Hakan Batuhan Kaya

Background and Objectives: Nonunion remains an important clinical concern after nonoperative treatment of humeral shaft fractures. Although several patient- and fracture-related variables have been proposed as determinants of healing, their independent contributions remain uncertain. This study aimed to identify patient- and fracture-related factors independently associated with nonunion after nonoperative treatment of humeral shaft fractures. Materials and Methods: This single-center retrospective cohort study included adults with humeral shaft fractures treated nonoperatively between January 2015 and January 2025. Fractures were classified using the AO/OTA system. Patients with periprosthetic, pathological, pediatric, intra-articular fractures, previous nonunion, or insufficient follow-up were excluded. Treatment consisted of functional bracing after initial immobilization. Nonunion was defined as absence of clinical and radiographic union at or beyond 9 months after injury, with no radiographic progression over at least 3 months, persistent fracture-site pain, and absent bridging callus. Demographic characteristics, comorbidities, fracture-related variables, and radiographic parameters were recorded. Multivariable logistic regression was used to evaluate adjusted associations with nonunion, with Firth’s penalized regression performed as a sensitivity analysis. Results: Among 242 patients, union occurred in 207 (85.5%), while 35 (14.5%) developed nonunion. In the adjusted model, older age (OR = 1.76 per 10-year increase; 95% CI: 1.28–2.40), smoking (OR = 14.33; 95% CI: 4.16–49.32), and proximal-third fracture location (OR = 3.77; 95% CI: 1.38–10.31) were associated with nonunion. Firth’s penalized regression yielded similar findings. The association with diabetes mellitus was uncertain (OR = 2.63; 95% CI: 0.94–7.30). Conclusions: Older age, smoking, and proximal-third fracture location were associated with nonunion after nonoperative treatment of humeral shaft fractures. These exploratory associations may inform patient counseling and follow-up, but the limited number of events and wide confidence intervals warrant cautious interpretation.

Background: The Rockwood classification is the most widely used radiographic framework for grading acromioclavicular (AC) joint dislocations. However, native anatomical variation may be associated with differences in the radiographic appearance of AC joint dislocations. Purpose: To evaluate the association between the acromioclavicular joint coronal orientation angle (AJCO) and Rockwood grade and to characterize the relationship between native coronal orientation and radiographic grade. Methods: This retrospective observational radiographic study included 198 adults with acute AC joint dislocations classified as Rockwood II, III, or V on standardized bilateral Zanca radiographs. AJCO was measured on the contralateral, uninjured side as the angle between the AC joint orientation line and a vertical reference. Two blinded orthopedic surgeons performed measurements independently, with reliability assessed using intraclass correlation coefficients. AJCO was compared across Rockwood groups, its monotonic association with grade was evaluated using Spearman correlation, and exploratory receiver operating characteristic analysis was performed for the tested binary contrast. Results: AJCO differed significantly across Rockwood injury grades, decreasing progressively from type II to type V injuries (median [IQR]: type II, 18.3° [14.6–26.0°]; type III, 15.3° [12.0–21.3°]; type V, 14.0° [8.6–18.0°]; p < 0.001). Consistent with this finding, AJCO demonstrated an inverse weak-to-moderate association with Rockwood grade (Spearman ρ = −0.338, 95% CI −0.453 to −0.214; p < 0.001). AJCO showed limited ability to discriminate higher-grade injuries (Rockwood ≥ III), with an AUC of 0.694 (95% CI, 0.612–0.777; p < 0.001), characterized by high specificity but low sensitivity at the optimal threshold. Furthermore, lower AJCO values remained significantly associated with higher Rockwood grades after adjustment for age and sex (OR = 0.899 per degree increase, 95% CI, 0.864–0.935; p < 0.001). Conclusions: Lower AJCO values were associated with higher Rockwood grades in this cohort, but the magnitude of association and discriminatory performance were limited. These findings support AJCO as a morphology-related contextual variable associated with Rockwood grade rather than as a stand-alone diagnostic or treatment-guiding measure.

Objective: This study aimed to evaluate the short-term clinical and radiological outcomes of lower extremity and spinal changes following total hip arthroplasty (THA) in patients with unilateral Crowe type III and IV hip dysplasia. Methods: This prospective study included patients who have Crowe type III and IV hip dysplasia evaluated at a high-volume arthroplasty center. Demographic and surgical characteristics were documented. Clinical assessments included the Harris Hip Score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form-12 (SF-12), Kujala Score, Oxford Knee Score, Oswestry Disability Index (ODI), Roland-Morris Questionnaire, American Orthopedic Foot and Ankle Society (AOFAS) Score, and Foot and Ankle Disability Index (FADI). Radiological assessments included standing anteroposterior (AP) pelvis, AP leg length, and standing/seated lumbosacral AP and lateral radiographs preoperatively and at 1-year postoperatively. Results: Thirty-three patients (mean age 52.7 Å} 11.8 years) were followed for an average of 18.3 Å} 7.0 months. Significant improvements were observed postoperatively in HHS and WOMAC scores for both ipsilateral and contralateral hips, SF-12, ODI, Roland-Morris, and ipsilateral knee WOMAC scores (all P<0.05). Radiologically, postoperative improvements included a significant reduction in leg length discrepancy (P<0.001), medial mechanical axis deviation on the ipsilateral side (P<0.001), increased joint line convergence angle and ankle joint line orientation, and spinopelvic alingment with increased sacral slope (P=0.027) and decreased lumbar lordotic angle (P<0.001). Conclusion: Unilateral high-grade hip dysplasia, when treated with total hip arthroplasty (THA), results in significant short-term improvements in clinical outcomes and lower extremity alignment. In patients with an average follow-up duration of 18.3 Å} 7.0 months, although the valgus deformity on the operated side improved, neutral alignment was not achieved. The contralateral limb remained in varus alignment. While spinopelvic parameters remained within normal limits, significant changes were observed in sacral slope and lumbar lordosis. Cite this article as: Kaya HB, Çiçek EB, Yıldız F, et al. Lower extremity and spinopelvic alignment changes after total hip arthroplasty in unilateral Crowe III-IV dysplasia: clinical and radiological outcomes. Acta Orthop Traumatol Turc., 2026; 60(4), 0689, doi: 10.5152/j.aott.2026.25689.

