Long-lasting decreased pain threshold negatively affects functional recovery after arthroscopic rotator cuff repair.

PURPOSE: The relationship between sensitization and postoperative function in patients undergoing arthroscopic rotator cuff repair (ARCR). The purpose of this study was to evaluate the effect of pre-and postoperative reductions in the pressure pain threshold (PPT) on postoperative clinical outcomes in patients with ARCR and investigate changes in PPT and clinical outcomes resulting from postoperative administration of weak opioids activating the central inhibitory system. METHODS: This retrospective study included patients who underwent primary ARCR, categorized into Group A (excellent/good Constant scores) and B (fair/poor Constant scores). In a complementary study, patients were randomized to the Control or Tramadol groups. Both studies evaluated the PPT, visual analog scale, active range of motion (ROM), Constant score, and retear rates pre-and postoperatively. RESULTS: In the primary study with 158 patients, those with poor clinical outcomes exhibited significantly lower PPT at the affected shoulder preoperatively at 3 months postoperatively compared to those with good outcomes. The PPT of the affected side was lower than that of the uninvolved side not only at 1 and 3 months but also preoperatively and at 6 months in the poor outcome group. In the secondary study involving 96 patients, weak opioid administration was associated with increased PPT for 3 months, improved ROM at 3 months postoperatively, and reduced postoperative pain 1 year postoperatively. CONCLUSION: Patients experiencing poor postoperative clinical outcomes exhibited prolonged lowered PPT. Lowered PPT due to sensitization may adversely affect functional recovery and pain perception. Elevating PPT using weak opioids improved clinical outcomes during the acute perioperative period after ARCR. LEVEL OF EVIDENCE: III.

Arthroscopic centralization reduces extrusion of the medial meniscus with posterior root defect in the ACL reconstructed knee.

PURPOSE: The purpose of this study was to evaluate the effects of arthroscopic meniscal centralization reinforcement for a medial meniscus (MM) posterior root defect on knee kinematics and meniscal extrusion in the anterior cruciate ligament reconstructed (ACLR) knee. The hypothesis was that the medial meniscus centralization would reduce extrusion and anterior laxity in ACLR knee with a medical meniscal defect. METHODS: Fourteen fresh-frozen human cadaveric knees were tested using a six-degrees-of-freedom robotic system under the following loading conditions: (a) an 89.0 N anterior tibial load, (b) 5.0 Nm internal and external rotational torques, (c) a 10.0 Nm valgus and varus loadings, and (d) a combined 7.0 Nm valgus moment and then a 5.0 Nm internal rotation torque as a static simulated pivot shift. The tested knee states included: (1) anatomic single-bundle cruciate ligament reconstruction with intact medial meniscus (MM Intact), (2) anatomic single-bundle cruciate ligament reconstruction with medial meniscus posterior root defect (MM Defect), (3) Anatomic single-bundle cruciate ligament reconstruction with medial meniscus arthroscopic centralization (MM Centralization). Medial meniscus arthroscopic centralization was performed using 1.4 mm anchors with #2 suture. The MM extrusion (MME) was measured using ultrasound under unloaded and varus loading conditions at 0° and 30° of flexion. RESULTS: Anterior tibial translation (ATT) increased significantly with MM posterior root defect compared to MM intact at all flexion angles. With MM centralization, ATT was not significantly different from the intact meniscus at 15° and 30° of flexion. Meniscus extrusion increased significantly with the root defect compared to intact meniscus and decreased significantly with meniscal centralization compared to the root defect at both flexion angles. CONCLUSIONS: In ACL reconstruction, cases involving irreparable medial meniscal posterior root tears, applying arthroscopic centralization for avoiding the meniscal extrusion should be considered. Clinically, in ACL reconstruction cases with irreparable medial meniscal posterior root tears, applying arthroscopic meniscal centralization for avoiding the meniscal extrusion should be considered. Meniscal centralization decreases the extrusion of the MM and offers improvements in knee laxity.

Anatomic restoration of the articular deep layer is a definitive factor for repair status in delaminated rotator cuff tear.

