Background and Objectives: Hip arthroplasty is commonly performed to enhance mobility and quality of life in patients with severe joint degeneration. However, post-surgery complications such as infections, dislocations, and mechanical failures remain prevalent and vary over time. This study examines the relationship between time intervals post-surgery and the occurrence of complications and explores the associations between specific treatment modalities and complications. It also investigates temporal patterns of infectious and mechanical complications to inform more effective post-surgery care. Materials and Methods: A retrospective cohort study was conducted on hip arthroplasty patients to analyze the occurrence and distribution of complications across medium-term (1–5 years) and long-term (≥6 years) intervals. Treatment modalities, including joint debridement, lavage, antibiotics, and mechanical interventions, were analyzed for their association with complications. Chi-Square tests were used, with significance set at p < 0.05. Results: A significant association was found between time intervals and complications (χ² = 58.149, df = 19, p < 0.001). Infections were more prevalent in the medium-term, while mechanical complications such as dislocation, implant loosening, and periprosthetic fractures were more common in the long-term. Antibiotics were strongly linked to infectious complications (χ² = 279.000, p < 0.001), and mechanical treatments were associated with fractures and dislocations. Conclusions: The study confirms that the timing of complications post-surgery plays a critical role in their occurrence. Specific complications become more prevalent at different intervals, emphasizing the need for tailored treatment strategies. Antibiotics for infections and mechanical interventions for fractures and dislocations should be adjusted based on timing. These findings highlight the importance of time-specific post-surgery care and suggest areas for further research on long-term strategies and risk factors.

Background/Objectives: Total hip arthroplasty (THA) remains a widely utilized and effective intervention for patients with end-stage hip osteoarthritis. Although multiple surgical approaches and fixation techniques are available, their application in non-tertiary clinical settings is less frequently documented. This study primarily aims to provide an educational overview of stepwise THA procedures using intraoperative visual documentation, with a secondary, exploratory assessment of postoperative outcomes related to surgical approach and fixation strategy. Methods: A prospective observational study was conducted at Arad Clinical Emergency County Hospital between March 2023 and March 2024, involving 23 patients undergoing primary THA. Patients received either cemented or uncemented femoral components based on intraoperative bone quality. Procedures were documented using stepwise intraoperative photographs and postoperative radiographs. Recovery was assessed using the Harris Hip Score (HHS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at both six weeks and six months postoperatively. Results: Both lateral (Hardinge) and posterolateral approaches provided adequate exposure with reproducible results. Cemented implants allowed for immediate full weight-bearing and were preferred in elderly patients with poor bone quality, while uncemented components were used in younger patients with good bone density, requiring a delayed weight-bearing protocol. Functional scores improved in both groups between six weeks and six months. At six weeks, the mean HHS was 87.6 ± 6.2 and WOMAC 18.3 ± 4.8; by six months, these improved to 91.8 ± 5.1 and 12.7 ± 3.9, respectively. Cemented fixation demonstrated slightly better outcomes at both time points; however, intergroup differences remained below the Minimal Clinically Important Difference (MCID) thresholds. Conclusions: Tailored surgical approaches and fixation strategies, guided by intraoperative assessment, result in favorable short- and mid-term recovery profiles in THA. The integration of intraoperative visual documentation and patient-reported outcome measures (PROMs) enhances procedural transparency while supporting evidence-based decision-making and surgical training.

Background/Objectives: Mechanical alignment (MA) has traditionally been the reference alignment strategy in total knee arthroplasty (TKA), whereas kinematic alignment (KA) has emerged as an individualized alternative intended to approximate patient-specific knee anatomy. However, the relationship between postoperative mechanical-axis alignment and functional recovery remains incompletely understood. This study aimed to compare short-term functional outcomes and postoperative mechanical-axis alignment between MA and KA following primary TKA and to investigate the relationship between measured postoperative alignment parameters and functional outcomes. Methods: This single-center retrospective comparative cohort study included 120 patients who underwent primary unilateral TKA for end-stage knee osteoarthritis (KOA) between January 2022 and December 2024; 51 underwent MA and 69 underwent KA. Radiographic assessment included the hip–knee–ankle (HKA) angle, mechanical-axis deviation (MAD), residual varus deformity, and radiographic knee extension deficit. Functional outcomes were assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Knee Society Score (KSS). Preoperative, postoperative, and change-from-baseline (Δ) functional scores were evaluated. Analysis of covariance (ANCOVA) was used to assess associations between alignment strategy and postoperative functional outcomes after adjustment for baseline functional scores and relevant covariates. Associations between postoperative radiographic parameters and functional outcomes were additionally assessed. Results: Both alignment groups demonstrated substantial preoperative-to-postoperative functional improvement. MA achieved postoperative HKA alignment closer to the neutral mechanical axis than KA (179.63 ± 1.23° vs. 178.24 ± 2.32°; p < 0.001; FDR-adjusted p < 0.001). Absolute HKA deviation from neutral was lower with MA (0.97 ± 0.83° vs. 2.42 ± 1.62°; FDR-adjusted p < 0.001), as was postoperative absolute MAD (5.19 ± 4.53 mm vs. 7.86 ± 6.76 mm; p = 0.011; FDR-adjusted p = 0.018). KA was associated with a higher unadjusted postoperative KOOS score than MA (84.04 ± 12.33 vs. 77.12 ± 15.65; p = 0.010), whereas postoperative WOMAC (p = 0.206) and KSS (p = 0.843) did not differ significantly between groups. Between-group differences in change from baseline were not statistically significant for KOOS (p = 0.227), WOMAC (p = 0.130), or KSS (p = 0.427). After multivariable adjustment, no statistically significant between-group associations were observed for postoperative KOOS (adjusted β = 2.42; 95% CI, −0.93 to 5.77; p = 0.155), WOMAC (adjusted β = −2.80; 95% CI, −6.73 to 1.14; p = 0.162), or KSS (adjusted β = 1.09; 95% CI, −2.05 to 4.24; p = 0.492). Associations between the postoperative radiographic parameters and functional outcomes were negligible to weak, with none remaining statistically significant after FDR correction. Conclusions: Both MA and KA were associated with substantial short-term functional improvement, with no significant between-group differences in the magnitude of improvement from baseline. MA achieved postoperative alignment closer to the neutral mechanical axis, while the higher unadjusted postoperative KOOS score observed with KA was not statistically significant after adjustment for baseline characteristics and potential confounders. No significant postoperative differences in WOMAC or KSS were observed. The generally weak associations between measured postoperative mechanical-axis parameters and functional outcomes suggest that mechanical-axis alignment alone may not adequately explain short-term functional recovery. Because patient-specific coronal alignment parameters and achievement of the individualized KA target were not quantitatively assessed, the present findings cannot determine whether restoration of patient-specific anatomy was associated with functional outcomes.

