Effect of bone marrow aspiration concentrate and platelet-rich plasma combination in anterior cruciate ligament reconstruction: a randomized, prospective, double-blinded study.

BACKGROUND: The effect of bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP) combination in enhancing graft maturation and tendon-bone tunnel interfacial healing after anterior cruciate ligament (ACL) reconstruction remains unclear. We hypothesised that BMAC and PRP combination could lead to better clinical results and better graft maturation/interface healing than PRP alone or conventional ACL reconstruction without any other biologic augmentation. METHODS: In this randomised double-blind prospective study, patients undergoing ACL reconstruction surgery were randomly assigned into three groups: (1) control group (without any biologic augmentation), (2) PRP treatment group, and (3) combined BMAC and PRP (BMAC + PRP) group. Moreover, they were evaluated using the clinical functional score, laxity examination, and magnetic resonance imaging (MRI) analysis. RESULTS: No significant difference was observed in the improvement of functional scores among groups. However, laxity improvement at 24 weeks showed a significant difference with the BMAC + PRP group having the lowest laxity. MRI analysis showed no significant change in whole graft maturation among groups. In particular, the BMAC + PRP group showed delayed signal peak and higher graft signal at 24 weeks compared with the other two groups; however, the difference was not significant. With regard to tendon-bone interfacial healing, the BMAC + PRP group showed significantly wider tendon-bone interface in the femoral bone tunnel at 24 weeks compared with the other two groups. Moreover, the BMAC + PRP group showed significantly higher peri-tunnel edema signal in the femoral bone tunnel at 12 weeks compared with the other two groups. CONCLUSION: PRP alone and BMAC and PRP combination showed limited enhancing effect in clinical function, graft maturation and tendon-bone interfacial healing compared with control (no additional treatment). When BMAC is used in ACL reconstruction, the possibility of greater inflammation in the early stage to graft maturation and bone tunnel healing should be considered.

Global Impact of the COVID-19 Pandemic on Orthopedics and the Implications of Telemedicine: A Systematic Review of the Literature.

This study aimed to systematically review the literature on the impact of the coronavirus disease (COVID-19) pandemic on the orthopedics field by focusing on multiple aspects, including orthopedic training and application, performance, work loading, change of practice, research work, and other psychological factors. Published articles were searched using the PubMed database. Articles were selected in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of 58 studies published between 1 January 2020 and 1 October 2021, 57 peer-reviewed original articles were included. Nearly 90% of students experienced an impact of the pandemic on application. The impact on training stemmed from redeployment rates of 20.9-23.1%. The rate of emergency or outpatient visits decreased from 18% to 58.6%. The rates of all surgeries or emergency surgeries decreased by 15.6-49.4%, while the rates of elective surgeries decreased by 43.5-100%. The rate of work loading ranged from 33% to 66%. Approximately 50-100% of surgeons had a change of practice. A total of 40.5% of orthopedic surgeons experienced mild psychological pressure. Approximately 64% had stopped research participant recruitment. Most of the included studies were conducted in Europe, followed by Asia and North America. It is suggested orthopedic surgeons prepare more sufficient, flexible, and reservable staffing measures, proper preventive strategies and surgical scheduling algorithms, and set up dedicated venues and equipment for routine telemedicine with staff training for virtual teaching or consultations in case of future impacts on orthopedics.

Does coracoclavicular augmentation additional to hook plate fixation provide benefits in acute unstable acromioclavicular dislocation? A meta-analysis.