BACKGROUND: Recent studies have focused on the deep layer in delaminated rotator cuff tears. However, no studies have discussed the relationship between repair success and the properties of the deep layer. Herein, we aimed to analyze the intraoperative repair tension of the deep layer with respect to clinical outcomes and repair integrity and to evaluate the clinical results of delaminated rotator cuff tears after dual layer-specific repair. METHODS: A total of 202 patients with delaminated rotator cuff tears had undergone dual layer-specific suture bridge repair; the mean follow-up duration was 28.6 (24-72) months. Intraoperatively, the repair tension of the deep layer was measured using a tensiometer, and mobility was ranked as easy or tight. After repair of the deep layer, the superficial layer tension was measured and ranked in a similar fashion. Clinical outcomes were evaluated using the Constant score, American Shoulder and Elbow Surgeons score, and subjective shoulder values. The relationship between retear and intraoperative qualitative factors of tendons was investigated. Prognostic factors for retear were analyzed using multiple logistic regression analyses. RESULTS: Postoperative retears occurred in 11 (5.4%) patients. With regard to the deep layer, the tight mobility group had greater tear size, tendon retraction, and fatty infiltration of the supraspinatus and infraspinatus than the easy mobility group. No intergroup difference in postoperative retear rate was observed between the tight and easy deep-layer groups. Logistic regression analysis showed that fatty infiltration of the infraspinatus (odds ratio, 3.1; 95% confidence interval, 1.3-7.7; P = .013) and mobility of the superficial layer after deep layer repair (odds ratio, 8.1; 95% confidence interval, 1.7-38.1; P = .008) were predictors of retear. CONCLUSION: Intraoperative mobility in the deep layer was not directly related to postoperative retear. Conversely, the quality of the infraspinatus concomitant with mobility of the superficial layer after deep layer repair significantly influenced repair integrity. Good clinical results were obtained even in cases with high repair tension of the deep layer.

Effects of different surgical procedures for meniscus injury on two-year clinical and radiological outcomes after anterior cruciate ligament reconstructions. -TMDU MAKS study.

BACKGROUND: The treatment of meniscus injuries combined with anterior cruciate ligament (ACL) reconstruction would be important to improve outcomes after ACL reconstruction. However, the effects of treatment methods for meniscus after ACL reconstruction have not been thoroughly investigated. The objective of this study was to investigate the effects of treatment methods for meniscus on clinical and radiological outcomes at 2 years after ACL reconstruction. METHODS: Three-hundred and eighteen patients with primary ACL reconstruction using autologous hamstring tendon registered in our multicenter study database and who were followed up for 2 years were included. They were then divided into 3 groups, the no meniscal lesion/untreated group (n = 149), the meniscal repair group (n = 139), and the meniscal resection group (n = 30). Patient-based subjective evaluations (Lysholm score, Knee injury and Osteoarthritis Outcome score and International Knee Documentation Committee subjective score), objective evaluations (Lachman test, pivot shift test and KT measurement), and radiological measurements (medial and lateral joint space width) were compared among the 3 groups preoperatively and at 2 years follow-up. RESULTS: All subjective scores and objective evaluations significantly improved in all groups without significant differences among the groups postoperatively. Regarding radiological findings, the medial joint space width significantly decreased only in the resection group during the 2-year period, and the medial joint space width in the resection group was significantly smaller than that of the other groups at the 2-year follow-up. Moreover, the medial joint space width significantly decreased during the 2-year period when MM was resected. CONCLUSIONS: In radiological findings, medial meniscus resection decreased medial joint space width two years after ACL reconstruction. On the other hand, treatment methods for meniscus neither significantly affected subjective nor objective findings until the 2-year follow-up. LEVEL OF EVIDENCE: Ⅱ, Cohort study.

Low to moderate risk of nerve damage during peroneus longus tendon autograft harvest.

PURPOSE: This study aims to evaluate the proximity of the tendon stripper to both the peroneal and sural nerves during peroneus longus tendon (PLT) autograft harvesting. METHODS: Ten fresh-frozen human cadaveric lower extremities were used to harvest a full-thickness PLT autograft using a standard closed blunt-ended tendon stripper. The distance to the sural nerve from the PLT (at 0, 1, 2 and 3 cm proximal to lateral malleolus (LM), and the distance to the peroneal nerve and its branches from the end of the tendon stripper were measured by two separate observers using ImageJ software. RESULTS: The average distance from the PLT to the sural nerve increased significantly from 0 to 2 cm proximal to LM. The average distance to the sural nerve at the LM was 4.9 ± 1.5 mm and increased to 10.8 ± 2.4 mm (2 cm proximal to LM). The average distance from the tendon stripper to the deep peroneal nerve was 52.9 ± 11.4 mm. The average distance to the PLT branch of peroneal nerve was 29.3 ± 4.2 mm. The superficial peroneal nerve, which coursed parallel and deep to the tendon stripper, was on average 5.2 ± 0.7 mm from the end of the stripper. No transection injuries of the nerves were observed in any of the ten legs after harvesting. CONCLUSION: This cadaver study found during a full-thickness PLT harvest, the distances between the tendon stripper and the nerves were greater than 5 mm with an initial incision at 2 cm proximal to LM which is recommended.

