Superior Capsule Reconstruction for Irreparable Rotator Cuff Tears yields Good Clinical Outcomes for Patients With and Without Diabetes Mellitus.

PURPOSE: To compare the clinical outcomes after superior capsule reconstruction (SCR) for irreparable rotator cuff tears (RCTs) in patients with and without diabetes mellitus (DM). METHOD: Patients who underwent SCR using fascia lata autograft for irreparable RCTs between 2012 and 2020 with a minimum 2-year follow-up were divided into non-DM and DM groups. Propensity score matching was used to select controls matched for patients' characteristics. Only patients with HbA1c <8% were eligible. The Visual Analog Scale (VAS) for shoulder pain, American Shoulder and Elbow Surgeons (ASES) and Japanese Orthopaedic Association scores, and acromiohumeral distance were evaluated preoperatively and at 2 years postoperatively. Shoulder active range of motion (ROM) was evaluated preoperatively, at 6 months, 1 year, and 2 years postoperatively. Graft integrity and postoperative complications required additional surgery were evaluated. The Wilcoxon signed-rank test and Mann-Whitney U test were used to compare continuous variables. Pearson's chi-squared test and Fisher's exact test were used for categorical variables. The interaction between the postoperative period and ROM were analyzed by Friedman test and Wilcoxon rank sum test with Holm-Sidak post-hoc test. RESULTS: We studied 154 patients (non-DM, 130; DM, 24) who underwent SCR. After matching, 21 patients were selected in each group. All clinical outcomes significantly improved at 2 years (all P<0.05) in both groups. We found no significant differences in clinical outcomes and rates of patients who achieved minimal clinically important differences of VAS and ASES scores between the groups (P=0.10-1.0). The rates of graft tear (both 9.5%) and complications (non-DM, 4.8%; DM, 0%) were not significantly different (both P=1.0). CONCLUSION: SCR using fascia lata autograft for irreparable RCTs yields good clinical outcomes, including ROM, in patients with and without DM. No significant differences in postoperative outcomes were observed between the two groups. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

Structural and clinical outcomes after superior capsule reconstruction using an at least 6-mm-thick fascia lata autograft including the intermuscular septum.

BACKGROUND: Superior capsule reconstruction (SCR) is a viable treatment option for irreparable rotator cuff tears. However, graft tear rate is highly variable in the previous studies, and the impact of graft tears on clinical outcomes after arthroscopic SCR remains controversial. We aimed to investigate the graft tear rate, timing of graft tear, and the impact of graft tears on clinical outcomes after arthroscopic SCR using an at least 6-mm-thick fascia lata autograft including the intermuscular septum. METHODS: This retrospective multi-institutional study included 154 patients (79 women and 75 men; mean age, 69.9 yr; age range, 49-87 yr) with irreparable rotator cuff tears who underwent arthroscopic SCR using an at least 6-mm-thick fascia lata autograft including the intermuscular septum and completed a minimum 2-year follow-up. Postoperative graft integrity was evaluated by magnetic resonance imaging examinations performed at 3, 6, 12, and 24 mo after surgery. The presence of a full-thickness defect within the graft was diagnosed as a graft tear. In contrast, a graft without a full-thickness defect was diagnosed as a healed graft. We compared the following data between patients with and without graft tears: (1) baseline characteristics, (2) visual analog scale pain score, (3) Japanese Orthopaedic Association score, (4) American Shoulder and Elbow Surgeons shoulder score, and (5) active range of motion. RESULTS: The overall graft tear rate was 11.7% (18 of 154 patients). Of 18 graft tears, 14 (77.8%) occurred within 6 mo after SCR. Two additional graft tears were diagnosed at 12 mo postoperatively and another 2 at 24 mo after SCR. The visual analog scale, American Shoulder and Elbow Surgeons, and Japanese Orthopaedic Association scores improved significantly after SCR in both patients with and without graft tears (all P < .0001). However, patients with graft tears showed significantly inferior postoperative visual analog scale, American Shoulder and Elbow Surgeons, and Japanese Orthopaedic Association scores (1.9, 75.2, and 77.4, respectively) than those without graft tears (0.5, 93.1, and 92.3, respectively; all P < .01). CONCLUSIONS: The overall graft tear rate after arthroscopic SCR using an at least 6-mm-thick fascia lata autograft including the intermuscular septum was low (11.7%), relatively to that reported in previous studies. The majority of graft tears (77.8%) occurred within 6 mo after SCR. Graft healing was associated with more favorable clinical outcomes after SCR.

