Safe Ultrasonography-Assisted Knee Posterior Transseptal Portal Creation Technique.

Knee arthroscopy is a minimally invasive surgical technique that allows surgeons to diagnose and treat various knee conditions using much smaller incisions than open surgery. However, it is difficult to fully visualize the posterior compartment of the knee joint using the usual anterior portal approach because of blind spots. The transseptal portal technique enables surgeons to visualize the surgical field and access instruments in the posterior compartment of the knee during arthroscopic surgery. However, creation of the posterior transseptal portal increases the risk of neurovascular injury. Particular attention should be paid to avoid damaging the saphenous nerve, common peroneal nerve, popliteal artery, and tibial nerve. Here, we describe an ultrasonography-guided surgical method for creating the posterior transseptal portal by confirming the surrounding anatomy.

Application of Intraoperative CT-Ultrasound Fusion Imaging in Hip Endoscopy for Treatment of Iatrogenic Impingement Due to PLLA Screw: A Novel Surgical Technique.

Ultrasound-assisted surgery is becoming an established tool in the medical field. The addition of imagery to ultrasound-assisted surgery may enable one to perform a procedure in a safer and more accurate manner. This can be achieved through fusion imaging (fusion), a technology that synchronizes MRI or CT images with ultrasound images. We describe intraoperative CT-ultrasound fusion-guided (or -assisted) hip endoscopy for the removal of an impinging poly L-lactic acid screw, which was difficult to identify on fluoroscopy during surgery. The fusion technology enables merging two advantages of ultrasound: the real-time guidance capabilities and CT or MRI and the bird's eye view that makes minimally invasive arthroscopic and endoscopic surgery less invasive, precise, and safe.

Targeting of Periprosthetic Muscles for the Ultrasonographic Screening of Hip Abnormalities in Hip Resurfacing Arthroplasty Patients.

BACKGROUND: Hip resurfacing arthroplasty (HRA) patients require subsequent annual screening for postoperative complications. Ultrasonography may be useful for this purpose but lacks a screening protocol for hips. The purpose of this study was to evaluate the accuracy of ultrasonography for detecting postoperative complications in HRA patients using a screening protocol that specifically targets periprosthetic muscles. METHODS: We enrolled 45 hips from 40 HRA patients with a mean follow-up period of 8.2 years. MRI and ultrasonography scans were simultaneously conducted at follow-up. The ultrasonography assessments were conducted on the anterior part of the hip that targets iliopsoas, sartorius, rectus femoris, lateral with anterior superior and inferior iliac spine (ASIS and AIIS) as bony landmarks, and the lateral and posterior parts that target fascia tensor, short rotators, and gluteus minimus, medius, and maximus with greater trochanter and ischial tuberosity as bony landmarks. The accuracy of diagnosing postoperative abnormalities and the visibility of periprosthetic muscles were compared between these two modalities. RESULTS: Both MRI and ultrasonography detected an abnormal region in eight cases comprising two infections, two pseudotumors, and four patients with greater trochanteric bursitis. Among these cases, four hips required implant removal. The increase in anterior space, measured as the distance between the iliopsoas and resurfacing head, was a good indicator for the abnormal mass in these four HRA cases. In the assessment of periprosthetic muscles, MRI showed a much lower visibility than ultrasonography in the iliopsoas (6.7% vs. 100%), gluteus minimus (6.7% vs. 88.9%), and short rotators (8.8% vs. 71.4%) due to implant halation. CONCLUSIONS: By targeting periprosthetic muscles, ultrasonography can detect postoperative complications as effectively as MRI assessments in HRA patients. Ultrasonography has superior visibility in the periprosthetic muscles of HRA patients, indicating its utility for the screening of small legions in these cases which may not be visible by MRI.

Reliability and validity of ultrasonographic automated length measurement system for assessing talofibular anterior instability in acute lateral ankle sprain.