Effect of transplanted mesenchymal stem cell number on the prevention of cartilage degeneration and pain reduction in a posttraumatic osteoarthritis rat model.

BACKGROUND: Mesenchymal stem cells (MSCs) transplantation therapy is considered an alternative therapy to prevent posttraumatic osteoarthritis (PTOA). However, consensus as to the sufficient number of MSCs for the prevention of PTOA is lacking. The purpose of this study was to determine the sufficient number of MSCs to achieve PTOA prevention and the reduction in pain after anterior cruciate ligament transection (ACLT). METHODS: Eight-week-old male Wistar rats were used. ACLT was conducted in the knee joint as a PTOA model. According to the species-specific knee joint volume, 104 MSCs in rats are equivalent to 3 × 107 MSCs in humans, which was clinically prepared. MSCs (104, 105, or 106 cells) or phosphate-buffered saline were injected into the knee joint at 1, 2, and 3 weeks after ACLT. Histological examinations were performed at 12 weeks after ACLT. The weight-bearing distribution improvement ratio was calculated as an assessment of pain until 12 weeks after ACLT. RESULTS: Histological evaluations showed that all the MSCs groups except for 104 MSCs group in femur were significantly improved compared to the control group at 12 weeks after ACLT. The weight-bearing distribution in the 104 and 105 MSCs groups at 12 weeks after ACLT and in the 106 MSCs group at 6, 8, 10, and 12 weeks after ACLT were significantly higher than those of the control group. CONCLUSION: A clinically feasible number of MSCs was found to reduce the articular cartilage degeneration and to decrease pain in the PTOA model. Increasing numbers of the cells further protected the articular cartilage against degeneration.

Contribution of Additional Anterolateral Structure Augmentation to Controlling Pivot Shift in Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Several types of anterolateral structure (ALS) augmentation procedures in anterior cruciate ligament (ACL) reconstruction have been reported. However, information is limited regarding the effect of additional ALS augmentation on rotatory stability in a clinical setting. PURPOSE/HYPOTHESIS: This study aimed to investigate the contribution of additional ALS augmentation in ACL reconstruction in cases with a high risk of residual pivot shift. The 2 hypotheses were as follows. First, additional ALS augmentation would improve rotatory stability as compared with solely reconstructing the ACL. Second, graft tension changes would be different between the ACL and ALS during knee range of motion and against anterior or rotatory loads. STUDY DESIGN: Controlled laboratory study. METHODS: Fifteen patients who met at least 1 of the following criteria were included: (1) revision ACL reconstruction, (2) preoperative high-grade pivot shift, or (3) hyperextended knee. The pivot-shift test was performed preoperatively and during surgery after ACL reconstruction and after additional ALS augmentation with acceleration measurements from a triaxial accelerometer. The tension changes of the ACL and ALS grafts were also measured during knee range of motion and against manual maximum anterior tibial translation, internal rotation, and external rotation. RESULTS: After ACL reconstruction, the pivot-shift acceleration was still greater than that of the uninjured knee. However, additional ALS augmentation further reduced acceleration when compared with ACL reconstruction alone in both primary and revision cases (P < .05 vs preoperative, P < .05 vs ACL). During knee flexion-extension, the tension of the ACL increased as the knee was extended, whereas that of the ALS did not change. Graft tension of the ACL and ALS became higher with internal rotation and lower with external rotation as compared with the neutral position. Tension of the ACL was significantly increased against anterior tibial translational loads, whereas that of the ALS was not. CONCLUSION: Additional ALS augmentation further improved the rotatory stability during ACL reconstruction in patients with a high risk of residual pivot shift at the time of surgery. Significant differences in graft tension changes were also observed between the ACL and ALS against different loads. Additional ALS augmentation may be considered to eliminate the pivot shift in patients with a high risk of residual pivot shift.

