Reasons for dissatisfaction with total knee arthroplasty (TKA) include unequal flexion or extension gap, soft tissue imbalance, and patella maltracking, which often occur with mismatch between femoral and tibial coronal bony alignment in the knee joint or extremely varus or valgus alignment. However, lower limb coronal alignment classification is based only on hip–knee–ankle angle (HKAA), leading to oversight regarding a mismatch between femoral and tibial coronal alignment. We aimed to classify alignment of the lower limbs according to the mechanical alignment of the femur and tibia in a healthy population. All 214 normal triple films were reviewed retrospectively. HKAA, mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), angle between the femoral anatomical axis and the mechanical axis (AA-MA), and knee alignment angle (KAA) were measured. Subjects were categorized into one of five types based on the mechanical alignment of femur and tibia. Mean HKAA, mLDFA, and mMPTA of all subjects were 1.2°, 87.3°, and 85.8°, respectively. All subjects were classified into one of five types with significant differences (p < 0.001). About 61% of subjects showed neutral alignment, of which nearly 40% were type 2 (valgus of the femur and varus of the tibia with oblique joint line: mLDFA 85.0° ± 1.4°, mMPTA 85.1° ± 1.2°, TJLA 2.7° ± 2.4°) and 60% exhibited neutral alignment with a neutral femur and tibia (type 1). In varus and valgus types, mismatch between the mechanical angle of the femur and tibia was common. Varus alignment, including types 3 (varus of the tibia: mLDFA 88.0° ± 1.4°, mMPTA 83.5° ± 1.6°) and 4 (varus of both the tibia and femur: mLDFA 91.4° ± 1.4°, mMTPA 85.2° ± 2.0°), was found in 30% of subjects. Valgus alignment (type 5 valgus of femur: mLDFA 84.6° ± 1.6°, mMPTA 88.8° ± 2.0°) accounted for 8.9% of all subjects. Mismatch between mechanical alignment of the femur and tibia was common in varus and valgus alignment types. Joint line obliquity was also observed in 40% of the neutral alignment population. This classification provides a quick, simple interpretation of femoral and tibial coronal alignment, and more detailed guidance for preoperative planning for TKA than the traditional varus–neutral–valgus classification.

Robot-assisted pedicle screw placement for spine surgery has become popular in recent years. This study compares clinical, radiographic outcomes and the screw loosening rate between robot-assisted and fluoroscopy-guided pedicle screw placement in patients who underwent transforaminal lumbar interbody fusion (TLIF). We retrospectively examined 108 patients with the degenerative lumbar disease who underwent TLIF. According to whether the robotic system was used, patients were assigned to either the robot-assisted (Ro TLIF, n = 29) or fluoroscopy-guided TLIF (FG TLIF, n = 79) group. Radiographic parameters and patient-reported outcomes, including leg and back pain visual analog scale (VAS) and Oswestry Disability Index (ODI), were assessed. Loosening signs were noted in 48 out of 552 pedicle screws. The screw loosening rate was higher in the FG TLIF (10.2%) than Ro TLIF group (4.3%). A significant correlation was found between screw loosening and age, the number of level(s) fused, and the ratio of the average distance from the pedicle screw to the upper endplate to vertebral body height. VAS-leg, VAS-back, and ODI showed significant improvements in both groups postoperatively (all p < 0.05). These results indicated that robot-assisted pedicle screw placement in TLIF had a lower screw loosening rate and similar patient-reported outcomes compared with the fluoroscopy-guided technique.

The relationship between quantitative anatomic parameters in MRI and patient-reported outcomes (PROs) before and after surgery in degenerative lumbar foraminal stenosis remains unknown. We included 58 patients who underwent transforaminal lumbar interbody fusion (TLIF) for single-level degenerative disc disease with foraminal stenosis between February 2013 and June 2020. PROs were evaluated using the visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and EuroQol-5D (EQ-5D). The foraminal parameters assessed using preoperative MRI included foraminal height, posterior intervertebral disc height, superior and inferior foraminal width, and foraminal area. The correlation between foraminal parameters and PROs before operation, at 1 year follow-up, and change from baseline were assessed. The associations between the aforementioned parameters were examined using linear regression analysis. The analysis revealed that among these parameters, superior foraminal width was found to be significantly correlated with ODI and EQ-5D at the 1 year follow-up and with change in ODI and EQ-5D from baseline. The associations remained significant after adjustment for confounding factors including age, sex, body mass index, and duration of hospital stay. The results indicated that in degenerative lumbar foraminal stenosis, decreased superior foraminal width was associated with better improvement in disability and quality of life after TLIF.