Background/Objectives: Total knee arthroplasty (TKA) is the standard surgical treatment for end-stage knee osteoarthritis (KOA); however, restoration of normal gait biomechanics remains an important challenge. Objective assessment of gait recovery may provide valuable information beyond conventional clinical outcome measures. This study aimed to evaluate changes in spatiotemporal gait parameters, symmetry restoration, and functional recovery during the first year following primary TKA, and to identify predictors of postoperative gait performance. Methods: A prospective longitudinal cohort study was conducted in 150 patients undergoing primary unilateral TKA for end-stage KOA. Spatiotemporal gait parameters, symmetry-related variables, and functional outcomes were assessed preoperatively and at 3, 6, and 12 months postoperatively. Gait analysis included walking speed, step length, cadence, stance phase symmetry, symmetry index (SI), loading asymmetry, and single-limb support time. Functional evaluation included the Timed Up and Go (TUG) test, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Knee Society Score (KSS). Repeated-measures analysis of variance (ANOVA), Pearson correlation analysis, and multivariate linear regression were performed. Results: Significant improvements were observed in all gait and functional parameters throughout follow-up (all p < 0.001). Walking speed increased from 0.84 ± 0.16 m/s preoperatively to 1.21 ± 0.18 m/s at 12 months, while step length increased from 49.8 ± 7.4 cm to 64.0 ± 6.4 cm and cadence from 91 ± 10 to 108 ± 8 steps/min. SI improved from 73 ± 11% to 93 ± 6%, whereas loading asymmetry decreased from 18.2 ± 6.1% to 4.8 ± 2.3%. Walking speed demonstrated strong correlations with WOMAC score (r = −0.74, p < 0.001) and TUG performance (r = −0.79, p < 0.001). Multivariate regression analysis identified preoperative walking speed (β = 0.47, p < 0.001) as the strongest predictor of postoperative gait recovery, while age and body mass index (BMI) were significant negative predictors. Conclusions: Patients undergoing primary TKA demonstrated substantial improvements in gait biomechanics, symmetry restoration, and functional performance during the first postoperative year. Objective gait assessment was strongly associated with clinical outcomes and may facilitate identification of patients at risk of delayed recovery. Incorporating quantitative gait analysis into postoperative evaluation may support individualized rehabilitation strategies aimed at optimizing functional outcomes following TKA.

Background/Objectives: Achieving optimal primary stability in cemented total hip arthroplasty remains a critical factor influencing long-term implant success. Variability in cementation techniques can significantly affect biomechanical performance, yet consensus on best practices is lacking. This study investigates the influence of cementation parameters on femoral stem fixation. Methods: This in vitro comparative study evaluated four cementation techniques—Classic (line-to-line), Press-Fit (undersized reaming), Overreaming (oversized reaming), and Valgus Malpositioning (15° deviation). An experimental model using standardized Polyurethane (PU) bone surrogates was developed. Mechanical testing assessed axial deformation and ultimate load capacity to failure. Results: The Press-Fit technique demonstrated significantly greater deformation (17.10 ± 0.89 mm) but a reduced load capacity (6317.47 ± 518.34 N) compared to the Classic approach. Overreaming and Valgus techniques both showed reduced mechanical performance, with Overreaming yielding the lowest structural integrity. Conclusions: Cement mantle thickness emerged as the primary determinant of biomechanical stability, surpassing the impact of implant positioning. While increased mantle thickness improves energy absorption, it may compromise ultimate strength. These findings underscore the importance of optimizing the cementation technique to balance flexibility and mechanical resistance, guiding surgical protocols toward improved implant longevity. This study introduces a novel integrative approach combining fluoroscopic assessment of cement mantle morphology with mechanical testing in a standardized model, providing new evidence on the relative influence of mantle thickness and implant malposition on femoral stem stability.