Postoperative graft integrity affects clinical outcomes after superior capsule reconstruction using fascia lata autograft in posterior-superior rotator cuff tears: a multicenter study.

BACKGROUND: Previous studies have postulated that graft thickness and graft healing may be important factors for optimizing clinical outcomes of superior capsule reconstruction (SCR) for patients with irreparable rotator cuff tears (RCTs). However, the relationship between postoperative graft integrity and clinical outcomes after SCR remains unclear. We aimed to assess the relationship between postoperative graft integrity, including graft thickness and size of graft tear, and clinical outcomes after SCR in patients with irreparable RCTs. METHODS: This retrospective multicenter study included 188 patients (86 women, 102 men; mean age, 69.2 years; range, 49-87 years) with irreparable RCTs who underwent arthroscopic SCR using fascia lata autografts. Using magnetic resonance imaging, the graft integrity was evaluated postoperatively at or after 1 year and was classified, according to Hasegawa's classification, into 4 categories: type I-II, intact graft of sufficient thickness; type III, thinned graft without discontinuity; type IV, presence of a minor discontinuity; and type V, presence of a major discontinuity. We compared (1) baseline characteristics, (2) visual analog scale (VAS) for pain, (3) American Shoulder and Elbow Surgeons (ASES) score, (4) active shoulder range of motion, and (5) acromiohumeral distance (AHD) among 4 groups based on postoperative graft integrity. RESULTS: Magnetic resonance imaging scans revealed 152 shoulders (80.9%) with type I-II graft, 13 (6.9%) with type III graft, 13 (6.9%) with type IV graft, and 10 (5.3%) with type V graft. VAS and ASES scores significantly improved after SCR in all graft types (P < .0001 to P = .02). However, shoulders with type V grafts had significantly inferior postoperative VAS and ASES scores compared to those with type I-II grafts (P = .001 and P < .0001, respectively). Shoulders without graft tears (types I-II and III) showed significant improvements in shoulder elevation and internal rotation after SCR (P < .0001 to P = .02). In contrast, shoulders with large graft tears (type V) showed no significant improvement in shoulder range of motion. Postoperative acromiohumeral distance significantly increased only in shoulders with type I-II grafts (P < .0001). CONCLUSION: Postoperative graft thickness and size of graft tear affected clinical and radiographic outcomes after SCR using a fascia lata autograft. Patients with large graft tears had significantly inferior postoperative clinical scores compared to those with intact grafts of sufficient thickness, although arthroscopic SCR provided pain relief even in patients with graft tears. Shoulders with intact grafts of sufficient thickness restored glenohumeral stability and showed better clinical outcomes than those with graft thinning or tears.

Does the timing of surgical intervention impact the clinical outcomes and overall duration of symptoms in frozen shoulder?

BACKGROUND: The optimal timing of arthroscopic capsular release in patients with frozen shoulder is controversial. Some surgeons delay surgery in the belief that early surgical intervention results in a poorer prognosis. However, whether early surgical intervention causes inferior clinical outcomes and a longer duration of symptoms in frozen shoulder remains unclear. The objective of this study was to compare the clinical outcomes and overall duration of symptoms in frozen shoulder between patients who underwent early surgical intervention and those subjected to late surgical intervention. Our hypotheses were that (1) early surgical intervention would provide significant improvement in symptoms but inferior clinical outcomes because of more severe synovitis compared with late surgical intervention and (2) early surgical intervention would shorten the overall duration of symptoms compared with late surgical intervention. METHODS: We reviewed 60 consecutive patients with frozen shoulder who underwent arthroscopic capsular release. We compared clinical outcomes and the overall duration of symptoms between 2 groups: Group I comprised 27 patients who underwent surgery <6 months after onset (mean, 3.8 months), whereas group II comprised 33 patients who underwent surgery ≥6 months after onset (mean, 11.1 months). The severity of glenohumeral synovitis at the time of surgery was evaluated. Patient-reported pain, shoulder function, and range of motion, as well as the presence of sleep disturbance, were assessed preoperatively and at 3 and 6 months after surgery. RESULTS: Both groups showed significant improvements in the visual analog scale pain score, Japanese Orthopaedic Association score, American Shoulder and Elbow Surgeons score, and prevalence of sleep disturbance after surgery (P < .001), although the glenohumeral synovitis score was significantly higher in group I than in group II (P < .0001). Forward flexion at 6 months after surgery was significantly greater in group I than in group II (P = .007). The overall duration of symptoms was shorter in group I than in group II (P < .0001). Neither the pain score, functional score, prevalence of sleep disturbance, nor postoperative recovery time differed between groups. CONCLUSIONS: Arthroscopic capsular release provided significant pain relief and improvement in shoulder function in patients with frozen shoulder regardless of the timing of surgery. Early surgical intervention might shorten the overall duration of symptoms in frozen shoulder and is not associated with inferior clinical outcomes when compared with late surgical intervention. Surgeons do not need to delay surgical intervention for patients who have intolerable pain and/or nocturnal pain with sleep disturbance.