BACKGROUND: Acromioclavicular joint (ACJ) dislocation is a common shoulder injury. In treating acute unstable ACJ dislocation, a hook plate (HP) is a straightforward and popular option for ensuring proper reduction and rigid fixation while promoting AC and coracoclavicular (CC) ligament healing. Surgeons typically remove the HP to prevent subacromial impingement and acromial osteolysis; however, concerns about redislocation after implant removal remain. Therefore, additional CC augmentation may be helpful in combination with HP fixation. The aim of this meta-analysis is to compare the outcomes and complications of HP fixation with or without additional CC augmentation for acute unstable ACJ dislocation. METHODS: We searched the PubMed, EMBASE, and Web of Science databases for relevant case-control studies. The primary outcomes were patient-reported outcome measures; the secondary outcomes were pain measured using a visual analog scale (VAS), CC distance (CCD), and complications. Continuous data were assessed using weighted standardized mean differences (SMDs) with 95% confidence intervals (CIs), and dichotomous data were evaluated with Mantel-Haenszel odds ratio (ORs) with 95% CIs. RESULTS: We analyzed one randomized control trial and four case-control studies comparing HP fixation with or without CC augmentation. A total of 474 patients with Rockwood type III or V ACJ dislocation were included. We found no differences in Constant-Murley score (SMD, - 0.58, 95% CI - 1.41 to 0.26; P = 0.18), American Shoulder and Elbow Surgeons score (SMD, 0.21, 95% CI - 0.10 to 0.52; P = 0.19), University of California at Los Angeles shoulder rating scale score (SMD, - 0.02, 95% CI - 1.27 to 1.23; P = 0.97), or VAS pain score (SMD, 0.36, 95% CI - 0.16 to 0.88; P = 0.17) between groups. The CC augmentation group had lower odds of osteolysis (OR, 0.27, 95% CI 0.10 to 0.74; P = 0.01) and a shorter CCD (SMD, - 0.29, 95% CI - 0.57 to - 0.01; P = 0.04). CONCLUSION: HP fixation with CC augmentation is preferable for acute unstable ACJ dislocations. Although CC augmentation did not provide additional benefits related to functional outcomes or pain, it resulted in greater reduction maintenance after implant removal and a 73% lower risk of acromial osteolysis. TRIAL REGISTRATION: PROSPERO ( CRD42021271118 ).

Analyze the Differential Rates of Anterior Cruciate Ligament Injuries Between Men and Women by Biomechanical Study of Single-Leg Landing in Badminton.

BACKGROUND: In female badminton players, certain landings are associated with injury to the anterior cruciate ligament (ACL). However, the kinematic and kinetic changes of the landing leg and the effects of risky posture on ACL injuries among female vs male badminton players are still unknown. We hypothesized that female players land with a significantly higher knee valgus angle and moment compared to male players during single-leg landings in badminton. METHODS: Ten male and ten female badminton players were enrolled in this study. In the laboratory, these subjects performed back-stepping to the backhand side with a concurrent overhead stroke, a single-leg landing on the force plate, and a return to the starting position. The kinematic data in the stance phase were normalized ranging from 0% as initial contact to 100% as toe-off; and 0% as initial contact to 100% as maximum knee flexion in the impact phase. RESULTS: The knee valgus angle in female players was significantly higher in initial contact (5.06° ± 6.83° vs - 5.10° ± 4.30, p = .001) and maximal knee valgus angle (7.58° ± 9.54° vs - 3.93° ± 4.22°, p = .004) compared to male players. The knee valgus moment was significantly higher in male players than female players ( - 0.09 ± 0.12 vs 0.03 ± 0.10 N∙m/kg, p = .032) in initial contact during the impact phase. During landings, female badminton players had lower hip flexion angles, greater knee valgus angles, and greater ankle dorsiflexion angles. CONCLUSION: Female badminton players presented higher knee valgus angles but smaller knee valgus moments compared with male players during backward single-leg landings. The concomitant kinematic and kinetic changes of the hip, knee, and ankle joints also can play an important role in the higher incidence of ACL injury in female athletes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s43465-021-00421-6.

Effect of Freshly Isolated Bone Marrow Mononuclear Cells and Cultured Bone Marrow Stromal Cells in Graft Cell Repopulation and Tendon-Bone Healing after Allograft Anterior Cruciate Ligament Reconstruction.

