Protective Effects of Extracorporeal Shockwave Therapy on the Degenerated Meniscus in a Rat Model.

BACKGROUND: Loss of meniscal function in association with degenerative changes affects the development and progression of knee osteoarthritis, for which there is currently no effective treatment. Extracorporeal shockwave therapy (ESWT) is an established treatment for musculoskeletal disorders. However, the therapeutic effect of ESWT on meniscal degeneration remains unclear. PURPOSE: To evaluate the therapeutic effect of ESWT on the degenerated meniscus in an anterior cruciate ligament transection (ACLT) model. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve-week-old male Wistar rats were randomly assigned to 3 groups (normal, ESWT-, and ESWT+). Unilateral ACLT of the right knee was performed in the latter 2 groups. At 4 weeks after ACLT, the ESWT+ group received 800 shockwave impulses at an energy flux density of 0.22 mJ/mm2 in a single session. Histological changes were examined in the posterior portion of the medial meniscus after ESWT (n = 15 per group). Real-time polymerase chain reaction (PCR) was performed after ESWT (n = 5 per group) to analyze the expression of connective tissue growth factor/CCN family member 2 (CTGF/CCN2), sex determining region Y-box 9, vascular endothelial growth factor α, aggrecan, collagen type 1 alpha 2, and collagen type 2 alpha 1 (Col2α1). Immunohistochemistry was used to analyze the expression of CTGF/CCN2 and Ki-67 (n = 5 per group) after ESWT. RESULTS: The meniscal histopathological score at 4 weeks after ACLT was significantly higher than that in the normal group, and the score in the ESWT+ group was significantly lower than that in the ESWT- group at 4 and 12 weeks after ESWT. Real-time PCR revealed that the mRNA expression of CTGF/CCN2 and Col2α1 decreased 4 weeks after ACLT. In the ESWT+ group, real-time PCR revealed that the mRNA expression of CTGF/CCN2 increased 24 hours after ESWT, and the expression of Col2α1 increased 4 weeks after ESWT (all significant data were P < .05). The ratio of CTGF/CCN2-positive cells and Ki67-positive cells was significantly higher in the ESWT+ group after ESWT. CONCLUSION: The present study revealed that ESWT might suppress ACLT-induced meniscal degeneration by stimulating cartilage repair factors and inducing collagen type 2. CLINICAL RELEVANCE: ESWT can be an effective treatment to protect the degenerated meniscus in a rat model of ACLT.

Postoperative Medial Tilting of the Joint Line and Preoperative Kinematics Influence Postoperative Medial Pivot Pattern Reproduction in Total Knee Arthroplasty.

Background: Reproducing the medial pivot pattern after total knee arthroplasty (TKA) is known to improve patient satisfaction. However, the factors affecting the postoperative medial pivot pattern in TKA are controversial. The purpose of this study was to examine the factors affecting the postoperative medial pivot pattern in posterior-stabilized TKA. Methods: This study involved 30 cases with knee osteoarthritis who underwent primary posterior-stabilized TKA. The preoperative and postoperative kinematics were measured using a computed tomography-free navigation system, and the patients were divided into the following 2 groups: the medial pivot pattern (MP) group and non-medial pivot pattern (non-MP) group. In addition, we measured each of the following angles on X-ray films (preoperative and postoperative femorotibial angle, hip-knee-ankle angle, mechanical lateral distal femoral angle, medial proximal tibial angle). We examine the factors affecting the postoperative medial pivot pattern. Results: There were 14 cases in the MP group and 16 cases in the non-MP group at the preoperative knee kinematic assessment and 17 cases in the MP group and 13 cases in the non-MP group at the postoperative knee kinematic assessment. The preoperative kinematic pattern was conserved after the surgery at a rate of 76.7%. The postoperative MP-group showed a significantly smaller preoperative femorotibial angle and hip-knee-ankle and a significantly smaller postoperative mechanical lateral distal femoral angle and medial proximal tibial angle in comparison to the postoperative non-MP group. Conclusions: Preoperative kinematics and postoperative mechanical lateral distal femoral angle and medial proximal tibial angle may be important factors that affect the postoperative medial pivot pattern.

