Evaluation of skeletal muscle metabolism during walking in symptomatic and asymptomatic patients with osteoarthritis of the knee joint using positron emission tomography.

Background: This study aimed to evaluate skeletal muscle metabolism during walking in symptomatic and asymptomatic patients with knee osteoarthritis using positron emission tomography-computed tomography with 18F-fluorodeoxyglucose. We hypothesized that quadriceps muscle metabolism during walking would vary between the groups.

Methods: Twenty-two participants (11 males and 11 females) with knee osteoarthritis (Kellgren-Lawrence grade 2) were divided into symptomatic and asymptomatic groups.

Preoperative magnetic resonance imaging of lateral meniscus extrusion likely indicates posterior root tear in anterior cruciate ligament-injured knees.

Background: A lateral meniscal posterior root tear (LMPRT) is a known complication of anterior cruciate ligament (ACL) injury. Complete repair of meniscal posterior root tears is essential for preventing degenerative changes in the knee that may result from meniscal extrusion and rotational instability. This study aimed to assess the relationship between LMPRT morphology and preoperative lateral meniscal extrusion (LME) and to determine the cutoff value for complete LMPRT based on preoperative LME measurements.

Histological evaluation of medial collateral ligament bursa injection, a new conservative treatment, in a rabbit model of medial meniscus horizontal tear.

Background: The ultrasound-guided medial collateral ligament bursa injection technique is safe, reproducible, and effective in treating symptomatic degenerative medial meniscal tears. However, the mechanisms of action and optimal drug combinations remain unclear. This study aimed to evaluate and compare the histological changes caused by injections of corticosteroids and hyaluronic acid into the medial collateral ligament bursa in a rabbit model of medial meniscus horizontal tears.

Knee flexor strength at 6 months after anterior cruciate ligament reconstruction using hamstring tendon can be predicted from that at 3 months.

Purpose: This study aimed to identify factors influencing persistent muscle weakness in knee flexor strength after anterior cruciate ligament (ACL) reconstruction using the hamstring tendon and establish a clear cut-off value at 3 months postoperatively for the limb symmetry index (LSI) to exceed 90% at 6 months postoperatively.

Methods: One hundred forty-eight patients undergoing ACL reconstruction were included and categorised into two groups based on knee flexor strength at 6 months postoperatively: patients with LSI of 90% or greater (achieved group: n = 114) and patients with LSI less than 85% (nonachieved group: n = 34). Items with significant differences between the two groups (preoperative waiting period, LSI to body weight ratio of knee flexor and extensor strength at 3 months postoperatively and peak torque angle of knee flexor muscle) were included in the multiple logistic regression analysis.

Identifying unstable ramp lesions using ultrasonography.

Background: Patients with suspected ramp lesions on magnetic resonance imaging (MRI) or ultrasonography (US) healed and showed no instability based on intraoperative arthroscopic findings. The purpose of this study was to assess the use of US in evaluating ramp lesions preoperatively and intraoperatively.

Methods: Eighty-two knees that underwent anterior cruciate ligament (ACL) reconstruction between January 2022 and June 2023 were included to assess the ramp lesion complication rate and instability using arthroscopic findings.

Periarticular cocktail injection is more useful than nerve blocks for pain management after anterior cruciate ligament reconstruction.

Background: Anterior cruciate ligament (ACL) reconstruction is commonly associated with moderate-to-severe postoperative pain. Notably, various pain control strategies, a femoral nerve block (FNB) with a lateral femoral cutaneous nerve block (LFCNB), adductor canal block (ACB) with LFCNB, or periarticular cocktail injection (PI), have been investigated. However, no studies compare the effects of FNB with LFCNB, ACB with LFCNB, and PI for pain control after ACL reconstruction.

Limited preoperative knee extension in anterior cruciate ligament reconstruction using a hamstring tendon affects improvement of postoperative knee extensor strength.

Purpose: This study aimed to determine the factors affecting knee extensor strength 6 months after anterior cruciate ligament (ACL) reconstruction using autograft hamstring tendon.

Methods: 144 patients who could undergo regular follow-up after ACL reconstruction were divided into 2 groups: those with greater than 90% (Group A: n = 95) and less than 85% (Group B: n = 49) isokinetic knee contraction at 60°/s 6 months post-ACL reconstruction. Basic information, injury status, limited preoperative knee extension, and knee extensor strength at 3 and 6 months postoperatively were compared between the groups.

The use of ultrasonography as an effective screening tool for chronic posterior cruciate ligament injuries.

Purpose: We aimed to explore the applicability and validity of ultrasonography for diagnosing chronic posterior cruciate ligament (PCL) injuries.

Methods: PCL thickness was measured at 2 cm proximal to the tibia insertion site. Using the same ultrasonography image, the angle tangent to the PCL from the tibia insertion site was also measured.

Extrusion of the medial meniscus under a weight-loading condition in early knee osteoarthritis: an investigation using special upright magnetic resonance imaging.

Background: Whether the medial meniscus morphology and movement occur under upright loading conditions in early knee osteoarthritis (OA) or medial meniscus posterior root tear (MMPRT) remains unknown. This study aimed to evaluate the medial and anteroposterior extrusion of the medial meniscus under unloaded and upright-loaded conditions in patients with early knee OA.

Methods: Twelve patients with early knee OA and 18 healthy adult volunteers participated in this study.

Outcome comparison of femoral nerve block and adductor canal block during anterior cruciate ligament reconstruction: adductor canal block may cause an unexpected decrease in knee flexor strength at 6 months postoperatively.