Graft cell repopulation and tendon-bone tunnel healing are important after allograft anterior cruciate ligament reconstruction (ACLR). Freshly isolated bone marrow mononuclear cells (BMMNCs) have the advantage of short isolation time during surgery and may enhance tissue regeneration. Thus, we hypothesized that the effect of intra-articular BMMNCs in post-allograft ACLR treatment is comparable to that of cultured bone marrow stromal cells (BMSCs). A rabbit model of hamstring allograft ACLR was used in this study. Animals were randomly assigned to the BMMNC, BMSC, and control groups. Fresh BMMNCs isolated from the iliac crest during surgery and cultured BMSCs at passage four were used in this study. A total of 1 × 107 BMMNCs or BMSCs in 100 µL phosphate-buffered saline were injected into the knee joint immediately after ACLR. The control group was not injected with cells. At two and six weeks post operation, we assessed graft cell repopulation with histological and cell tracking staining (PKH26), and tendon-bone healing with histological micro-computed tomography and immunohistochemical analyses for collagen I and monocyte chemoattractant protein-1 (MCP1). At two weeks post operation, there was no significant difference in the total cell population within the allograft among the three groups. However, the control group showed significantly higher cell population within the allograft than that of BM cell groups at six weeks. Histological examination of proximal tibia revealed that the intra-articular delivered cells infiltrated into the tendon-bone interface. Compared to the control group, the BM cell groups showed broader gaps with interfacial fibrocartilage healing, similar collagen I level, and higher MCP1 expression in the early stage. Micro-CT did not reveal any significant difference among the three groups. BMMNCs and BMSCs had comparable effects on cell repopulation and interfacial allograft-bone healing. Intra-articular BM cells delivery had limited benefits on graft cell repopulation and caused higher inflammation than that in the control group in the early stage, with fibrocartilage formation in the tendon-bone interface after allograft ACLR.

Beneficial Therapeutic Approach of Acellular PLGA Implants Coupled With Rehabilitation Exercise for Osteochondral Repair: A Proof of Concept Study in a Minipig Model.

BACKGROUND: Osteochondral (OC) repair presents a significant challenge to clinicians. However, whether the use of acellular spongy poly(lactic-co-glycolic acid) (PLGA) scaffolding plus treadmill exercise as a rehabilitation program regenerates OC defects in a large-animal model has yet to be determined. HYPOTHESIS: PLGA scaffolding plus treadmill exercise may offer improved OC repair for both high and low weightbearing regions in a minipig model. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 9 mature minipigs (18 knees) were randomly divided into the treadmill exercise (TRE) group or sedentary (SED) group. All pigs received critically sized OC defects in a higher weightbearing region of the medial condyle and a lower weightbearing region of the trochlear groove. In each minipig, a PLGA scaffold was placed in the defect of the right knee (PLGA subgroup), and the defect of the left knee was untreated (empty defect [ED] subgroup). The TRE group performed exercises in 3 phases: warm-up, 3 km/h for 5 minutes; main exercise, 4 km/h for 20 minutes; and cool-down, 3 km/h for 5 minutes. The total duration was about 30 minutes whenever possible. The SED group was allowed free cage activity. RESULTS: At 6 months, the TRE-PLGA group showed the highest gross morphology scores and regenerated a smooth articular surface covered with new hyaline-like tissue, while the defects of the other groups remained and contained nontransparent tissue. Histologically, the TRE-PLGA group also revealed sound OC integration, chondrocyte-like cells embedded in lacunae, abundant glycosaminoglycans, a sound collagen structure, and modest inflammatory cells with an inflammatory response (ie, tumor necrosis factor-α, interleukin-6). In addition, in the medial condyle region, the TRE-PLGA group (31.80 ± 3.03) had the highest total histological scores (TRE-ED: 20.20 ± 5.76; SED-PLGA: 10.25 ± 6.24; SED-ED: 11.75 ± 6.50; P = .004). In the trochlear groove region, the TRE-PLGA group (30.20 ± 6.42) displayed significantly higher total histological scores (TRE-ED: 19.60 ± 7.00; SED-PLGA: 10.00 ± 5.42; SED-ED: 11.25 ± 5.25; P = .006). In contrast, the SED-PLGA and SED-ED groups revealed an irregular surface with abrasion, fibrotic tissue with an empty void and inflammatory cells, disorganized collagen fibers, and less glycosaminoglycan deposition. Micro-computed tomography analysis revealed that the TRE-PLGA group had integrated OC interfaces with continued remodeling in the subchondral bone. Furthermore, comparing the 2 defect regions, no statistically significant differences in cartilage regeneration were detected, indicating the suitability of this regenerative approach for both high and low weightbearing regions. CONCLUSION: Implanting an acellular PLGA scaffold plus treadmill exercise promoted articular cartilage regeneration for both high and low weightbearing regions in minipigs. CLINICAL RELEVANCE: This study suggests the use of a cell-free porous PLGA scaffold and treadmill exercise rehabilitation as an alternative therapeutic strategy for OC repair in a large-animal knee joint model. This combined effect may pave the way for biomaterials and exercise regimens in the application of OC repair.

