Fracture risk assessment of vascularized medial femoral condylar bone graft: A finite element analysis.

BACKGROUND: Vascularized medial femoral condyle (MFC) bone graft is useful for pseudarthrosis and osteonecrosis, but has the risk of fracture as a complication. This study aimed to create multiple three-dimensional (3D) finite element (FE) femur models to biomechanically evaluate the fracture risk in the donor site of a vascularized MFC bone graft. METHODS: Computer tomography scans of the femurs of nine patients (four males and five females) with no left femur disease were enrolled in the study. A 3D FE model of the left femur was generated based on the CT images taken from the patients. The descending genicular artery (DGA), the main nutrient vessel in vascularized MFC bone grafts, divides into the proximal transversal branch (TB) and the distal longitudinal branch (LB) before entering the periosteum. Thirty-six different bone defect models with different sizes and locations of the harvested bone were created. RESULTS: The highest stress was observed in the proximal medial and metaphyseal portions under axial and external rotation, respectively. In the bone defect model, the stress was most elevated in the extracted region's anterior or posterior superior part. Stress increased depending on proximal location and harvested bone size. CONCLUSION: Increasing the size of the bone graft proximally raises the stress at the site of bone extraction. For bone grafting to non-load-bearing areas, bone grafting distally using LB can reduce fracture risk. If TB necessitates a larger proximal bone extraction, it is advisable to avoid postoperative rotational loads.

Change in hip laxity after anterior capsular suture in total hip arthroplasty using direct anterior approach.

It is clinically unclear whether anterior capsular suture improves hip laxity in total hip arthroplasty using direct anterior approach (DAA-THA). This study aimed to clarify the impact of anterior capsular suture for hip laxity in DAA-THA. In this study, 121 hips of 112 patients who underwent DAA-THA were prospectively enrolled. Mean age was 64.7 ± 10.1 years, and the subjects consisted of 35 hips in 32 men and 86 hips in 80 women. To evaluate hip laxity after implantation, axial head transfer distance (HTD) when the hip was pulled axially at 15 kg was compared before and after anterior capsular suture at the hip intermediate and 10° extension positions. HTD in the intermediate and 10° extension positions averaged 5.9 ± 4.6 mm and 6.3 ± 4.6 mm before the suture, and 2.6 ± 2.7 mm and 2.9 ± 3.1 mm after the suture, respectively. HTD after the suture significantly decreased in both hip positions (p < 0.0001). The amount of change by the suture was greater in cases with greater pre-suturing HTD. In DAA-THA, the anterior capsular suture significantly improved hip laxity against axial traction force, it may contribute to improvement of postoperative hip stability, especially in cases with greater laxity before the suture.

Negative correlation between central sensitization and forgotten joint score-12 after total hip arthroplasty.

BACKGROUND: Central sensitization is a condition in which even mild stimuli cause pain due to increased neuronal reactivity in the dorsal horn of the spinal cord. It is one of factors of chronic pain in patients with osteoarthritis. However, it is unknown whether central sensitization relates to clinical outcomes after total hip arthroplasty (THA). This study aimed to clarify whether preoperative central sensitization relates to the forgotten joint score-12 (FJS) after THA. Moreover, the secondary outcome was to identify which items in the FJS were most related by central sensitization. METHODS: This retrospective analysis included 263 hips (263 patients; 51 males and 212 females) that underwent primary THA in our institute and were available for evaluation one year postoperatively. The average patient age was 64.8 ± 11.9 years. The Central Sensitization Inventory (CSI) part A, which is a patient-reported outcome, was used to measure preoperative central sensitization. The correlation between preoperative CSI and postoperative FJS and the association between postoperative FJS and preoperative CSI severity were determined. Moreover, difference in each FJS item was evaluated by CSI severity. RESULTS: Twenty-six patients (9.9%) had central sensitization preoperatively. Preoperative CSI scores and postoperative FJS were negatively correlated (r = - 0.331, p < 0.0001). The postoperative FJS was significantly lower in patients with moderate or higher preoperative CSI severity than that in patients with subclinical or mild preoperative CSI severity (p < 0.05). FJS items with movement of daily life were significantly worse in the moderate or higher CSI severity compared with subclinical group (p < 0.05 or p < 0.01). CONCLUSION: Central sensitization prior to THA negatively related to postoperative FJS. In particular, the relationship of central sensitization was found to be significant in FJS items with movement, which would lead to lower patient satisfaction after THA. To get better postoperative outcomes in patients with preoperative central sensitization, improving central sensitization would be important.