Relationship between humeral retroversion and baseball positions during elementary and junior-high school.

BACKGROUND: Humeral retroversion is greater in the dominant shoulder than in the nondominant shoulder in baseball players. However, the effect of different baseball positions during childhood on humeral retroversion remains unknown. The purpose of this study was to investigate the following: (1) the relationship between humeral retroversion and baseball positions played during elementary and junior-high schools; (2) the association between humeral retroversion and the prevalence of pain during the medical checkup and self-reported history of injuries in the dominant shoulder or elbow. METHODS: We enrolled 149 male high-school baseball players who started playing baseball in elementary school. The subjects were classified into 3 groups according to their baseball positions in elementary and junior-high schools. All participants completed questionnaires regarding their current and past positions, current incidence and history of injuries in their shoulder or elbow joints, and the age they started playing baseball. Shoulder range of motion, humeral retroversion on ultrasonographic-assisted measurement, and the association between humeral retroversion and shoulder and elbow pain were evaluated. RESULTS: Humeral retroversion was significantly greater in the dominant shoulder than in the nondominant shoulder in all groups (P < .001). In addition, humeral retroversion in the dominant shoulder was significantly greater in players who were pitchers in both elementary and junior-high schools than in those who were fielders during both periods (96.2° and 89.4°, respectively; P = .02). Humeral retroversion in the dominant shoulder was positively correlated (P = .005, r = 0.23) with the length of career as a pitcher during elementary and junior-high schools. Humeral retroversion was not correlated with the prevalence of pain during the medical checkup or self-reported history of injuries in the dominant shoulder or elbow (P values ranging from 0.09-0.99). CONCLUSION: These results suggest that playing baseball as a pitcher during elementary school and junior-high school affects the increase in humeral retroversion in the dominant shoulder. Increased humeral retroversion in the dominant shoulder by repetitive throwing motion is an adaptive change, rather than a pathologic change.

Histologic changes during healing with autologous fascia lata graft after superior capsule reconstruction in rabbit model.

BACKGROUND: Superior capsule reconstruction (SCR) has been developed to improve shoulder function and relieve pain in the treatment of irreparable rotator cuff tears. Previous studies have reported that graft healing can enhance favorable outcomes after SCR. On the other hand, graft tears often lead to less desirable outcomes and sometimes require additional surgical procedures. However, the healing process underlying this remains unclear. In this study, we aimed to investigate histologic changes occurring during the healing process associated with autologous fascia lata graft after SCR in vivo. We hypothesized that (1) autologous fascia lata graft can regenerate the fibrocartilaginous insertion into both the greater tuberosity and superior glenoid and (2) the midsubstance of the grafted fascia gradually remodels into tendon- and/or ligament-like tissue after SCR. METHODS: Irreparable supraspinatus tendon defects were created in 24 mature Japanese white rabbits (age, 6 months; mean weight, 3.2 kg). Four weeks after creation of the defects, the right shoulders were subjected to SCR using autologous fascia lata grafts. The left shoulders were left untreated. Samples from the shoulders were harvested at 4, 8, 12, and 16 weeks after surgery to undergo histologic and immunohistochemical examinations. RESULTS: Macroscopically, we did not observe graft tears after SCR in our experiments. Histologically, the number of chondrocyte-like cells gradually increased, and the extracellular matrices around those cells contained glycosaminoglycan at the fascia-bone junction after SCR. The unmineralized fibrocartilage, mineralized fibrocartilage, and tidemark were observed 16 weeks after SCR. The distribution of type II collagen presented a pattern similar to that of a normal tendon and ligament insertion. The cells and collagen fiber gradually oriented parallelly to the long axis in the midsubstance of the grafted fascia lata. Additionally, type III collagen was replaced with type I collagen in the midsubstance of the grafted fascia lata after SCR. CONCLUSIONS: SCR using fascia lata autograft regenerated the fibrocartilaginous insertion at both the greater tuberosity and superior glenoid. The midsubstance of the grafted fascia gradually remodeled into tendon- and/or ligament-like tissue. These results suggest that the fascia lata autograft has the capacity for graft-to-bone healing and remodeling after SCR.

