Given the close functional connection between the hip and the spine, their simultaneous degenerative pathology is a common problem seen in orthopedic patients and has been termed the “hip spine syndrome”. Demographic change and an increasing number of operations have led to more patients who have undergone both total hip arthroplasty and spondylodesis especially of the lumbar spine. Studies have shown significant dislocation rates in this cohort of as high as almost 30%. Biomechanical studies and considerations show that spinal surgery directly influences the functional acetabular position and, consequently, the position of the acetabular cup, making the correct implantation challenging for the hip surgeon. Spinal fusion affects not only the biomechanics of the spine but also of the hip joint and, for that reason, must accordingly be taken into account when planning total hip arthroplasty.

In total knee arthroplasty (TKA), functional knee phenotypes are of interest regarding surgical alignment strategies. Functional knee phenotypes were introduced in 2019 and consist of limb, femoral, and tibial phenotypes. The hypothesis of this study was that mechanically aligned (MA) TKA changes preoperative functional phenotypes, which decreases the 1-year Forgotten Joint (FJS) and Oxford Knee Score (OKS) and increases the 1-year WOMAC. All patients included in this study had end-stage osteoarthritis and were treated with a primary MA TKA, which was supervised by four academic knee arthroplasty specialists. To determine the limb, femoral, and tibial phenotype, a long-leg radiograph (LLR) was imaged preoperatively and two to three days after TKA. FJS, OKS, and WOMAC were obtained 1 year after TKA. Patients were categorized using the change in functional limb, femoral, and tibial phenotype measured on LLR, and the scores were compared between the different categories. A complete dataset of preoperative and postoperative scores and radiographic images could be obtained for 59 patients. 42% of these patients had a change of limb phenotype, 41% a change of femoral phenotype, and 24% a change of tibial phenotype of more than ±1 relative to the preoperative phenotype. Patients with more than ±1 change of limb phenotype had significantly lower median FJS (27 points) and OKS (31 points) and higher WOMAC scores (30 points) relative to the 59-, 41-, and 4-point scores of those with a 0 ± 1 change (p < 0.0001 to 0.0048). Patients with a more than ±1 change of femoral phenotype had significantly lower median FJS (28 points) and OKS (32 points) and higher WOMAC scores (24 points) relative to the 69-, 40-, and 8-point scores of those with a 0 ± 1 change (p < 0.0001). A change in tibial phenotype had no effect on the FJS, OKS, and WOMAC scores. Surgeons performing MA TKA could consider limiting coronal alignment corrections of the limb and femoral joint line to within one phenotype to reduce the risk of low patient-reported satisfaction and function at 1-year.

Background: As advanced age often leads to accumulating comorbidities, geriatric patients are endangered by serious events during total hip arthroplasty. This study was conducted to explore whether or not the benefit in terms of health-related quality of life (HRQoL) was comparable to younger patients. Methods: At a single academic center, 100 patients meeting the following inclusion criteria were retrospectively recruited: (1) primary arthritis of the hip leading to THA; (2) age 80 years or older at the time of surgery; (3) follow up of at least 12 months. For comparison, two further groups were recruited in the same manner, differing only in the age criterion: 100 patients aged 60–69 and 100 patients aged 70–79 at the time of hip replacement. The primary outcome was compared using the WOMAC and the EQ-5D score. The secondary outcome was determined by rates of orthopedic and non-orthopedic complications. Intragroup comparisons of the PROMS were performed by the non-parametric Wilcoxon test for paired samples. For intergroup comparisons of the PROMS, the Kruskal–Wallis-test was performed. Concerning categorial data, intergroup comparisons were performed by the Chi-Square test. The level of significance was set at 0.05. Results: Concerning the WOMAC score, neither the absolute values at 12 months after THA (p = 0.176) nor the amount of change relative to the values before surgery (p = 0.308) differed significantly between the 3 groups. Concerning the EQ-5D index the absolute values at 12 months after THA differed significantly (p = 0.008). Rates of orthopedic complications did not differ significantly (p = 0.631). Rates of non-orthopedic complications increased significantly with rising age (p = 0.033). Conclusions: Compared to younger patients, geriatric patients after THA have an equal improvement in hip-specific and general HRQoL. While rates of orthopedic complications are comparable too, non-orthopedic complications occur more frequently.