Comparison of simultaneous versus staged bilateral total hip arthroplasty via the direct anterior approach: A propensity score matched analysis.

PURPOSE: It remains unclear whether simultaneous bilateral total hip arthroplasty (SimBTHA) or staged bilateral total hip arthroplasty (StaBTHA) is clinically superior. No study has compared these two procedures matching surgical approach and patient background. This study aimed to clarify the differences between SimBTHA using direct anterior approach (SimBTHA-DAA) and StaBTHA using the direct anterior approach (StaBTHA-DAA). METHODS: Patients who underwent THA between 2012 and 2020 were enrolled, resulting in a total of 1658 hips of 1388 patients. After propensity score matching for patient background, 204 hips of 102 patients (51 patients in each group) were examined. Clinical and radiographic outcomes, complications, intraoperative blood loss and blood transfusions (BT) were evaluated. In complications, we evaluated periprosthetic fractures, pulmonary embolism, deep venous thrombosis, surgical site infection and dislocation. RESULTS: At the final follow-up, clinical and radiographic outcomes and complications were not significantly different between the groups. Intraoperative blood loss was equivalent for SimBTHA and the sum in the first- and second-stage StaBTHA. The total-BT rate was significantly higher for SimBTHA-DAA than for StaBTHA-DAA (p < .0001). The allogeneic BT rate was significantly higher in SimBTHA-DAA in the supine position (32.3%) than in StaBTHA-DAA (8.3%) (p = .007). However, no patient who received autologous BT required allogeneic BT. CONCLUSIONS: Clinical and radiographic outcomes were equivalent between SimBTHA-DAA and StaBTHA-DAA. The allogeneic BT rate was significantly higher in SimBTHA-DAA than in StaBTHA-DAA. Autologous BT reduced the use of allogeneic BT in SimBTHA-DAA. Auto-BT may be useful for avoiding allo-BT in SimBTHA.

Medial Soft Tissue-Preserving Technique Impact on Sagittal Stability in Bi-cruciate Stabilized Total Knee Arthroplasty.

Background: Sagittal stability in total knee arthroplasty is achieved through complex processes enabled by prosthetic design and intraoperative soft tissue balancing. This study investigated the effects of preserving medial soft tissue on sagittal stability in bicruciate stabilized total knee arthroplasty (BCS TKA). Method: This retrospective study included 110 patients who underwent primary BCS TKA. The patients were divided into two groups: 44 TKAs were performed releasing medial soft tissue (CON group), and 66 TKAs were performed preserving medial soft tissue (MP group). We assessed joint laxity using tensor device and anteroposterior translation immediately after surgery using the arthrometer at 30° knee flexion. Propensity score matching (PSM) was performed according to preoperative demographic and intraoperative medial joint laxity, and further comparisons between the two groups were performed. Result: After PSM analysis, medial joint laxity in the mid-flexion range tended to be smaller in the MP group than in the CONT group, with a significant difference at 60 degrees (CON group: - 0.2 ± 0.9 mm, MP group: 0.8 ± 1.3 mm, P < 0.05). Anteroposterior translation was significantly different between the two cohorts (CON group: 11.6 ± 2.5 mm, MP group: 8.0 ± 3.1 mm, P < 0.001). Conclusion: This study demonstrated the effects of preserving medial soft tissue on postoperative sagittal stability in BCS TKA. We concluded that this surgical procedure enhances postoperative sagittal stability in the mid-flexion range in BCS TKA.

Forgotten joint score is worse when the affected leg perceived longer than shorter after total hip arthroplasty.

BACKGROUND: One of the causes of patient dissatisfaction after total hip arthroplasty (THA) is leg length discrepancy (LLD). Even when radiographic LLD (R-LLD) is within 5 mm, some people perceive the affected side to be longer, while others perceive it is shorter. The purpose of this study was to investigate the relationship between perceived LLD (P-LLD), R-LLD, and Forgotten Joint Score (FJS-12) after THA. METHODS: A retrospective study of 164 patients with unilateral hip disease was conducted. Based on P-LLD after THA, they were classified into three categories: perceived short (PS 21 patients), no LLD (PN 121 patients), and perceived long (PL 22 patients). On the other hand, based on R-LLD after THA, they were divided into < - 5 mm (RS 36 patients), - 5 mm ≤ x < 5 mm (RN 99 patients), and 5 mm ≥ (RL 29 patients), respectively. The proportion of P-LLD in the RN group was also evaluated. In each group, the relationship between P-LLD, R-LLD and FJS-12 was investigated. RESULTS: After THA, the PL group had significantly worse FJS-12 (PS: 68.3 ± 26.2, PN: 75.0 ± 20.9, PL: 47.3 ± 25.2, P < .0001). In the R-LLD evaluation, there was no difference in FJS-12 among the three groups (RS: 73.7 ± 21.1, RN: 70.0 ± 24.5, RL: 67.7 ± 25.4, P < .53). The RN group perceived leg length to be longer (RN-PL) in 12.1% of cases, and the RN-PL groups had significantly worse FJS-12 (RN-PS: 65.4 ± 24.8, RN-PN: 73.8 ± 23.1, RN-PL: 41.8 ± 27.6, P < .0001). CONCLUSION: One year after THA, patients with longer P-LLD had worse FJS-12, even if the R-LLD was less than 5 mm.