Biomechanical assessment of docking ulnar collateral ligament reconstruction after failed ulnar collateral ligament repair with suture augmentation.

BACKGROUND: Ulnar collateral ligament (UCL) repair with single-strand suture augmentation has been introduced as a viable surgical option for throwers with acute UCL tears. For the original single-strand suture augmentation construct, revision UCL reconstructions can be challenging owing to the bone loss at the site of anchor insertion in the center of the sublime tubercle. This biomechanical study assessed a small-diameter (1.5-mm) ulnar bone tunnel technique for double-strand suture-augmented UCL repair that may be more easily converted to salvage UCL reconstruction if necessary, as well as a salvage UCL reconstruction with a docking technique after a failed primary suture-augmented UCL repair. METHODS: In 7 fresh-frozen cadaveric upper extremities (mean age, 66.3 years), a custom shoulder testing system was used to simulate the late cocking phase of throwing. The elbow valgus opening angle was evaluated using a MicroScribe 3DLX device for sequentially increasing valgus torque (from 0.75 to 7.5 Nm in 0.75-Nm increments) at 90° of flexion. Valgus angular stiffness (in newton-meters per degree) was defined as the correlation of sequentially increasing valgus torque with the valgus opening angle through simple linear regression (slope of valgus torque - valgus opening angle curve). Four conditions were tested: intact elbow, distal UCL avulsion, primary UCL repair with double-strand suture augmentation using small-diameter bone tunnels, and subsequent docking UCL reconstruction in the same specimen. Load-to-failure tests were performed for primary UCL repair with double-strand suture augmentation and subsequent docking UCL reconstruction. RESULTS: With increasing elbow valgus torque, the valgus opening angle increased linearly in each condition (R2 ≥ 0.98, P < .001). Distal UCL avulsion resulted in significantly decreased angular stiffness compared with the intact UCL (P < .001). Both UCL repair with double-strand suture augmentation and subsequent UCL reconstruction showed significantly increased angular stiffness values compared with distal UCL avulsion (P < .001 and P < .001, respectively). On load-to-failure testing, there was no significant difference in stiffness, yield torque, and ultimate torque between the primary suture-augmented UCL repair and the subsequent UCL reconstruction (P = .11, P = .77, and P = .38, respectively). In all specimens undergoing the small-diameter ulnar bone tunnel technique for double-strand suture-augmented UCL repair, failure occurred by retear of the repaired ligament without causing an ulnar bone bridge fracture. CONCLUSION: Primary UCL repair with double-strand suture augmentation using small-diameter bone tunnels was able to restore valgus stability. When failure occurs, this technique retains enough cortical bone to permit subsequent docking UCL reconstruction.

Effects of periodontal treatment on the medical status of patients with type 2 diabetes mellitus: a pilot study.

