Evaluation of changes in radiographic spinopelvic parameters after primary total hip arthroplasty and its relationship with short-term patient function.

PURPOSE: Total hip arthroplasty (THA) is commonly used worldwide in pelvic osteoarthritis treatment. This surgery can change the spinopelvic parameters, which in turn affects the performance of the patients after surgery. However, the relationship between functional disability following THA and spinopelvic alignment is not completely understood. The limited available studies have also been conducted on the population with spinopelvic malalignments. This study aimed to examine the changes in spinopelvic parameters after primary THA in patients with normal preoperative spinopelvic characteristics and the association of these parameters with the performance, gender, and age of the patients after THA. METHODS: Fifty-eight eligible patients with unilateral primary hip osteoarthritis (HOA) scheduled for total hip arthroplasty between February and September 2021 were studied. Spinopelvic parameters including pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) were measured before surgery and three months after surgery, and the relationship between these parameters and patients' performance (Harris hip score) was assessed. Also, the relationship between the age and gender of the patients with these parameters was evaluated. RESULTS: The mean age of study participants was 46.03 ± 14.25. Three months after THA, sacral slope decreased with the mean difference of 4.31 ± 10.26 degrees (p = 0.002) and Harris hip score (HHS) increased by 19.41 ± 26.55 points (p < 0.001). With increasing age in patients, the mean SS and PT decreased. Among the spinopelvic parameters, SS (ß = 0.11) had a greater effect than PT on postoperative HHS changes and among the demographic parameters, age (ß = -0.18) had a greater effect on HHS changes than gender. CONCLUSION: Spinopelvic parameters are associated with age, gender, and patient's function after THA as sacral slope decreased and HHS increased after THA, and aging is accompanied by lowering of PT and SS.

A New Concept of Using Femoral Condyles Surface for Femoral Component Alignment During Total Knee Arthroplasty: A Technical Note.

Background: Orthopedic surgeons favor an intramedullary guiding system on the femoral component during total knee arthroplasty (TKA); nevertheless, improper positioning of the entry point affects the final alignment. We have designed a new femoral cutting system for TKA that uses the distal and posterior femoral condyles as reference points for the setting of the cutting system regardless of the femoral canal. This study aims to evaluate the outcomes of this new guiding system. Methods: We enrolled a series of 75 consecutive knees undergoing TKA. The alpha, gamma, and hip-knee-ankle (HKA) angles were assessed three months postoperatively. Also, surgical time and intraoperative blood loss were recorded for all patients. Results: Fifteen patients underwent TKA using the mechanical alignment (MA) strategy, and 60 underwent kinematically aligned (KA) TKA. Both groups showed normal coronal and sagittal alignment 3 months postoperatively. The mean intraoperative blood loss was 213.11 ± 52.73 ml, which was not different between the two groups (n.s.). The mean surgical time was 43.12 ± 11.62 min, which was significantly shorter in the KA-TKA (41.11 ± 3.77 min) than in the MA-TKA (49.34 ± 4.56 min) (P < 0.001). Conclusion: Using the new guiding system with good femoral alignment, we introduced the easily palpable and available condylar surface as a new landmark for cutting the distal femur in TKA. Level of Evidence: IV.