variable severity and presentations. The mean duration until the clinical documentation of acetabular wear-induced pain was 25.6 months (range, 1.4–146.4 months), with most symptomatic hip erosion cases presented within the first year (50% presented within the first 6 months) after the index HA surgery. Despite that, only five cases underwent conversion to THA (0.2%) while seven patients received conservative management. Conclusions: In patients older than 65 years of age who are candidates for HA, the incidence of symptomatic hip erosion and the subsequent conversion to THA is low and hence HA remains a viable treatment option. Based on the duration until clinical presentation of acetabular erosion, this study suggests that the state of acetabular cartilage during surgery may influence the development of early acetabular wear in most symptomatic patients. On the other hand, hip hemiarthroplasty is a rare treatment option for displaced femoral neck fractures in patients younger than 65 years of age, and its use in this patient subset depends on conditional and patient-related factors such as the activity level, cognitive function, and medical comorbidities.

Effect of lengthening along the anatomical axis of the femur and its clinical impact

Knee osteoarthritis is categorized classically as a non-inflammatory arthropathy. However, there has been increasing evidence regarding the supplementary role of inflammation in the pathogenesis and disease progression of knee osteoarthritis. This study aims to identify a potential correlation between synovial fluid white blood cell (SF WBC) count and the severity of knee osteoarthritis clinical presentation. 200 knees (200 patients) were assessed through SF aspiration and cytology analysis for WBC count. All patients have filled out the Knee Injury and Osteoarthritis Outcome Score for clinical correlation. For the 200 knees, there was a statistically significant positive correlation between the severity of osteoarthritis clinical presentation as expressed by the Knee Injury and Osteoarthritis Outcomes Score (KOOS) and the synovial white blood cell count among the studied cases (p-value < 0.001). There was no statistically significant correlation found between the patient's age, sex, or side and KOOS or SF white cell count. The clinical severity of knee osteoarthritis is directly correlated with increased SF white cell count, and hence, SF WBCs may play a role in identifying and grading osteoarthritis clinical severity. This may raise the interest in identifying the role of using specific disease-modifying drugs that deal with the WBC function in cases of osteoarthritis along with other modalities. Received: 30 April 2024 | Revised: 22 July 2024 | Accepted: 12 September 2024 Conflicts of Interest The authors declare that they have no conflicts of interest to this work. Data Availability Statement The data that support this work are available upon reasonable request to the corresponding author. Author Contribution Statement Hesham El-khodary: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation. Ahmed Nageeb Mahmoud: Software, Writing - original draft, Writing - review & editing, Visualization. Daniel S. Horwitz: Writing - review & editing, Visualization. Elzaher Hassan Elzaher: Resources, Writing - review & editing, Visualization. Mostafa Aly Elabd: Software, Resources, Writing - review & editing. Mariia Sovalkina: Software, Formal analysis. Ahmed Samy Kamel: Conceptualization, Methodology, Investigation, Resources, Data curation, Supervision, Project administration. Ahmed Mohasseb: Conceptualization, Methodology, Validation, Formal analysis, Investigation, Resources, Data curation, Supervision, Project administration.