BACKGROUND: Studies have demonstrated that periodontal disease is associated with the development of systemic complications in patients with type 2 diabetes mellitus (T2DM). The purpose of this pilot study was to investigate which markers among various systemic disease parameters are affected by periodontal treatment in patients with T2DM. METHODS: Twelve patients with T2DM were given oral hygiene instructions and subsequent subgingival scaling and root planing. The periodontal status was recorded, and blood and urine samples were taken to measure various parameters of glucose control and systemic status at baseline and 1 month following the periodontal treatment. Serum concentrations of tumor necrosis factor-α and high-sensitivity C-reactive protein were measured by enzyme-linked immunosorbent assay. RESULTS: After the periodontal treatment, the glycated hemoglobin value was significantly improved. The levels of urinary N-acetyl-ß-D-glucosaminidase and albumin, which are markers of renal dysfunction, also decreased significantly after treatment. Among the parameters measured in serum, the γ-glutamyl transpeptidase level, which is usually interpreted as a marker of liver dysfunction, was significantly reduced. The serum concentrations of tumor necrosis factor-α and high-sensitivity C-reactive protein were also significantly reduced by periodontal treatment. CONCLUSION: Within the limitations of this pilot study, periodontal treatment may be effective not only in improving metabolic control, but also in reducing the risk of diabetic kidney and liver disease in patients with T2DM.

Intra- and Inter-rater Agreement on Magnetic Resonance Imaging Evaluation of Rotator Cuff Integrity After Repair.

PURPOSE: To investigate the intra- and inter-rater agreement of magnetic resonance imaging (MRI) evaluations of rotator cuff integrity at 6 and 24 months after arthroscopic rotator cuff repair (ARCR). METHODS: Three shoulder surgeons reviewed 68 MRI scans from 34 patients who had undergone ARCR and MRI examination at both 6 and 24 months after surgery. Postoperative rotator cuff integrity was investigated by using Owen, Sugaya, and Hayashida classifications to determine whether the rotator cuff was intact or whether there was a partial-thickness retear or full-thickness retear and Burks score to assess tendon appearance. Multirater kappa statistics were used to measure intra- and inter-rater agreement. Kappa values were interpreted according to guidelines adapted from the work of Landis and Koch. RESULTS: All classifications had similar intra- and inter-rater agreement (κ = 0.14 to 0.67, 0.23 to 0.60, respectively), but no intra- or inter-rater agreement scored "excellent." Inter-rater agreement after ARCR was higher at 24 months (κ = 0.31 to 0.60) than at 6 months (κ = 0.23 to 0.44) in all evaluations. Reviewers identified full-thickness retears with a moderate to good degree of inter-rater agreement in all evaluations, at both 6 months (κ = 0.42 to 0.73) and 24 months (κ = 0.61 to 0.80) after ARCR. However, poor inter-rater agreement (κ = 0.13 to 0.19) was found in the identification of partial-thickness retears in all evaluations at 6 months after ARCR. CONCLUSIONS: Shoulder surgeons showed better intra- and inter-rater agreement in predicting full-thickness tears compared with partial-thickness tears. The inter-rater agreement at 24 months after ARCR was superior to that at 6 months in predicting not only full-thickness retear but also partial-thickness retear. MRI evaluation of rotator cuff integrity at 6 months after ARCR may be less reliable, regardless of which classification system is used. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Ultrasonic wave properties of human bone marrow in the femur and tibia.

Ultrasonic wave properties of human bone marrow obtained in the femur and tibia were measured using an ultrasound pulse technique. The measured frequency range was 4-10 MHz, and the temperature range was 30 °C-40 °C. The sound velocity was 1410 m/s, and the attenuation coefficient was 4.4 dB/cm at 36 °C (10 MHz). These values decreased with temperature. Site dependence and individual differences in elderly human bone marrow were negligible. The slopes of the attenuation coefficient were estimated by a power law. The values of the exponent n were 2.0 (30 °C-38 °C) and 2.3 (40 °C).

Transcription factor Mohawk and the pathogenesis of human anterior cruciate ligament degradation.