Insufficient restoration of meniscal extrusion by transtibial pullout repair for medial meniscus posterior root tears.

PURPOSE: The long-term changes in the dynamics of the medial meniscus after transtibial pullout repair for medial meniscus posterior root tears (MMPRTs) are not completely understood. Thus, the aim of this study was to investigate the effects of transtibial pullout repair on MMPRTs and whether the effects would be sustained. METHODS: Nineteen knees with MMPRTs that were treated by trans-tibial pullout repair were enrolled in this study. Medial meniscus extrusion (MME) was measured by ultrasonography during knee extension (no weight-bearing with the knee at 0° extension: NW0°) and 90° flexion (no weight-bearing with the knee at 90° flexion: NW90°) with the patient in the supine position and with full weight-bearing (FW0°) preoperatively and at 3 and 12 months postoperatively. The clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score, Lysholm score, and International Knee Documentation Committee score. RESULTS: The difference in MME with NW0° was not statistically significant between the preoperative (3.4 ± 1.0 mm) and 12-month postoperative (3.7 ± 0.6 mm) time points. The MME with NW90° at 3 (2.1 ± 0.7 mm) and 12 months (2.9 ± 0.6 mm) postoperatively were significantly lower than the preoperative values (3.4 ± 0.8 mm) (P < 0.05). However, the value significantly increased from 3 to 12 months postoperatively (P < 0.05). The MME with FW0° at 12 months postoperatively (4.3 ± 0.6 mm) was significantly larger than that at pre-operatively (3.6 ± 0.9 mm) (P < 0.05). All the patients' clinical conditions were significantly improved at 12 months postoperatively when compared to their preoperative clinical conditions. CONCLUSION: Surgery did not reduce the extrusion in the no weight-bearing and weight-bearing positions at knee extension, and these values increased in the postoperative period. In addition, while the surgery reduced the extrusion in the knee flexion position, the restoration achieved by the surgery was not sustained in the long term. LEVEL OF EVIDENCE: Level IV.

Increased Bone Plug Depth From the Joint Increases Tunnel Enlargement in Anterior Cruciate Ligament Reconstruction Using Bone-Patellar Tendon-Bone Autograft With Suspensory Femoral Fixation.

Purpose: To determine a safe bone plug depth fixation zone based on early tunnel enlargement rates in anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone (BPTB) autograft with suspensory femoral fixation. Methods: Patients who had undergone rectangular tunnel ACL reconstruction using BPTB autograft with suspensory femoral fixation were retrospectively identified. Femoral and tibial tunnel aperture areas were measured on computed tomography 2 weeks and 6 months after surgery to calculate rates of femoral and tibial tunnel enlargement (FTE and TTE), respectively. Femoral bone plug depth (FBPD) and tibial bone plug depth (TBPD) were defined as the distance of the tip of the plug from the respective joint lines. Optimal FBPD and TBPD cutoff values were calculated for the following rates of FTE and TTE, respectively: 0%, 15%, 30%, and 50%. Results: Sixty-four patients (19 females, 45 males; mean age, 29.5 ± 12.3 years) were included in the study. The femoral and tibial tunnel apertures significantly enlarged over time. FBPD (P < .001; r = 0.607) and TBPD (P = .013; r = 0.308) were positively correlated with FTE and TTE, respectively. The optimal FBPD cutoff value was 2.8 mm for FTE rates of 0% and 15%, 3.6 mm for 30%, and 6.0 mm for 50%. The optimal TBPD cutoff value was 1.48 mm for a 0% TTE rate and 5.1 mm for those higher. The cutoff value specificities were lower for the tibial tunnel than the femoral tunnel for each tunnel enlargement rate. Conclusion: Early tunnel enlargement and bone plug depth were significantly correlated in bone the femoral and tibial tunnels. The degree of correlation was higher in the femoral tunnel. To minimize bone tunnel enlargement, the distal end of the femoral bone plug should be placed less than 2.8 mm from the tunnel aperture. Level of Evidence: Level IV, therapeutic case series.