Evaluation of the reproducibility of preoperative three-dimensional computed tomography planning for posterolateral approach total hip arthroplasty.

The anteversion of the stem is occasionally intentionally changed by the surgeon for patients with smaller femoral neck anteversion during total hip arthroplasty (THA). However, the reproducibility of preoperative planning with increasing anteversion has been rarely assessed. The present study investigated it using two types of stems. This retrospective study included patients who underwent primary posterolateral THA using taper-wedge (TS group; 73 hips) and anatomical (AS group; 70 hips) stems. Characteristics of sex and age were matched in the two groups by propensity score matching. In both groups, the relationship between the preoperative three-dimensional planning and postoperative stem position, and the relationship between postoperative stem position and femoral neck anteversion (FNA) were evaluated. In the TS group, there were no significant differences in average stem anteversion (SA) between preoperative planning and postoperative placement (36.1° ± 7.0° and 36.6° ± 11.1°, respectively: p = 0.651). The absolute error of SA was 8.1° ± 6.4°. In the AS group, the postoperative SA was significantly smaller than the preoperative planning SA (22.7° ± 11.6° and 30.0° ± 9.3°, respectively: p < 0.001). The absolute error of SA was 9.0° ± 5.8°. The postoperative SA was significantly larger than the FNA in the TS group (36.6° ± 11.1° and 26.3° ± 10.9°, respectively: p < 0.001). However, no significant differences between the two were observed in the AS group (23.7° ± 10.1° and 22.7° ± 11.6°, respectively: p = 0.253). The preoperative planning of intentional increasing anteversion did not show high reproducibility with taper-wedge and anatomical stems. The anatomical stem was placed according to the femoral medullary canal regardless of preoperative planning with increased SA.

Comparing postoperative outcomes of two fully hydroxyapatite-coated collarless stems in total hip arthroplasty through propensity score matching analysis with 2 years follow-up.

A fully hydroxyapatite (HA)-coated stem such as Corail stem, that compacts the cancellous bone around the stem in total hip arthroplasty (THA), is reported to have good long-term results for more than 20 years. Although various fully HA-coated stems have being used recently, it is unclear whether there are differences in the postoperative outcomes. In this study, 224 patients (234 hips) with THA using either the Corail collarless stem or the Hydra stem were enrolled. And then we performed a retrospective comparison of the data at 2 years postoperatively using propensity score matching analysis. The postoperative modified Harris hip scores in 84 hips each group were 93.6 ± 8.2 points in the Corail group and 92.8 ± 10.1 points in the Hydra group, and there was no significant difference between the two groups. However, there was significantly less stem subsidence and rate of 3rd degree or greater stress shielding in the Corail group. Although these two stems were similar collarless fully HA-coated stems and clinical outcomes were favorable results in both groups at 2 years postoperatively, radiographic evaluations showed statistically significant differences between the two groups.

Intraoperative determination of the risky angles and safe distances for preventing deep femoral artery injury during proximal femoral nailing for hip fractures in Asian people.