OBJECTIVE: To investigate the expression and function of Mohawk (MKX) in human adult anterior cruciate ligament (ACL) tissue and ligament cells from normal and osteoarthritis (OA)-affected knees. METHODS: Knee joints were obtained at autopsy (within 24-48 hours postmortem) from 13 donors with normal knees (mean ± SD age 36.9 ± 11.0 years), 16 donors with knee OA (age 79.7 ± 11.4 years), and 8 aging donors without knee OA (age 76.9 ± 12.9 years). All cartilage surfaces were graded macroscopically. MKX expression was analyzed by immunohistochemistry and quantitative polymerase chain reaction. ACL-derived cells were used to study regulation of MKX expression by interleukin-1ß (IL-1ß). MKX was knocked down with small interfering RNA (siRNA) to analyze the function of MKX in extracellular matrix (ECM) production and differentiation in ACL-derived cells. RESULTS: The expression of MKX was significantly decreased in ACL-derived cells from OA knees compared with normal knees. Consistent with this finding, immunohistochemistry analysis showed that MKX-positive cells were significantly reduced in ACL tissue from OA donors, in particular in cells located in disorientated fibers. In ACL-derived cells, IL-1ß strongly suppressed MKX expression and reduced expression of the ligament ECM genes COL1A1 and TNXB. In contrast, SOX9, a chondrocyte master transcription factor, was up-regulated by IL-1ß treatment. Importantly, knockdown of MKX expression with siRNA up-regulated SOX9 expression in ACL-derived cells, whereas the expression of COL1A1 and TNXB was reduced. CONCLUSION: Reduced expression of MKX is a feature of degenerated ACL in OA-affected joints, and this may be mediated in part by IL-1ß. MKX appears necessary to maintain the tissue-specific cellular differentiation status and ECM production in adult human tendons and ligaments.

Histopathological changes in the human posterior cruciate ligament during aging and osteoarthritis: correlations with anterior cruciate ligament and cartilage changes.

OBJECTIVES: To determine the histological patterns of posterior cruciate ligament (PCL) degeneration during aging and in relation to changes in articular cartilage and anterior cruciate ligament (ACL) across the entire adult age spectrum. METHODS: Human knee joints (n=120 from 65 donors) were processed within 72 h of postmortem. Articular cartilage surfaces were graded macroscopically. Each PCL was histologically evaluated for inflammation, mucinous changes, chondroid metaplasia, cystic changes and orientation of collagen fibres. The severity of PCL degeneration was classified as normal, mild, moderate or severe. PCL scores were compared to ACL and cartilage scores from the same knees. RESULTS: All knees had intact PCL. Histologically, 6% were normal, 76% showed mild, 12% moderate and 9% severe degeneration. Fibre disorientation was the most prevalent and severe change. Histological grades of PCL and ACL correlated, but significantly fewer PCL than ACL showed severe changes. There was a weaker correlation between aging and total histological PCL scores (R=0.26) compared to aging and ACL scores (R=0.42). ACL scores correlated with cartilage scores (R=0.54) while PCL scores increased with the severity of osteoarthritis from grades 0 to III but not between osteoarthritis grades III-IV (R=0.32). In knees with ruptured ACL, the PCL scores correlated with cartilage scores of the lateral compartment. CONCLUSIONS: PCL histopathological changes were less severe than in the ACL. PCL degeneration was associated with ACL and cartilage damage. The lack of correlation with age indicates independent pathways for PCL versus ACL degeneration.

Anterior cruciate ligament changes in the human knee joint in aging and osteoarthritis.

OBJECTIVE: The development and patterns of spontaneous age-related changes in the anterior cruciate ligament (ACL) and their relationship to articular cartilage degeneration are not well characterized. This study was undertaken to investigate the types and temporal sequence of age-related ACL changes and to determine their correlation with cartilage lesion patterns at all stages of osteoarthritis (OA) development in human knee joints without prior joint trauma. METHODS: Human knee joints (n = 120 from 65 donors ages 23-92) were obtained at autopsy, and ACLs and cartilage were graded macroscopically and histologically. Inflammation surrounding the ACL was assessed separately. RESULTS: Histologic ACL substance scores and ligament sheath inflammation scores increased with age. Collagen fiber disorganization was the earliest and most prevalent change. The severity of mucoid degeneration and chondroid metaplasia in the ACL increased with the development of cartilage lesions. A correlation between ACL degeneration and cartilage degeneration was observed, especially in the medial compartment of the knee joint. CONCLUSION: Our findings indicate that ACL degeneration is highly prevalent in knees with cartilage defects and may even precede cartilage changes. Hence, ACL deficiencies may not only be important in posttraumatic OA, but may also be a feature associated with knee OA pathogenesis in general.