The Relationship Between Edema and Body Functions in Patients With Chronic Kidney Disease: A Preliminary Study.

INTRODUCTION: Chronic kidney disease (CKD) is known to be a risk factor for falls. In addition, numerous factors such as impaired body balance and loss of muscle mass were reported as risk factors for falls. Patients with CKD often have edema in their lower extremes. In Japan, edema, as well as physical factors, are listed as fall assessment items. Little is known about the relation between body functions and edema in patients with CKD. Thus, we conducted a multivariate regression analysis to investigate the factors related to knee extension muscle strength and dynamic balance in motion (TUG). MATERIALS AND METHODS: Thirty patients with CKD participated in this study. The basic characteristics were sex, age, blood pressure, body mass index (BMI), and medications. The laboratory data were estimated glomerular filtration rate (eGFR), hemoglobin (Hb), and C-reactive protein (CRP). Edema and muscle mass was measured by using InBody S10 (Inbody Japan Inc., Tokyo, Japan). The balance function while standing at rest and motion was measured as the total trajectory length of the center of gravity and the index of postural stability (IPS) using a kinetogravicorder 7100 (Anima Inc., Tokyo, Japan). Dynamic balance was assessed by the timed up & go (TUG) test. Knee extension muscle strength was measured by the Micro Total Analysis System (µ-Tas) F-1 (Anima Inc., Tokyo, Japan) test. Nutritional assessment was measured by the geriatric nutritional risk index (GNRI). Activities of daily living were measured using the functional independence measure (FIM). We conducted a multivariate regression analysis to investigate the factors related to knee extension muscle strength and dynamic balance in motion. RESULTS: Extracellular water/total body water (ECW/TBW) was not significantly correlated with balance at rest and IPS. The ECW/TBW was associated with knee extension muscle strength, TUG, albumin (Alb), Hb, and GNRI with statistical significance. After adjusting for sex and age, knee extension muscle strength was associated with ECW/TBW and TUG (p=0.044). The TUG was also associated with ECW/TBW after being adjusted for age and sex (p=0.046).  Conclusion: Patients with CKD who have edema may have decreased knee extensor strength and body balance function. Investigation of knee extension muscle strength and the body balance test in addition to the presence of leg edema at the time of physical examination may help predict a functional decline in CKD patients.

The effects of romosozumab combined with active vitamin D3 on fracture healing in ovariectomized rats.

BACKGROUND: In this study, we investigated the potential acceleration of fracture healing and bone mineral density-increasing effects of romosozumab and active vitamin D3 combination therapy for fractures in ovariectomized rats. METHODS: Ovariectomy was performed on 40 24-week-old female Sprague-Dawley rats. After 8 weeks, the rats were subjected to periosteum removal and osteotomy of the femoral shaft followed by osteosynthesis with intramedullary nailing to create fracture models. The rats were then divided into four groups: C group (control), R group (receiving romosozumab at 25 mg/kg once a month via subcutaneous injection), VD group (receiving active vitamin D3 at 0.2 µg/kg twice a week via subcutaneous injection), and R + VD group. Further, 10 rats were included in a sham group. At 10 weeks after the intervention, both femurs were removed and blood samples were collected from all rats. Soft X-ray imaging was used to evaluate bone union, and microcomputed tomography (micro-CT) was used for bone morphometric evaluation. Toluidine blue staining was used for the histopathological evaluation of the undecalcified specimens, and bone turnover marker levels were measured using enzyme-linked immunosorbent assay. RESULTS: Bone morphometry analysis via micro-CT revealed increased mineral density of the trabecular bone in the R + VD group femurs, demonstrating the effectiveness of romosozumab plus active vitamin D3 combination therapy. However, there were no differences in bone union evaluated using soft X-ray imaging, indicating no acceleration of fracture healing. CONCLUSIONS: Although romosozumab and active vitamin D3 combination therapy increased trabecular bone volume, there was no evidence on its ability to accelerate fracture healing.

Deep Infrapatellar Bursitis in Preadolescent Baseball Players: A Cross-Sectional Study.

