The anatomical features of the lateral femoral cutaneous nerve with total hip arthroplasty: a comparative study of direct anterior and anterolateral supine approaches.

BACKGROUND: Lateral femoral cutaneous nerve (LFCN) injury after total hip arthroplasty causes patient dissatisfaction. This cadaveric study aimed to assess the risk for LFCN injury after the direct anterior approach (DAA) and anterolateral supine approach (ALS) with a focus on the anatomical variations of the LFCN. METHODS: Thirty-seven hemipelves from 20 formalin-preserved cadavers (10 males and 10 females) were dissected to identify the LFCN, evaluate variations, and measure the distance from the LFCN to each approach. The LFCN was classified as classical, late, multi trunk, or primary femoral. RESULTS: There were no significant variations in the LFCN between the sexes. The distance from the LFCN to DAA incision (10 [0-17.8] mm) was significantly less than that from the LFCN to ALS incision (27 [0-40] mm); moreover, 64.9% of DAA incisions crossed the LFCN. The classical type LFCN was closest to the DAA incision. The DAA incision most frequently crossed the LFCN at the proximal third, and the frequency of intersection of the LFCN and DAA incisions decreased by 25% by a 10-mm shortening of the DAA proximal incision. In contrast, 27% of ALS incisions crossed the LFCN. Multi trunk type LFCN was closest to the ALS incision. There were no significant differences between each approach and LFCN variations, and the frequency of intersection of the LFCN and ALS incisions decreased by 20% by a 10-mm shortening of the ALS proximal incision. CONCLUSIONS: The intersection rates between the LFCN and the DAA and between the LFCN and the ALS were approximately 65 and 30%, respectively. Approximately 20-25% of these injuries may be avoidable by a 10-mm shortening of the proximal incision.

Comparison of properties determined using electromechanical assessment (Arthro-BST™) with macroscopic and histological properties in symptomatic human articular cartilage of the hip.

BACKGROUND: Cartilage degeneration is assessed using various methods. Although macroscopic evaluation can directly measure cartilage degeneration, it cannot accurately assess cartilage properties. Histological examination is one of the most accurate methods for evaluating cartilage degeneration. However, it is invasive and requires collection of cartilage tissue. In contrast, the Arthro-BST™ probe can assess cartilage properties noninvasively. This study aimed to evaluate the effectiveness of the Arthro-BST in assessing cartilage degeneration by comparing macroscopic (International Cartilage Repair Society [ICRS] classification) and histological evaluations (modified Mankin score and Osteoarthritis Research Society International [OARSI] histological grade). METHODS: Fourteen femoral heads were excised from 13 patients during surgery to treat hip osteoarthritis or femoral fracture. The ICRS score was used for macroscopic evaluation of cartilage degeneration. The Arthro-BST was applied at sites matching the areas of cartilage damage. The sites assessed using the ICRS classification and Arthro-BST were evaluated histologically (modified Mankin score and OARSI histological grade), and these were compared with the Arthro-BST results. RESULTS: The ICRS classification identified significant differences between grades 1 and 3 (p < 0.01), between grades 1 and 4 (p < 0.01), between grades 2 and 3 (p < 0.01), and between grades 2 and 4 (p < 0.01). Significant correlations were observed between the Arthro-BST results and the ICRS score, modified Mankin score (structure, cellularity, matrix staining, total score), and OARSI histological grade. CONCLUSIONS: In the assessment of hip osteoarthritis, the Arthro-BST results correlated with those of macroscopic and histological evaluations. The Arthro-BST is useful for assessing hip osteoarthritis and may be helpful for noninvasive assessment of cartilage degeneration.

Effect of Platelet-Rich Plasma on M1/M2 Macrophage Polarization.

Osteoarthritis of the knee (OAK) is a chronic degenerative disease and progresses with an imbalance of cytokines and macrophages in the joint. Studies regarding the use of platelet-rich plasma (PRP) as a point-of-care treatment for OAK have reported on its effect on tissue repair and suppression of inflammation but few have reported on its effect on macrophages and macrophage polarization. Based on our clinical experience with two types of PRP kits Cellaid Serum Collection Set P type kit (leukocyte-poor-PRP) and an Autologous Protein Solution kit (APS leukocyte-rich-PRP), we investigated the concentrations of humoral factors in PRPs prepared from the two kits and the effect of humoral factors on macrophage phenotypes. We found that the concentrations of cell components and humoral factors differed between PRPs purified using the two kits; APS had a higher concentration of M1 and M2 macrophage related factors. The addition of PRP supernatants to the culture media of monocyte-derived macrophages and M1 polarized macrophages revealed that PRPs suppressed M1 macrophage polarization and promoted M2 macrophage polarization. This research is the first to report the effect of PRPs purified using commercial kits on macrophage polarization.

Evaluation of muscle volume and degeneration after total hip arthroplasty: a comparison of the posterolateral approach and the anterolateral supine approach.

BACKGROUND: Muscle strength around the hip after total hip arthroplasty (THA) is crucial for preventing dislocation and limping. This study aimed to assess and compare muscle volume and degeneration after THA using the posterolateral (PL) and anterolateral (AL) approaches. METHODS: Sixty-four hips in 64 patients who underwent primary THA were retrospectively analyzed. Patients were segregated into the PL group (35 hips) and AL group (29 hips) for evaluating pre- and postoperative muscle volumes and degeneration around the hip. Computed tomography (CT) examinations were performed preoperatively and 6 months post THA. The muscle volume and Hounsfield units (HU) of the gluteus maximus (G-max), gluteus medius (G-med), tensor fasciae latae, internal obturator muscle, and external obturator muscle were measured. RESULTS: In the PL group, the postoperative muscle volume of the G-max significantly increased than the preoperative muscle volume. In contrast, the postoperative muscle volume of the internal obturator muscle was significantly lower than the preoperative muscle volume. The postoperative HU of the internal and external obturator muscles were significantly lower than the preoperative HU. In the AL group, the postoperative muscle volumes of the G-max, G-med, and tensor fasciae latae significantly increased than their preoperative muscle volumes. The postoperative HU of the G-med and tensor fasciae latae were significantly higher than the preoperative HU values. CONCLUSION: The PL approach can lead to degeneration of the internal and external obturator. The AL approach is more beneficial for recovering the G-med, tensor fasciae latae, and internal obturator muscle than the PL approach.