Effect of meniscus repair on pivot-shift during anterior cruciate ligament reconstruction: Objective evaluation using triaxial accelerometer.

BACKGROUND: Some types of meniscus tear, especially lateral meniscus tear, have been reported to be associated with rotatory knee laxity. However, precise information regarding the effect of meniscus repair on rotatory laxity is limited. The purpose of this study was to investigate the effects of lateral and medial meniscus repair on rotatory laxity in anterior cruciate ligament (ACL) injured knees. METHODS: Forty-one patients who underwent ACL reconstruction were included in the study. The tibial acceleration during the pivot shift test was measured using a triaxial accelerometer preoperatively under anesthesia and intraoperatively before and after medial and lateral meniscus repair and ACL reconstruction during surgery. Effects of meniscus tear and its repair on rotatory laxity were analyzed. RESULTS: Preoperative measurements revealed that patients with lateral meniscus tear showed significantly higher tibial acceleration compared to the patients without meniscus tear (P = 0.006). Intraoperative measurements revealed that medial and lateral meniscus repair significantly reduced tibial acceleration by 1.46 m/s2 (P = 0.002) and 1.91 m/s2 (P < 0.001), respectively. CONCLUSION: In ACL injured knees, knees with lateral meniscus tear showed greater rotatory laxity compared to the knees without meniscus tear. In addition, lateral meniscus repair, and to a lesser degree medial meniscus repair, reduced rotatory laxity during ACL reconstruction surgery. Therefore, the meniscus should be repaired as much as possible for its role as a secondary stabilizer of rotatory laxity. Besides, the effect of meniscus repair on rotatory laxity should be considered when the indication of anterolateral augmentation is determined.

Persistent synovial inflammation plays important roles in persistent pain development in the rat knee before cartilage degradation reaches the subchondral bone.

BACKGROUND: The major complaint of knee osteoarthritis (OA) is persistent pain. Unlike acute inflammatory pain, persistent pain is usually difficult to manage since its pathology is not fully understood. To elucidate the underlying mechanisms of persistent pain, we established 2 different inflammation-induced arthritis models by injecting monoiodo-acetic acid (MIA) into the joint cavity and performed integrated analyses of the structural changes in the synovial tissue and articular cartilage, sensory neuron rearrangement, and pain avoidance behavior in a rat arthritis model. METHODS: Male Wistar rats received intra-articular injections of MIA (0.2 mg/30 µL, low-dose group; 1 mg/30 µL, high-dose group) in the right knee and phosphate buffered saline (PBS; 30 µL, control group) in the left knee. Fluorogold (FG), a retrograde neural tracer, was used to label the nerve fibers for the identification of sensory neurons that dominate the joints in the dorsal root ganglion (DRG). Both knees were subjected to the intra-articular injection of 2% FG in PBS (5 µL) under anesthesia 5-7 days prior to sacrifice. We performed pain avoidance behavior tests (incapacitance and von Frey tests) at 0, 1, 3, 5, 7, 14, 21, and 28 days. At 5, 14, and 28 days, the rats were sacrificed and the knee joint and DRG were excised for histological assessment. The knee joints were stained with hematoxylin and eosin, safranin O, and calcitonin gene-related peptide (CGRP). The DRG were immunostained with CGRP. RESULTS: A transient inflammatory response followed by mild articular cartilage degeneration was observed in the low-dose MIA model versus persistent inflammation with structural changes in the synovial tissue (fibrosis) in the high-dose model. In the high-dose model, full-thickness cartilage degeneration was observed within 2 weeks post-MIA injection. The pain avoidance behavior tests indicated that persistent synovial inflammation and structural changes of the infrapatellar fat pad may play important roles in persistent knee joint pain before the articular cartilage degeneration reaches the subchondral bone. CONCLUSIONS: Transient inflammation without structural changes of the synovial tissues did not induce persistent pain in the rat knee joint before degradation of the articular cartilage reached the subchondral bone plate.

Risk factors for residual pivot shift after anterior cruciate ligament reconstruction: data from the MAKS group.