Background: Deep infrapatellar bursitis (DIB) has been detected in cases of Osgood-Schlatter disease (OSD). However, the clinical implications of DIB in the apophyseal stage, during the period when OSD has not yet developed, remain unclear. Purpose: To investigate the factors related to DIB in the apophyseal stage in preadolescent baseball players. Study Design: Cross-sectional study, Level of evidence, 3. Methods: The study participants were junior baseball players who participated in a medical checkup in 2020. We included knees in the apophyseal stage evaluated using ultrasonography, and classified them into the bursitis and no-bursitis groups using color-enhanced Doppler ultrasonography. We also investigated bone lesions of the tibial tuberosity, determined by fragmentation of the bone and irregularity of the ossification center. Demographic data, practice duration, pressure pain on tuberosity, pain while playing baseball (visual analog scale), heel-buttock distance (HBD), straight-leg raise angle, and range of hip internal and external rotation were evaluated. Group comparisons were performed using the Mann-Whitney U test and Fisher exact test, and a logistic regression analysis was performed. Results: A total of 261 knees (139 male players; age 10.5 ± 1.1 years) were included, 30 in the bursitis group and 231 in the no-bursitis group. Bone lesions were present in 4 knees in the bursitis group and in 32 knees in the no-bursitis group; there was no significant relationship between the presence of bone lesions and bursitis. Compared with the no-bursitis group, the bursitis group had a significantly longer practice duration (12.9 ± 3.3 vs 15.2 ± 3.8 hours/week, respectively; P = .003) and larger HBD (0.5 ± 1.3 vs 1.4 ± 2.4 cm, respectively; P = .003). The logistic regression analysis showed that practice duration (P = .001) and HBD (P = .004) were significantly related to the presence of bursitis. Conclusion: DIB in the apophyseal stage was related to practice duration and thigh muscle tightness. These findings may help predict overload and thigh muscle tightness at a very early stage.

Healing Status of Meniscal Ramp Lesion Affects Anterior Knee Stability After ACL Reconstruction.

BACKGROUND: Although the biomechanical importance of the ramp lesion in the anterior cruciate ligament (ACL)-deficient knee has been demonstrated, there is no clear consensus on the appropriate treatment for ramp lesions during ACL reconstruction. PURPOSE: To compare the postoperative outcomes for ramp lesions between patients treated with all-inside repair through the posteromedial portal and those whose ramp lesions were left in situ without repair during ACL reconstruction. We also determined whether ramp lesion healing status affected postoperative knee stability. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 57 patients who underwent anatomic double-bundle ACL reconstruction between August 2011 and December 2017 had attendant ramp lesions. Of these, 25 ramp lesions that were considered stable were left in situ without repair (Nonrepaired group), and 25 ramp lesions, including 21 stable and 4 unstable lesions, were treated using all-inside repair through the posteromedial portal (Repaired group). We evaluated the side-to-side difference (SSD) in anterior tibial translation on stress radiographs and rotational stability by using the pivot-shift test 2 years after surgery, and healing status of the ramp lesions was evaluated on 3.0-T magnetic resonance imaging (MRI) scans 1 year after surgery. RESULTS: The mean SSDs in anterior translation were 2.4 ± 1.6 mm for the Nonrepaired group and 1.9 ± 1.6 mm for the Repaired group, with no significant differences. The positive ratios on the pivot-shift test were not significantly different between groups. Healing rates of ramp lesions on MRI scans showed a significant difference between the Nonrepaired group (60%) and the Repaired group (100%) (P = .001). The mean SSDs for knees in which the ramp lesion had healed as shown on MRI scans and those in which it had not healed were 1.9 ± 1.6 mm and 3.2 ± 1.1 mm, respectively, which was a significant difference (P = .02). CONCLUSION: Healing rates of ramp lesions were significantly better in the Repaired group than in the Nonrepaired group, although postoperative knee stability was not significantly different between groups. Anterior laxity in the knees in which the ramp lesion was unhealed was significantly greater compared with the knees in which the ramp lesion healed. All-inside repair through the posteromedial portal was a reliable surgical procedure to heal ramp lesions.