Introduction: Peripheral nerve blocks are frequently used in anterior cruciate ligament (ACL) reconstruction. While femoral nerve block (FNB) has been associated with knee extensor strength reduction in the early postoperative period, no consistent view of knee extensor strength several months after ACL reconstruction exists. This study aimed to compare the impact of intraoperative FNB and adductor canal block (ACB) during ACL reconstruction on knee extensor strength at 3 and 6 months postoperatively.

Speed whip ripstop technique during anterior cruciate ligament reconstruction using quadriceps tendon results in higher fixation strength.

Purpose: To compare the biomechanical strength of different fixation configurations using a suspensory button in a soft-tissue quadriceps tendon graft for Anterior Cruciate Ligament (ACL) reconstruction.

Methods: Thirty fresh-frozen bovine Achilles tendons (10 mm wide, 50 mm long, and 4 mm thick) were used in this study. Tendons were assigned to three groups (n = 10 per group) with different suture configurations using adjustable loops with a suspensory button: group A, with the threads of an adjustable loop fixed by crossing at the tip of the loop and the entire loop; group B, continuous loops with hanging buttons were directly sutured to the tendon with eight simple sutures; group C, fixation was performed using the speed whip ripstop technique.

Non-use of intra-articular drain after anterior cruciate ligament reconstruction does not affect postoperative knee pain and muscle strength on early period.

Introduction: This study aimed to determine the effect of using an intra-articular drain after anterior cruciate ligament (ACL) reconstruction on early postoperative pain, range of motion (ROM), muscle strength, and complications.

Materials And Methods: Between 2017 and 2020, of the 200 consecutive patients who underwent anatomical single-bundle ACL reconstruction, 128 patients underwent primary ACL reconstruction with hamstring tendons and were evaluated for postoperative pain and muscle strength at 3 months postoperatively. Sixty-eight patients who received intra-articular drain before April 2019 were classified as group D and 60 patients without an intra-articular drain after ACL reconstruction after May 2019 were classified as group N.

Differences in collagen types in the semitendinosus, quadriceps, and patellar tendons: A report using samples from an 11-year-old patient.

Background: This study aimed to determine the differences in the proportions of types I and type III collagen in the semitendinosus tendon (ST), quadriceps tendon (QT), and patellar tendon (PT), which are frequently used as autografts for anterior cruciate ligament (ACL) reconstruction.

Methods: Orthopedic surgeons diagnosed habitual dislocation of the left patella and surgically treated an 11-year-old boy. Medial patellofemoral ligament reconstruction, medial patellar tibial ligament reconstruction, and arthroscopic lateral release were performed simultaneously.

Ultrasound-guided adductor canal block is superior to femoral nerve block for early postoperative pain relief after single-bundle anterior cruciate ligament reconstruction with hamstring autograft.

Purpose: This study aimed to compare the combination of a lateral femoral cutaneous nerve (LFCN) block with a femoral nerve block (FNB) and an adductor canal block (ACB) for postoperative pain control in patients undergoing anterior cruciate ligament (ACL) reconstruction with hamstring autograft.

Methods: A non-randomized, prospective, controlled clinical trial was conducted. The FNB and ACB groups consisted of 41 and 40 patients, respectively.

Relationship between anatomical injury site of rectus femoris muscle strain and time taken to return to play in Japanese professional soccer players.

Purpose: The rectus femoris has three myotendinous or myoaponeurosis junctions and causes three types of muscle strain anatomically. We aimed to investigate the anatomical injury site of the rectus femoris muscle strain in professional soccer players as well as the characteristic findings on magnetic resonance imaging (MRI) and to evaluate its relationship with the time taken to return to play at competition levels.

Methods: Thirteen Japanese professional soccer players who sustained injuries to the rectus femoris were included in this study.

Regeneration Using Adipose-Derived Stem Cell Sheets in a Rabbit Meniscal Defect Model Improves Tensile Strength and Load Distribution Function of the Meniscus at 12 Weeks.

Purpose: The purpose of this study was to evaluate the mechanical properties, such as the tensile strength and load distribution function, of the meniscus tissue regenerated using adipose-derived stem cell (ADSC) sheets in a rabbit meniscal defect model.

Methods: ADSC sheets were prepared from adipose tissue of rabbits. The anterior half of the medial meniscus was removed from both knees.

Ligamentization of the reconstructed ACL differs between the intraarticular and intraosseous regions: A quantitative assessment using UTE-T2* mapping.

Background: The purpose of this study was to prospectively observe the trends of ultrashort echo time (UTE)-T2* values for the intraarticular and intraosseous regions of reconstructed anterior cruciate ligaments from 6 to 12 months after anterior cruciate ligament reconstruction by using UTE-T2* mapping, and to investigate the changes and differences over time in each region.

Methods: Ten patients underwent UTE-T2* mapping of the operated knee at 6, 9, and 12 months after anterior cruciate ligament reconstruction. The UTE-T2* values of intraarticular and intraosseous regions of reconstructed anterior cruciate ligaments at 6, 9, and 12 months postoperatively were statistically compared.

Anatomical description and short-term follow up clinical results for ultrasound-guided injection of medial collateral ligament bursa: New conservative treatment option for symptomatic degenerative medial meniscus tear.

Background: In this study, we investigated newly developed ultrasound (US)-guided medial collateral ligament (MCL) bursa injection as a conservative therapy for symptomatic degenerative medial meniscal (MM) tears. We aimed to describe the anatomical target and precise technique of this injection, confirm its accuracy using fresh cadaveric knees, and then evaluate preliminary clinical outcomes.

Methods: Anatomical studies were performed on three fresh cadavers.