Extracorporeal shock wave promotes activation of anterior cruciate ligament remnant cells and their paracrine regulation of bone marrow stromal cells' proliferation, migration, collagen synthesis, and differentiation.

AIMS: Proliferation, migration, and differentiation of anterior cruciate ligament (ACL) remnant and surrounding cells are fundamental processes for ACL reconstruction; however, the interaction between ACL remnant and surrounding cells is unclear. We hypothesized that ACL remnant cells preserve the capability to regulate the surrounding cells' activity, collagen gene expression, and tenogenic differentiation. Moreover, extracorporeal shock wave (ESW) would not only promote activity of ACL remnant cells, but also enhance their paracrine regulation of surrounding cells. METHODS: Cell viability, proliferation, migration, and expression levels of Collagen-I (COL-I) A1, transforming growth factor beta (TGF-ß), and vascular endothelial growth factor (VEGF) were compared between ACL remnant cells untreated and treated with ESW (0.15 mJ/mm2, 1,000 impulses, 4 Hz). To evaluate the subsequent effects on the surrounding cells, bone marrow stromal cells (BMSCs)' viability, proliferation, migration, and levels of Type I Collagen, Type III Collagen, and tenogenic gene (Scx, TNC) expression were investigated using coculture system. RESULTS: ESW-treated ACL remnant cells presented higher cell viability, proliferation, migration, and increased expression of COL-I A1, TGF-ß, and VEGF. BMSC proliferation and migration rate significantly increased after coculture with ACL remnant cells with and without ESW stimulation compared to the BMSCs alone group. Furthermore, ESW significantly enhanced ACL remnant cells' capability to upregulate the collagen gene expression and tenogenic differentiation of BMSCs, without affecting cell viability, TGF-ß, and VEGF expression. CONCLUSION: ACL remnant cells modulated activity and differentiation of surrounding cells. The results indicated that ESW enhanced ACL remnant cells viability, proliferation, migration, and expression of collagen, TGF-ß, VEGF, and paracrine regulation of BMSC proliferation, migration, collagen expression, and tenogenesis.Cite this article: Bone Joint Res 2020;9(8):458-468.

Medication-Taking Habit and Outcome of Glucosamine Sulfate for Osteoarthritis Patients Influenced by National Health Insurance Regulations in Taiwan.

This study compared the dosage and different medication-taking habits of glucosamine sulfate (GS) for osteoarthritis patients and evaluated the influence of the National Health Insurance (NHI) prescription guidelines. The subjects were collected from the Taiwan NHI Research Database from 1 January 2004, to 31 December 2008, and 10,501 osteoarthritis patients were included. Then, 271 patients who continuously used nonsteroidal anti-inflammatory drug (NSAIDs) and started to receive glucosamine for the first time since 2005 (no glucosamine use in 2004) were compared with 593 age-matched patients who continuously used NSAIDs but never received any glucosamine drugs from 2004 to 2008. The mean treatment duration of the glucosamine-treated and NSAID-treated groups was 40.38 ± 7.89 and 45.82 ± 3.89 months, respectively. The most common medication-taking habit was 250 mg 3 times a day for 3 months and discontinued for 3 months. It was as indicated and covered by the NHI. Only 0.7% of patients used the recommended daily dosage of 1500 mg. Patients using GS surprisingly had a higher incidence rate of joint replacement surgery than those who did not use GS. The NHI prescription guidelines may cause patient selection bias, which decreases the efficacy of GS. Moreover, patients tend to have an altered medication-taking habit, with a daily dosage of 750 mg, which is lower than the recommended therapeutic dose.