Ankle joint instability after acute lateral ankle sprain (LAS) is an important factor for deciding treatment strategies. Nevertheless, the degree of ankle joint mechanical instability as a criterion for making clinical decisions is unclear. This study examined the reliability and validity of an Automated Length Measurement System (ALMS) in ultrasonography for assessing real-time anterior talofibular distance. Using a phantom model, we tested whether ALMS could detect two points within a landmark following movement of the ultrasonographic probe. Furthermore, we examined whether ALMS was comparable with the manual measurement method for 21 patients with an acute LAS (42 ankles) during the reverse anterior drawer test. Using the phantom model, ALMS measurements showed excellent reliability, with errors below 0.4 mm and with a small variance. The ALMS measurement was comparable to manually measured values (ICC = 0.53-0.71, p < 0.001) and detected differences in talofibular joint distances between unaffected and affected ankles of 1.41 mm (p < 0.001). ALMS shortened the measurement time by one-thirteenth for one sample compared to the manual measurement (p < 0.001). ALMS could be used to standardize and simplify ultrasonographic measurement methods for dynamic joint movements without human error in clinical applications.

Medial meniscus extrusion and stage are related to the size of spontaneous osteonecrosis of the knee in patients who underwent high tibial osteotomy.

PURPOSE: Spontaneous osteonecrosis of the knee (SONK) causes acute atraumatic knee pain, and meniscus tears may be associated with the pathogenesis of SONK. The purpose of this study was to investigate the relationship of the type of meniscus tear and medial meniscus extrusion with SONK on the medial femoral condyle in patients who underwent surgical treatment with high tibial osteotomy due to severe knee pain. METHODS: We enrolled 98 patients with 102 knees who underwent medial opening wedge high tibial osteotomy (OWHTO) under the diagnosis of medial femoral condyle osteonecrosis at our hospital from December 2003 to January 2020. Based on the Koshino classification, cases of SONK were classified as stage 1-4. The relationships of demographic data, X-rays and MRI images, including femorotibial angle (FTA), meniscus tear type, and medial meniscus extrusion (MME), with the stage and volume of SONK were investigated. RESULTS: Ninety-eight patients (29 males and 69 females), with an average age at surgery of 69.2 ± 9.6 years and Body mass index(BMI) of 61.0 ± 17.6 kg/m2. In 102 cases of SONK, 11 knees, 18 knees, 46 knees, and 27 knees were classified as stage 1-4, respectively. The mean SONK volume was 2161.61 µm (range 95.67-7484.68 µm) on preoperative MRI. The preoperative FTA (mean 180.86°, range 172-187°) was not associated with the stage or volume of SONK. Meniscus tears were found in all cases of SONK and consisted of 2 degenerations, 2 horizontal tears, 0 vertical tears, 40 radial tears, 4 complex tears, and 54 medial meniscus posterior root tears (MMPRTs). In addition, 99% (101/102) of knees showed more than 3 mm of meniscus extrusion. Although the meniscus tear type was not associated with SONK stage, there was a high rate of tears that caused disruption of the hoop strain, such as MMPRTs (52.9%) or radial tears (39.2%). MME was significantly related to SONK volume (r = 0.387, p < 0.001). CONCLUSION: All patients with SONK had coexisting meniscus tears, most menisci had medial extrusion, and a positive correlation was observed between MME and SONK volume.

Ultrasonographic prevalence of ulnar nerve displacement at the elbow in young baseball players.

BACKGROUND: Overhead-throwing athletes are at risk of elbow injury because of valgus stress, leading to unstable ulnar nerves and neuropathy. Studies regarding ulnar nerve damage/displacement have been performed primarily in adults. OBJECTIVE: To determine the prevalence and related factors associated with ulnar nerve displacement at the elbow in young baseball players. DESIGN: Cross-sectional study. PARTICIPANTS: Youth baseball players ages 10-12 years were eligible to participate. Exclusion criteria were history of neuropathic pain, trauma, or prior surgery of the upper limb. Fifty-seven participants were eligible for inclusion in the study. MAIN OUTCOME MEASUREMENTS: Demographic data and ultrasonography findings of ulnar nerve dynamics at the cubital tunnel were analyzed in a total of 114 elbows. Elbows were grouped into nondislocation and displacement (subluxation or dislocation) groups according to ultrasound findings. Logistic generalized estimating equations were used to identify factors associated with ulnar nerve displacement. RESULTS: Thirty-six (31.6%) elbows demonstrated sonographic findings of ulnar nerve displacement, with 13 (11.4%) subluxations and 23 (20.2%) dislocations. Fourteen (24.6%) participants experienced nerve displacement in the dominant elbow only, whereas nerve displacement in both elbows occurred in 11 (19.3%) participants. Nerve displacement in the nondominant elbow only was not observed. Hand dominance and tenderness of the arcade of Struthers' were factors associated with ulnar nerve displacement (odds ratio, 2.81, and 9.73; 95% confidence interval, 1.34-5.91 and 2.45-38.68; p = .006 and .001, respectively). CONCLUSION: One-third of the young baseball players evaluated had ultrasonographic findings compatible with ulnar nerve displacement at the elbow. Hand dominance and tenderness of Struthers arcade were the only factors associated with ulnar nerve displacement. Ultrasound may help identify patients with ulnar nerve displacement and contribute to the understanding of its pathophysiology in young baseball players.