SUMMARY OBJECTIVE: Accurate identification of the anatomical femoral head center is critical in total hip arthroplasty for optimal implant positioning and long-term survival. The Ranawat triangle method is widely used for this purpose, but its applicability may vary across populations. The aim of this study was to evaluate the accuracy and suitability of the Ranawat triangle method in estimating the anatomical femoral head center in a Turkish population. METHODS: Standardized anteroposterior pelvic radiographs of 260 non-fractured hips from 312 patients aged 60–90 were retrospectively analyzed. Pelvic height, pelvic width, and femoral head diameter were measured. The coordinates of the anatomical femoral head center were calculated anatomically and using the Ranawat triangle method. Deviations between the two were assessed in both axes, with <5 mm considered acceptable error. RESULTS: Anatomical femoral head center estimated by the Ranawat triangle method was positioned an average of 4.7±1.5 mm medially and 1.0±0.8 mm cranially in men, and 4.8±1.1 mm medially and 1.1±0.7 mm cranially in women, relative to the anatomical center. While 100% of Y-axis errors and 58.1% of X-axis errors were within 5 mm. Strong positive correlations were found between pelvic height and Cy (r=0.59), and pelvic width and Cx (r=0.82). CONCLUSION: The Ranawat triangle method method demonstrated excellent accuracy in predicting the vertical (Y-axis) position of the anatomical femoral head center but showed moderate lateral (X-axis) deviations in over 40% of cases. Despite its limitations in lateral offset prediction, it may serve as a practical reference method for preoperative planning, particularly for estimating the vertical position of the hip rotation center in Turkish total hip arthroplasty patients.

Background/Objectives: Reverse shoulder arthroplasty (RSA) has been widely used for the treatment of shoulder pathologies, particularly rotator cuff tear arthropathy. Currently, it is also increasingly performed for different indications. Like in any arthroplasty procedure, periprosthetic joint infection (PJI) is one of the most concerning complications and may have devastating outcomes. This study aimed to identify risk factors for PJI following RSA. Methods: This retrospective case-control study was conducted with patients who underwent RSA during the study period. Based on PJI occurrence during the follow-up period, patients were divided into two groups: Group I (no infection) and Group II (infection). The relationship between numerous clinical variables and PJI was tested. All variables were initially evaluated through univariate analysis between the two groups, and variables showing significant differences between the two study groups were subjected to multivariate logistic regression analysis to determine independent risk factors. Results: The study included 302 patients, with a mean age of 69.6 ± 10.1 years and a mean follow-up duration of 59.8 ± 24.7 months. During the follow-up period, PJI was not detected in 289 patients (95.7%) (Group I), while 13 patients (4.3%) developed PJI (Group II). Univariate analysis revealed a significant association between preoperative C-reactive protein (CRP) value (p = 0.001) and preoperative diabetes history (p = 0.007) with PJI. Multivariate logistic regression analysis, including these two variables, showed that diabetes was an independent risk factor for PJI development (p = 0.01, odds ratio = 4.85). Preoperative CRP elevation was not observed as an independent risk factor. Conclusions: This study demonstrated a significant association between high preoperative CRP levels and diabetes with PJI. Additionally, the presence of diabetes was identified as an independent risk factor for infection, with a 4.85-fold higher risk of PJI development in patients with a history of diabetes.

Background: Recently, the lateralization shoulder angle (LSA) and distalization shoulder angle (DSA) have been proposed to assess lateralization and distalization in reverse shoulder arthroplasty (RSA). However, there is insufficient evidence about the influence of patient anatomy and prosthesis design on these measurements. This study aims to investigate the impact of patient anatomy and implant design on LSA and DSA measurements and to assess the validity of the previously reported “optimal” ranges for these parameters. Methods: Patients who underwent the RSA procedure using four different prosthetic designs between April 2014 and June 2023 were retrospectively evaluated. Postoperative LSA and DSA measurements were compared according to implant design, preoperative glenoid morphology (Favard classification), and the Hamada grade. The correlation of LSA and DSA with preoperative shoulder anatomy (critical shoulder angle, CSA, and acromial index, AI) was also assessed. Results: In total, 135 shoulders were included in the study, with a mean age of 71.7 ± 7.9 years. The mean LSA was 88.4 ± 11.8° and mean DSA was 40.6 ± 12.5°. According to prosthetic design, both mean LSA and DSA values differed significantly (p < 0.05). Lateralized designs (Groups I and IV) had significantly higher mean LSA values. The Favard classification and Hamada grade of shoulders did not show a significant influence on LSA and DSA measurements (p > 0.05). DSA was observed to be significantly correlated with CSA and AI (p < 0.05; r = −0.27 and −0.189, respectively). Conclusions: Prosthetic design and preoperative shoulder anatomy had a significant influence on LSA and DSA measurements in RSA. Optimal LSA and DSA values may lack validity and reliability and should not be applied to all patients.