The Elbow Technique: A Novel Reduction Technique for Anterior Shoulder Dislocations.

BACKGROUND: Anterior dislocation of the glenohumeral joint is a common upper extremity injury in orthopedic and emergency medicine. The aim of this study was to introduce a novel reduction technique, "elbow technique," for anterior shoulder dislocations. DISCUSSION: This study included 26 patients with anterior shoulder dislocation who were treated using the elbow technique in our hospital's emergency department between October 2014 and December 2015. One orthopedic physician performed the reduction maneuver and the vast majority of the patients were sedated. Patients who presented with posterior shoulder dislocation, remained dislocated for more than 7 days, who had Neer three or four parts proximal humerus fractures, and who had received previous shoulder surgery were excluded from this study. Twenty-one dislocations (80% of the patients) were primary. Six patients (23% of the dislocations) had associated fractures of the greater tuberosity. All of the patients were successfully reduced with the elbow technique. Mean time for reduction was 5 s (range 3-69 s). No iatrogenic fractures or neurovascular injuries were noted after the reductions. CONCLUSIONS: The elbow technique involves traction, leverage, pulsion, and can be performed by a single operator. The elbow technique is a safe, elegant, simple, effective, fast, and gentle reduction procedure for anterior shoulder dislocations in the emergency department.

Therapeutic Effects of the Addition of Platelet-Rich Plasma to Bioimplants and Early Rehabilitation Exercise on Articular Cartilage Repair.

BACKGROUND: Treating articular cartilage lesions is clinically challenging. However, whether the addition of autologous platelet-rich plasma (PRP) to bioimplants along with early rehabilitation exercise provides therapeutic effects and regenerates the osteochondral defect remains uninvestigated. HYPOTHESIS: The addition of PRP to a polylactic-co-glycolic acid (PLGA) scaffold along with continuous passive motion (CPM) in osteochondral defects may offer beneficial in situ microenvironment changes to facilitate hyaline cartilage and subchondral bone tissue repair. STUDY DESIGN: Controlled laboratory study. METHODS: In 26 rabbits, 52 critical osteochondral defects were created in bilateral femoral trochlear grooves. The rabbits were allocated to 1 of the following 3 groups: PRP gel (PG group), PRP + PLGA scaffold (PP group), and PRP + PLGA scaffold + CPM (PPC group). At 4 and 12 weeks after surgery, the specimens were assessed by a macroscopic examination, a histological evaluation with immunohistochemical staining, and micro-computed tomography. RESULTS: The PPC group exhibited the most favorable therapeutic outcomes in terms of hyaline cartilage regeneration. At week 4, the PPC group exhibited significantly higher levels of glycosaminoglycan (GAG) and collagen (COL) II and modest increases in COL I, matrix metalloproteinase-3 (MMP-3), and inflammatory cells with tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). At week 12, the PPC group had significantly higher tissue repair scores, corresponding to a sound articular cartilage surface and chondrocyte and collagen arrangement. This group demonstrated restored hyaline cartilage and mineralized bone volume per tissue volume, which had an integrating structure in the repair site. However, the PG and PP groups exhibited mainly fibrous tissue and fibrocartilage, corresponding to higher expressions of COL I, TNF-α, IL-6, and MMP-3. CONCLUSION: PRP with a PLGA graft along with early CPM exercise is promising for the repair of osteochondral defects in rabbit knee joints. CLINICAL RELEVANCE: This study demonstrates the efficacy of a triad therapy involving the addition of PRP to bioimplants along with early CPM intervention for hyaline cartilage and subchondral regeneration. However, PRP alone (with or without PLGA implants) is limited to osteochondral defect repair without significant regeneration.