OBJECTIVE: During proximal femoral nailing, deep femoral artery injury, a rare condition, is often missed and found late, leading to intractable complications such as false aneurysm, hematoma, and anemia. We aimed to determine the novel indicators of the high-risk vertical range and axial angle for deep femoral artery injury that can be easily confirmed intraoperatively using fluoroscopy for hip fracture. METHODS: In a single hospital, the lower extremity computed tomography angiographies of 88 patients (50 men and 38 women) were analyzed. A reference plane was defined as the femoral neck and shaft on the same straight line in the lateral view. Reference points were the lower end of the lesser trochanter and distal femur at 140 mm from the tip of the greater trochanter. To determine the high-risk angle for deep femoral artery injury based on the reference plane, the angle from the reference plane to the deep femoral artery (bone-arterial angle) and the shortest distance between the surfaces of the femur and the deep femoral artery (bone-artery distance) were measured at the lesser trochanter and the greater trochanter. We analyzed the bone-arterial angle and bone-artery distance values, their differences among the sexes, and their correlation with body height and body weight. RESULTS: Overall, in the lesser trochanter, the mean bone-arterial angle and bone-artery distance were 19.2° ± 8.0° and 22.9 ± 4.7 mm, respectively. In the greater trochanter, the mean bone-arterial angle and bone-artery distance were -33.9° ± 17.0° and 11.3 ± 4.1 mm, respectively. The mean bone-artery distance of the lesser trochanter was significantly longer in men than in women (24.1 ± 4.5 mm and 21.4 ± 4.5 mm, respectively, P < 0.01), and for the lesser trochanter, positive correlations were found between body height and both bone- arterial angle and bone-artery distance (r=0.373, P < 0.001; and r=0.456, P < 0.0001, respectively), with body weight and bone-artery distance positively correlated (r=0.367, P < 0.001). At the greater trochanter, there were negative correlations between body height and bone-arterial angle (r=-0.5671, P < 0.0001), body weight, and bone-arterial angle (r=-0.338, P < 0.01). CONCLUSION: The knowledge of our reference plane and high-risk angles and distances allows surgeons to minimize the risk of deep femoral artery injury. These are easily confirmed intraoperatively using fluoroscopy, allowing surgeons to avoid maneuvering in the deep femoral artery range. LEVEL OF EVIDENCE: Level IV, Diagnostic Study.

Low psoas major muscle area as a risk factor for contralateral hip fracture following intertrochanteric fracture.

OBJECTIVE: This study aimed to investigate the relationship between the psoas major muscle area as a risk factor and subsequent contralateral hip fractures in patients with initial intertrochanteric fractures. METHODS: Of 136 treated for intertrochanteric fractures, 104 female patients had computed tomography done to assess their fractures at initial stage and had been followed up for more than 2 years. These patients were then divided into 2 groups: i.e. those who had a contralateral hip fracture (CF) (n=16) and those who did not (NF) (n=88) groups. We mainly assessed the relationship between the corrected psoas major muscle area (CPMA) at initial fracture and the occurrence of contralateral hip fracture. RESULTS: The CF group had significantly lower CPMA than the NF group (p=0.001). There was positive correlation between the CPMA and the period from the initial to the contralateral hip fracture in the CF group. The CPMA cutoff value of 480.98 mm2/m2, was showed sensitivity of 63.6% and specificity of 87.5% in receiver operating characteristic curve analysis for all patients. CONCLUSIONS: The lower CPMA was associated with the contralateral hip fracture within 2 years from initial intertrochanteric fracture. The low CPMA would be a risk factor for contralateral hip fracture.

Compensation of pulmonary function after upper lobectomy versus lower lobectomy.

OBJECTIVE: Major lung resection may induce expansion of the remaining lung, accompanied by some gain in the function of this lung; however, the impact of the site of resection on this compensatory response remains unclear. METHODS: We measured computed tomography-based functional lung volume, representing normal lung attenuation (-600 to -910 Hounsfield units), and spirometry-based lung function (forced expiratory volume in 1 second) preoperatively and 6 months postoperatively in patients with lung cancer and compared them between patients undergoing upper lobectomy (n = 34) and patients undergoing lower lobectomy (n = 26). RESULTS: We removed 17% ± 4% of the functional lung volume by upper lobectomy and 27% ± 5% by lower lobectomy (P < .001). Postoperatively, the residual lung expanded by various degrees, accompanied by a proportionate gain in the residual lung function (R = 0.6, P < .001). This anatomic and functional compensation of the residual lung was more remarkable after lower lobectomy than after upper lobectomy (P <.05). Consequently, the percentage loss of the functional lung volume after upper lobectomy (10% ± 10%) did not differ significantly from that after lower lobectomy (9% ± 12%, P = .6). Likewise, the percentage loss of lung function after upper lobectomy (12% ± 16%) did not differ significantly from that after lower lobectomy (14% ± 17%, P = .6). CONCLUSIONS: Although the lower lobectomy implies greater resection than the upper lobectomy, lung function after lower lobectomy was not inferior to that after upper lobectomy because the compensatory response appeared more robust after lower lobectomy.