Return to sports activity after opening wedge high tibial osteotomy in patients aged 70 years and older.

BACKGROUND: The purpose of this study was to evaluate return to sports (RTS) after opening wedge high tibial osteotomy (OWHTO) in elderly patients and associated factors affecting RTS. METHODS: Seventy-four patients (mean age 68 years) who underwent OWHTO were enrolled. Clinical outcomes were evaluated using the Knee Society Score (KSS). Patients were asked regarding types of sports activities and their levels of participation within preoperative 1 year and postoperative 1 year. Levels of participation in sports and recreational activities were examined using the Tegner activity scale. The outcomes were compared between two age groups (≥ 70 years vs. < 70 years). RESULTS: Of the 74 patients overall, 59 participated in at least one sport preoperatively, and 55 returned to sports postoperatively (RTS 93%). The KSS knee score and function score were significantly improved after surgery in both age groups (P < 0.05), but no significant differences were found between the age groups. The Tegner activity scales for ≥ 70 years and < 70 years were 2.9 ± 1.1 and 4.0 ± 1.9 preoperatively (P < 0.01) and 2.7 ± 1.2 and 3.3 ± 1.4 postoperatively (P = 0.16), respectively. RTS was reported by 24 of 25 (96.0%) in the age < 70 years group and 31 of 34 (91.2%) in the age ≥ 70 years group. Majority of age ≥ 70 years participated in low-impact sports preoperatively and returned to the same impact level postoperatively. CONCLUSIONS: The rate of RTS after OWHTO was high in patients aged 70 years and older with low-impact level. OWHTO is a preferred surgical option for elderly patients who desire RTS.

Sclerostin inhibits interleukin-1ß-induced late stage chondrogenic differentiation through downregulation of Wnt/ß-catenin signaling pathway.

It is known that Wnt/ß-catenin signaling induces endochondral ossification and plays a significant role in the pathophysiology of osteoarthritis (OA). Sclerostin is a potent inhibitor of the Wnt/ß-catenin signaling pathway. This study investigated the role of sclerostin in the endochondral differentiation under an OA-like condition induced by proinflammatory cytokines. ATDC5 cells were used to investigate chondrogenic differentiation and terminal calcification, and 10 ng/ml IL-1ß and/or 200 ng/ml sclerostin were added to the culture medium. IL-1ß impaired early chondrogenesis from undifferentiated state into proliferative chondrocytes, and it was not altered by sclerostin. IL-1ß induced progression of chondrogenic differentiation in the late stage and promoted terminal calcification. These processes were inhibited by sclerostin and chondrogenic phenotype was restored. In addition, sclerostin restored IL-1ß-induced upregulation of Wnt/ß-catenin signaling in the late stage. This study provides insights into the possible role of sclerostin in the chondrogenic differentiation under the IL-1ß-induced OA-like environment. Suppression of Wnt signaling by an antagonist may play a key role in the maintenance of articular homeostasis and has a potential to prevent the progression of OA. Thus, sclerostin is a candidate treatment option for OA.

Platelet-Rich Plasma Promotes Migration, Proliferation, and the Gene Expression of Scleraxis and Vascular Endothelial Growth Factor in Paratenon-Derived Cells In Vitro.