Functional movement screen comparison between the preparative period and competitive period in high school baseball players.

BACKGROUND/OBJECTIVE: Although the functional movement screen (FMS) has been widely applied for screening athletes, no previous study has used FMS scores to examine the association between distinct training seasons in high school baseball players. The aims of this study were to ascertain the functional movement screen (FMS) scores differences between the preparative period (PPP) and the competitive period (CPP) among high school baseball players and further determine whether FMS can be used as a tool to predict injuries during two major periods. METHODS: Fifty-five male high school baseball players (age 15.3 ±â€¯1.7 years; height 1.7 ±â€¯0.8 m; weight 64.6 ±â€¯11.5 kg) volunteered. Athletic injuries were reported through a self-report questionnaire. Players performed the FMS during the PPP and the CPP. A receiver operator characteristic (ROC) curve to calculate a cutoff total composite score ≤ 14 for the relationship between the FMS score and injury. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and an area under the curve (AUC) were calculated. RESULTS: FMS individual task score and total composite score were significantly lower in the CPP than in the PPP. However, a cutoff total composite score ≤14 for risk of injury, determined through a ROC curve, represented a low sensitivity of 58%, NPV of 66%, an AUC of 69%, specificity of 79%, and PPV of 71%. CONCLUSION: Although the low sensitivity and NPV and AUC scores indicated that the FMS does not accurately predict the risk of injury, the FMS individual task and total composite scores differed significantly between the PPP and CPP. Therefore, FMS could be used as a tool to identify physical deficiencies between distinct training seasons; however, utilizing the FMS as a screening tool for injury prediction in particular during the CPP in this population would not be recommended.

A Preclinical Assessment of Early Continuous Passive Motion and Treadmill Therapeutic Exercises for Generating Chondroprotective Effects After Anterior Cruciate Ligament Rupture.

BACKGROUND: Anterior cruciate ligament (ACL) injury is a well-known risk factor for the development of posttraumatic osteoarthritis (PTOA). However, whether using continuous passive motion (CPM) with or without additional treadmill exercise (TRE) in early ACL injury might provide chondroprotective effects and further decrease the risk of PTOA has yet to be determined. HYPOTHESIS: CPM may offer an enhanced chondroprotective effect, but TRE may attenuate that effect due to the mechanical stress on the joint and inflammatory cytokines in the joint. STUDY DESIGN: Controlled laboratory study. METHODS: Thirty adult New Zealand White male rabbits were randomly allocated to sedentary (SED), CPM, TRE, or CPM+TRE groups. Each rabbit underwent an ACL transection (ACLT) on the right knee, with the contralateral knee used as an internal control (sham). The 4 joint surfaces (ie, medial and lateral femoral condyles and tibial plateaus) were evaluated 4 weeks after surgery for gross appearance, histological characteristics, and quantitative osteoarthritis (OA) scores. RESULTS: Overall, at the end of testing, the CPM group experienced the best protective therapeutic effects in all compartments. In gross appearance, CPM resulted in normal articular surfaces, while the TRE and SED groups exhibited surface abrasion. Histological analysis showed significant differences in articular cartilage status. The CPM group had significantly better histological OA scores ( P < .01), corresponding to the smoothest cartilage surface and sound chondrocyte and collagen arrangement. This group also showed abundant glycosaminoglycan (GAG) content and a sound growth microenvironment, with significantly lower expression levels of the inflammatory cytokine tumor necrosis factor α and the apoptotic marker caspase 3. In contrast, the TRE and SED groups showed several features of damage: distinct graded cartilage abrasion; damaged collagen fibers, corresponding to noticeable collagen type X (osteoarthritic cartilage); reduced cartilage thickness; fewer cartilaginous cells; and the appearance of chondrocyte clusters. These groups also showed loss of GAG, corresponding to higher levels of inflammatory cytokines and apoptosis of articular chondrocytes. Furthermore, the CPM+TRE group displayed visible pathological changes in the superficial cartilage, indicating that early loading exercise may contribute to osteoarthritis. The sham treatment showed no difference in the changes in all compartments between groups. CONCLUSION: Immediate CPM therapy produces a superior in situ microenvironment for reducing the occurrence of PTOA after ACL injury without reconstruction in rabbits. CLINICAL RELEVANCE: These data suggest that immediate application of CPM therapy may be necessary to create a sound microenvironment in joints and possibly to decrease the risk of PTOA without or while awaiting ACL reconstruction. In contrast, both early active loading exercise and inactivity lead to the development of PTOA.