Effects of Irradiation by Carbon Dioxide Laser Equipped With a Water Spray Function on Bone Formation in Rat Tibiae.

BACKGROUND/AIM: Irradiation of tissue with carbon dioxide (CO2) laser shows a characteristic thermal effect that causes vaporization of tissue in the target region. However, the thermal effect in places other than the target region induces tissue damage. Two methods are used: high reactive-level laser therapy (HLLT), aimed at surgical treatment, and low reactive-level laser therapy (LLLT), aimed at cell and tissue activation. In both, vaporization of tissue is induced by thermal damage. A water spray function may ameliorate thermal damage from CO2 laser irradiation. In this study, we irradiated CO2 laser on rat tibiae with or without a water spray function and examined the effects of this technique on bone metabolism. MATERIALS AND METHODS: Bone defects were created in rat tibiae by dental bur in a Bur group and by laser in laser irradiation groups with (Spray group) and without (Air group) water spray function. At 1 week postoperatively, histological analyses of tibiae were performed using hematoxylin and eosin staining, immunohistochemical staining (IHC) with anti-sclerostin antibody, and 3-dimensional (3D) observation using micro-computed tomography. RESULTS: Histological findings and 3D observation confirmed induction of new bone formation following laser irradiation in both the Air and Spray groups. No bone formation was seen in the Bur group. IHC revealed that the activity of osteocytes in the region of irradiated cortical bone was markedly impaired in the Air group, but osteocyte impairment was ameliorated in the Spray group and absent in the Bur group. CONCLUSION: The water spray function appears effective in reducing thermal damage to tissues irradiated by CO2 laser. CO2 lasers with water spray function may be useful in bone regeneration therapy.

Equivalent radiation exposure with robotic total hip replacement using a novel, fluoroscopic-guided (CT-free) system: case-control study versus manual technique.

Accurate and precise positioning of the acetabular cup remains a prevalent challenge in total hip arthroplasty (THA). Robotic assistance for THA has increased over the past decade due to the potential to improve the accuracy of implant placement. However, a common criticism of existing robotic systems is the requirement for preoperative computerized tomography (CT) scans. This additional imaging increases patient radiation exposure, as well as cost, and requires pin placement during surgery. The goal of this study was to analyze the radiation burden associated with a novel, CT-free robotic THA system compared to an unassisted manual THA approach (n = 100/arm). On average, the study cohort had a higher number of fluoroscopic images captured (7.5 vs. 4.3 images; p < 0.001), radiation dose (3.0 vs. 1.0 mGy; p < 0.001), and a longer duration of radiation exposure (18.8 vs. 6.3 s; p < 0.001), per procedure, than the control group. Additionally, no learning curve was detected by CUSUM analysis with respect to the number of fluoroscopic images taken during the adoption of the robotic THA system. While statistically significant, in comparison to published literature, the radiation exposure of the CT-free robotic THA system was comparable to that of unassisted manual THA approach and less than that of CT-based robotic approaches. Thus, the novel CT-free robotic system likely poses no clinically significant increase in radiation exposure to the patient compared to manual approaches.

Autophagy activation by rapamycin reduces severity of experimental osteoarthritis.

OBJECTIVES: Osteoarthritis is associated with cell death and extracellular matrix degradation in articular cartilage. Autophagy is an essential cellular homeostasis mechanism that was found to be deficient in ageing and osteoarthritic cartilage. This study determined whether pharmacological inhibition of the mammalian target of rapamycin (mTOR), a key inhibitor of autophagy, has disease-modifying activity in experimental osteoarthritis. METHODS: Experimental osteoarthritis was induced by transection of the medial meniscotibial ligament and the medial collateral ligament in 2-month-old C57Bl/6 mice (n=36). Rapamycin (1 mg/kg weight/day) (n=18 mice) or dimethyl sulphoxide vehicle control (n=18 mice) was administered intraperitoneally for 10 weeks. Histopathological changes in articular cartilage and synovium were examined by using semiquantitative scoring systems. Rapamycin effects on mTOR signalling, autophagy, cartilage homeostasis and inflammation were analysed by immunohistochemistry and immunofluorescence staining. RESULTS: Rapamycin affected the mTOR signalling pathway in mouse knee joints as indicated by the inhibition of ribosomal protein S6 phosphorylation, a target of mTOR and activation of LC3, a main marker of autophagy. The severity of cartilage degradation was significantly (p<0.01) reduced in the rapamycin-treated group compared with the control group and this was associated with a significant (p<0.05) decrease in synovitis. Rapamycin treatment also maintained cartilage cellularity and decreased ADAMTS-5 and interleukin-1ß expression in articular cartilage. CONCLUSIONS: These results suggest that rapamycin, at least in part by autophagy activation, reduces the severity of experimental osteoarthritis. Pharmacological activation of autophagy may be an effective therapeutic approach for osteoarthritis.