BACKGROUND:: Platelet-rich plasma (PRP) is a treatment option for tendon injury because of its effective tendon-healing properties. At the early stage of tendon repair, paratenon-derived cells (PDCs) are thought to play a more important role than tendon proper-derived cells (TDCs). However, there has been no study investigating the effects of PRP on PDCs. HYPOTHESIS:: PRP promotes the migration, proliferation, and differentiation of PDCs in vitro. STUDY DESIGN:: Controlled laboratory study. METHODS:: TDCs and PDCs were isolated from the tendon proper and paratenon of rat Achilles tendons and were cultured to the third passage. PRP was prepared from the rats using the double-spin method. Third-passage TDCs and PDCs were cultured in Dulbecco's modified Eagle medium with 2% fetal bovine serum (control group) or 2% fetal bovine serum plus 5% PRP (PRP group), and cell migration, proliferation, and differentiation were evaluated. The relative mRNA expression levels of scleraxis (Scx), tenomodulin (Tnmd), collagen type I alpha 1 (Col1a1), collagen type III alpha 1 (Col3a1), and vascular endothelial growth factor A (VEGF) were examined by quantitative real-time reverse transcription polymerase chain reaction. RESULTS:: The cell migration rate was significantly higher in the PDCs of the PRP group than in the control group (1.4-fold increase; P = 0.02). Cell proliferation was significantly higher in the PDCs of the PRP group (2.2-fold increase; P < 0.01). In the PDCs, the gene expression levels of Scx, Col1a1, and VEGF were significantly increased by PRP (Scx: 2.0-fold increase, P = 0.01; Col1a1: 5.3-fold increase, P = 0.01; VEGF: 7.8-fold increase, P = 0.01), but the gene expression level of Tnmd, a factor for tendon maturation, was significantly reduced by PRP (0.11-fold decrease; P = 0.02). CONCLUSION:: In vitro PRP promoted migration, proliferation, and tenogenic differentiation with the upregulation of Scx in PDCs. PRP also upregulated the expression of the angiogenic marker VEGF. CLINICAL RELEVANCE:: Our results suggest that PRP treatment in vitro may enhance the tendon-healing properties of PDCs at the initial stage of tendon repair.

Sclerostin is upregulated in the early stage of chondrogenic differentiation, but not required in endochondral ossification in vitro.

Sclerostin is a potent inhibitor of the canonical Wnt signaling pathway. Wnt signaling pathways have multiple roles in the regulation of cartilage development, growth, and maintenance. This study focused on the role of sclerostin in the process of chondrogenic differentiation. We hypothesized that sclerostin is essential to induce chondrogenic differentiation and regulate endochondral ossification. ATDC5 cells were used to investigate chondrogenic differentiation and terminal calcification. During chondrogenic differentiation, intrinsic sclerostin was upregulated in the early stage, but downregulated in the late stage. Addition of sclerostin elevated expressions of Sox9 and Col2a1 (P<0.05) and reduced expressions of Runx2, Col10a1, MMP-3, MMP-13, and ADAMTS5 (P<0.05) through inhibition of the Wnt-ß-catenin signaling pathway (P<0.05). Terminal calcification was significantly inhibited by sclerostin (P<0.05). In contrast, deletion of sclerostin decreased expressions of Sox9 and Col2a1 (P<0.05), increased expressions of Runx2, Col10a1, MMP-3, and MMP-13 (P<0.05), and promoted terminal calcification (P<0.05). This study provides insights into the possible role of sclerostin in the regulation of chondrogenic differentiation. Sclerostin is upregulated in the early stage of chondrogenic differentiation, but is not required in endochondral ossification. Sclerostin is a candidate modulator for chondrogenic differentiation.

Effect of Low-Intensity Pulsed Ultrasound (LIPUS) on Endochondral Ossification via the Wnt Signaling Pathway.

OBJECTIVE: We have previously demonstrated that LIPUS stimulates endochondral ossification with decreased expression of sclerostin. The Wnt signaling pathway was examined in vitro to further address the effect of LIPUS on endochondral ossification. MATERIALS AND METHODS: ATDC5 cells were plated at an initial density of 6 × 10 cells/well in a 6-multiwell plate and cultured in the presence of 5% FBS plus ITS. The bottom of the culture plate was treated every day with LIPUS for 20 minutes. The level of calcification and the expression of Wnt signaling were investigated. RESULTS: The area of calcified nodules in the LIPUS-treated group was significantly greater than in the control group. The expression of Wnt was significantly elevated by LIPUS exposure. Markers associated with endochondral ossification were increased in the LIPUS-treated group. When sclerostin was added to the culture media, calcified nodule formation and the expression of Wnt were inhibited in both the LIPUS-treated group and the control group. DISCUSSION: This study suggests that endochondral ossification was stimulated by LIPUS via the Wnt signaling pathway.