Can Early Rehabilitation Prevent Posttraumatic Osteoarthritis in the Patellofemoral Joint after Anterior Cruciate Ligament Rupture? Understanding the Pathological Features.

Knee instability resulting from anterior cruciate ligament (ACL) rupture is a high-risk factor for posttraumatic osteoarthritis (PTOA) in the patellofemoral joint (PFJ). However, whether non-weight-bearing and weight-bearing treatments have chondroprotective effects remains unclear. Twenty-four adult New Zealand White male rabbits were employed in this study. All animals received ACL transection in the right knee and sham surgery in the left knee. The rabbits were randomly assigned to the following groups: (I) In the sedentary (SED) group, the rabbits (n = 6) were simply kept in their cage; (II) In the continuous passive motion (CPM) group, the rabbits (n = 6) performed CPM exercise for 7 days, starting from the first postoperative day; (III) In the active treadmill exercise (TRE) group, the rabbits (n = 6) performed TRE for 2 weeks; (IV) In the CPM + TRE group, the rabbits (n = 6) executed CPM exercise, followed by TRE. Two joint surfaces (the retropatella and femoral trochlear groove) were assessed at 4 weeks after operation. Although the gross appearance in each group was comparable, histological examination revealed significant differences in the articular cartilage status. The CPM group exhibited a greater thickness of articular cartilage, maintenance of tidemark continuity, abundant glycosaminoglycan (GAG), and significantly lower inflammatory cytokine 9, e.g., tumor necrosis factor-alpha (TNF-α) 0 levels, with modest cell apoptosis (i.e., caspase-3). By contrast, the TRE group displayed the worst pathological features: an irregular cartilage surface and chondrocyte disorganization, reduced cartilage thickness, breakdown of the tidemark, depletion of collagen fibers, loss of GAG, and the highest levels of TNF-α and caspase-3 expression. Furthermore, the CPM + TRE group had more favorable outcomes than the SED group, indicating that suitable exercise is needed. The sham treatment displayed no variance in the changes in the two joint surfaces among groups. These data indicate that the application of early CPM rehabilitation is suggested for subjects in order to decrease the risk of PTOA without ACL reconstruction in the PFJ compartment in rabbits. The early TRE program, however, had harmful outcomes. Additionally, inactivity was discovered to initiate the development of PTOA.

Changes of muscle mechanics associated with anterior cruciate ligament deficiency and reconstruction.