Structured three-dimensional co-culture of mesenchymal stem cells with meniscus cells promotes meniscal phenotype without hypertrophy.

Menisci play a crucial role in weight distribution, load bearing, shock absorption, lubrication, and nutrition of articular cartilage within the knee joint. Damage to the meniscus typically does not heal spontaneously due to its partial avascular nature. Partial or complete meniscectomy is a common clinical treatment of the defective meniscus. However, this procedure ultimately leads to osteoarthritis due to increased mechanical stress to the articular cartilage. Meniscus tissue engineering offers a promising solution for partial or complete meniscus deficiency. Mesenchymal stem cells (MSC) have the potential to differentiate into meniscal fibrochondrocyte as well as deliver trophic effects to the differentiated cells. This study tested the feasibility of using MSC co-cultured with mature meniscal cells (MC) for meniscus tissue engineering. Structured cell pellets were created using MC and MSC at varying ratios (100:0, 75:25, 50:50, 25:75, and 0:100) and cultured with or without transforming growth factor-beta 3 supplemented chondrogenic media for 21 days. The meniscal and hypertrophic gene expression, gross appearance and structure of the pellets, meniscus extracellular matrix (ECM), histology and immunohistochemistry of proteoglycan and collagen were evaluated. Co-culture of MC with MSC at 75:25 demonstrated highest levels of collagen type I and glycosaminoglycans (GAG) production, as well as the lowest levels of hypertrophic genes, such as COL10A1 and MMP13. All co-culture conditions showed better meniscus ECM production and hypertrophic inhibition as compared to MSC culture alone. The collagen fiber bundles observed in the co-cultures are important to produce heterogenic ECM structure of meniscus. In conclusion, co-culturing MC and MSC is a feasible and efficient approach to engineer meniscus tissue with enhanced ECM production without hypertrophy.

Relationship between the Hamada Grade and underlying pathological conditions in the rotator cuff and long head of biceps in symptomatic patients with rotator cuff tears.

Background: This study aimed to investigate the relationship between Hamada Grade and rotator cuff and long head of the biceps (LHB) pathologies in symptomatic patients with rotator cuff tears (RCTs). Methods: We retrospectively reviewed 376 patients (156 men and 220 women; mean age, 68.4 years) who had undergone surgery for complete RCTs. Preoperative plain radiography, magnetic resonance imaging, and intraoperative findings were assessed. All cases were allocated to the Hamada Grade 1, 2, 3, and 4-5 groups to investigate the correlation between Hamada Grade severity and underlying rotator cuff and LHB pathologies. Results: The rate of RCTs involving the infraspinatus was significantly higher in Grade 2 than in Grade 1 (P < .0001). The tear size and fatty muscle degeneration of the subscapularis in Hamada Grade 3 were significantly more severe than those in Grade 2 (P = .01 and P < .0001, respectively). The tear size and fatty muscle degeneration of the rotator cuff in Grade 4-5 were significantly more severe than those in Grade 3 (all P < .05). The complete LHB rupture rate was significantly higher in Hamada Grade 4-5 than in Grades 1, 2, and 3 (all P < .001). Conclusion: Rotator cuff tears involving the infraspinatus were associated with Hamada Grade 2. The rate of concomitant subscapularis tears with posterosuperior RCTs was significantly higher in Hamada Grade 3 than in Hamada Grade 2. RCT enlargement, progression of fatty muscle degeneration of the subscapularis and posterosuperior rotator cuff muscles, and the increase in complete LHB rupture were associated with Hamada Grade 4-5.