Background/Objectives: Various surgical approaches have been proposed for treating adjacent segment disease (ASD) after lumbar fusion. However, studies using oblique lumbar interbody fusion (OLIF) to treat ASD are lacking. The current study assessed the postoperative outcomes of single-level OLIF for ASD, comparing the results with those for patients undergoing transforaminal lumbar interbody fusion (TLIF). Methods: Patients who underwent single-level OLIF or TLIF for lumbar ASD were retrospectively included. Clinical outcomes, that is, the results of assessments using the Euroqol 5-Dimension quality of life scale (EQ-5D), the Oswestry Disability Index, and the visual analog scale, were evaluated. Radiologic parameters, including disc height (DH), segmental lordosis (SL), segmental coronal angle (SCA), lumbar lordosis, and pelvic incidence–lumbar lordosis mismatch, were also assessed. Results: A total of 65 patients were enrolled: 32 in the OLIF group and 33 in the TLIF group. The median follow-up time was 24.0 months in both groups. The clinical outcomes and radiologic parameters significantly improved in both groups postoperatively. According to intergroup comparisons, the OLIF group had significantly less blood loss and superior improvement in radiologic parameters (DH, SL, and SCA) whereas the TLIF group had significantly shorter operation times. For the OLIF patients who did not undergo posterior decompression, the operation time was similar to that of the TLIF group, but the surgical blood loss and length of hospital stay were significantly reduced compared with the TLIF group. Conclusions: Compared with TLIF, OLIF provides similar clinical outcomes, leads to less surgical blood loss, and has superior radiologic parameters; however, the operation time is significantly longer. OLIF without posterior decompression may be a superior option to TLIF for certain patients.

We aimed to investigate the association between preoperative body mass index (BMI) and postoperative long-term mortality in patients who underwent a vertebroplasty. We retrospectively enrolled patients with a vertebral compression fracture who underwent a vertebroplasty between May 2013 and June 2020 in a medical center in Taiwan. The survival status of the study sample was confirmed by the end of March 2021. Cox-proportional hazard models were conducted to examine the effects of being overweight/obese (≥25 kg/m² vs. <25 kg/m²) and BMI (as a continuous variable) on all-cause mortality after adjusting for age, sex, history of smoking, diabetes, hypertension, chronic kidney disease, and osteoporosis. A total of 164 patients were analyzed (mean age 75.8 ± 9.3 years, male 25.6%, mean BMI 24.0 ± 4.1 kg/m²) after a median follow-up of 785 days. Compared with a BMI < 25 kg/m², a BMI ≥ 25 kg/m² was associated with a significantly lower risk of all-cause mortality (HR 0.297, 95% CI 0.101 to 0.878, p = 0.028). These findings were consistent when BMI was examined as a continuous variable (HR 0.874, 95% CI 0.773 to 0.988, p = 0.031). A low BMI (<22 kg/m²) should be considered as a risk factor for postoperative long-term mortality in this ageing population.

Introduction: Oswestry Disability Index (ODI) and EuroQol-5D (EQ-5D) have been widely used to assess general health quality and function in clinical studies of patients with vertebral fractures. We aimed to investigate the associations of preoperative ODI and EQ-5D with long-term mortality in patients undergoing percutaneous vertebroplasty.Material and methods: We retrospectively identified adult patients who had a single-level vertebral compression fracture and received percutaneous vertebroplasty between 2013 and 2020. Patients with traumatic fractures, burst fractures, and pathologic fractures, as well as those who had missing information on preoperative assessment of ODI and EQ-5D, were excluded. Survival status of the study patients was confirmed at the end of March 2021. The associations of preoperative ODI and EQ-5D with all-cause mortality were examined using Cox-proportional hazard models.Results: A total of 167 patients were analyzed (mean age 75.8 ± 9.3 years, 25.7% male). There were 28 patients who died during a median follow-up duration of 2.1 years (63.6 per 1000 patient-years). Preoperative ODI was significantly associated with all-cause mortality after vertebroplasty (HR 1.049, 95% CI 1.008 to 1.092, p=0.018). In contrast, preoperative EQ-5D was independently associated with a lower risk of all-cause mortality after the surgery (HR 0.202, 95% CI 0.043 to 0.936, p=0.041).Conclusions: Preoperative assessment of ODI (HR 1.049, 95% CI 1.008 to 1.092) and EQ-5D (HR 0.202, 95% CI 0.043 to 0.936) may help determine postoperative long-term mortality risk in this aging surgical population.