PURPOSE: To investigate the risk factors for residual pivot shift test after anterior cruciate ligament (ACL) reconstruction based on a multicenter prospective cohort study. METHODS: This study included patients who were registered in the Multicenter Arthroscopic Knee Surgery Study, a prospective longitudinal multicenter cohort study, and who underwent primary ACL reconstruction using autologous hamstring tendon graft between 2013 and 2016. The exclusion criteria included prior injuries or surgeries in the contralateral knee, prior ligamentous injuries in the involved knee, grade 2 or 3 concomitant ligament injuries, and inflammatory or other forms of osteoarthritis. Data from the preoperative period and at 1-year follow-up were used for further analysis, and patients with incomplete data, re-injury and loss to follow-up were also excluded. Logistic regression analysis was conducted with age, gender, Lachman test, pivot shift test, KT measurement, hyperextension, single-bundle vs. double-bundle, meniscus injury sites, and meniscus treatments as the independent variables, and postoperative pivot shift test was used as the dependent variable. RESULTS: Three hundred and sixty-eight patients were included in the study. Hyperextension knee (P = 0.025) and a preoperative pivot shift test under anesthesia (P = 0.040) were identified as risk factors for a postoperative pivot shift via logistic regression analysis. There were no statistically significant differences in the other variables. CONCLUSIONS: The results from a multicenter cohort study indicated that knee hyperextension and greater preoperative pivot shift under anesthesia were risk factors for residual pivot shift at 1 year after ACL reconstruction. In cases with a preoperative high-grade pivot shift and knee hyperextension, additional anterolateral structure augmentation might be considered in order to eliminate pivot shift and eventually obtain better outcomes after ACL reconstruction. LEVEL OF EVIDENCE: II.

Severe kyphotic deformity resulting from collapses of cemented and adjacent vertebrae following percutaneous vertebroplasty using calcium phosphate cement. A case report.

Percutaneous vertebroplasty (PVP) has been increasingly performed for the treatment of osteoporotic vertebral compression fracture. Despite its minimally invasive procedure, several complications associated with PVP have been reported, including adjacent-level vertebral fracture. Although rare, recollapse of the same vertebrae after PVP has also been reported. However, previous studies have not described a case in which collapses of both the cemented vertebrae and adjacent-level vertebrae occurred following PVP. Here, we report a rare case of severe kyphotic deformity resulting from collapses at the cemented and adjacent vertebrae after PVP using calcium phosphate cement (CPC). The patient required a highly invasive reconstruction procedure as a salvage surgery.

Development of disaster pamphlets based on health needs of patients with chronic illnesses.

The aim of this research was to develop a pamphlet that would enable patients with diabetes, rheumatic diseases, chronic respiratory disease, and dialysis treatment to be aware of changes in their physical conditions at an early stage of a disaster, cope with these changes, maintain self-care measures, and recover their health. Illness-specific pamphlets were produced based on disaster-related literature, news articles, surveys of victims of the Great Hanshin-Awaji Earthquake Disaster and Typhoon Tokage, and other sources. Each pamphlet consisted of seven sections-each section includes items common to all illnesses as well as items specific to each illness. The first section, "Physical Self-Care", contains a checklist of 18 common physical symptoms as well as symptoms specific to each illness, and goes on to explain what the symptoms may indicate and what should be done about them. The main aim of the "Changes in Mental Health Conditions" section is to detect posttraumatic stress disorder (PTSD) at an early stage. The section "Preventing the Deterioration of Chronic Illnesses" is designed to prevent the worsening of each illness through the provision of information on cold prevention, adjustment to the living environment, and ways of coping with stress. In the sections, "Medication Control" and "Importance of Having Medical Examinations", spaces are provided to list medications currently being used and details of the hospital address, in order to ensure the continued use of medications. The section, "Preparing for Evacuations" gives a list of everyday items and medical items needed to be prepared for a disaster. Finally, the "Methods of Contact in an Emergency" section provides details of how to use the voicemail service. The following content-specific to each illness also was explained in detail: (1) for diabetes, complications arising from the deterioration of the illness, attention to nutrition, and insulin management; (2) for rheumatic diseases, a checklist of factors indicating the worsening of the illness and methods of coping with stress; (3) for chronic respiratory disease, prevention of respiratory infections and management of supplemental oxygen; and (4) for patients requiring dialysis, conditions of dialysis (such as dry weight, dialyzer, number of dialysis treatments, and dialysis hours) and what to do if a disaster occurs during dialysis. It is expected that these pamphlets will be useful to patients with chronic illnesses, and will be used to prepare for disasters, thereby helping the patients cope with the unusual situation that during a disaster and recover as soon as possible.