Isometric and isokinetic knee strength deficits were examined on patients with anterior cruciate ligament (ACL) injury before and after ACL reconstruction. Muscle strengths of the uninjured and injured knees were measured from an ACL injured (n = 12) and a control (n = 15) group. Five isometric (10, 30, 50, 70, and 90° of knee flexion) and 5 isokinetic (50, 100, 150, 200, and 250°·s) strengths of quadriceps and hamstrings were measured prereconstruction and postreconstruction (3 and 6 months). Compared with the controls, the uninjured knee showed normal strength and patterns of length-tension and force-velocity relationships. Compared with the uninjured knee, the injured knees showed a generally 25-30% decrease in quadriceps and hamstrings strength with normal patterns of length-tension and force-velocity relationships. By 3 months of reconstruction, weakness of quadriceps of the injured knees was exacerbated, particularly at lengthened positions (∼ 40% of the uninjured knees at knee flexion 70 and 90°) and at slower velocities (∼35% of the uninjured knees at the 50 and 100°·s, p < 0.05), with flattened patterns of mechanical output. By 6 months of reconstruction, the quadriceps of the injured knees still showed significant weakness (∼50% of the uninjured knees) in both contraction types (isometric at knee flexion 90° and isokinetic at 50°·s, p < 0.05). The hamstrings of the injured knees had not shown significant changes after reconstruction. A strengthening program placing emphasis on greater knee flexion angles and slower movement speed with sufficient training duration post ACL reconstruction is recommended because of long-lasting and exacerbated weakness during 3 and 6 months postreconstruction.

MR grading system of osteochondritis dissecans lesions: comparison with arthroscopy.

OBJECTIVE: To assess the diagnostic performance of combined three-dimensional (3D) gradient-echo (GRE) T1-weighted and routine MR imaging protocol for the evaluation of osteochondritis dissecans (OCD). MATERIALS AND METHODS: This prospective study was approved by our institutional review board and all patients gave informed consent. Three-dimensional GRE MR sequence was added to the routine protocol performed on 40 consecutive patients (35 men, 5 women; age range, 12-57 years; mean age, 20 years) with 17 juvenile and 24 adult OCD lesions (27 in knees; 14 in elbows) which were confirmed by arthroscopy. Two independent musculoskeletal radiologists reviewed all MR images. The OCD lesions were classified into five stages by assessing the signal intensity of fragment-bone interface and the integrity of articular cartilage on MR images. Stage-IV and -V lesions were considered as unstable. The sensitivity, specificity, accuracy, and interobserver agreement (κ statistics) were calculated. RESULTS: The sensitivity, specificity, and accuracy for detection of OCD instability were 100% (11 of 11), 100% (6 of 6), and 100% (17 of 17) in juvenile lesions; and 93% (14 of 15), 100% (9 of 9), and 96% (23 of 24) in adult lesions. The overall accuracy of MR findings in determining the staging was 90% (37 of 41) for reader 1 and 83% (34 of 41) for reader 2. Agreement between readers was substantial with a κ value of 0.75 for MR staging of OCD lesions. CONCLUSIONS: Three-dimensional GRE T1-weighted MR imaging combined with the routine sequences demonstrates excellent diagnostic capabilities in detecting unstable OCD lesions.

Effect of various forearm axially rotated postures on elbow load and elbow flexion angle in one-armed arrest of a forward fall.

BACKGROUND: Falling onto the outstretched hand is a major cause of upper extremity injury. The overall objectives of this study were to develop an experimental model for elbow load during a simulated fall onto one-armed arrest using three different forearm axially rotated postures as alternative fall arrest strategies. Additionally, the relationship between the elbow flexion angle and different axially rotated postures were also investigated. METHODS: Fifteen healthy young male Taiwanese graduate students with an average age of 23 years were studied. Subjects performed a one-armed arrest of a 5 cm fall onto a force plate. Each subject fell onto the force plate with his forearm 45 degrees axial externally rotated (ER), non-rotated (NR), and 45 degrees axial internally rotated (IR) postures. Kinematics and kinetics of the upper extremity were calculated and analyzed by using laboratory-developed motion analysis procedures. FINDINGS: The valgus-varus shear forces in the ER group were 1.4 times greater than the NR group, and 2.7 times greater than the IR group. The elbow joint remained at almost full extension in the ER (3.9 degrees) group, while elbow flexion angle was observed in the NR (24.6 degrees) and IR (40.3 degrees) groups. INTERPRETATION: A fall onto the outstretched hand with an externally rotated forearm should be avoided in order to reduce excessive valgus-varus shear force on the elbow joint. Knowledge of elbow kinematics and kinetics during a forward fall with various forearm axially rotated posture may be helpful in preventing injuries.