Long noncoding RNA UCA1 promotes the chondrogenic differentiation of human bone marrow mesenchymal stem cells via regulating PARP1 ubiquitination.

Bone marrow mesenchymal stem cells (BMSCs) possess the potential to differentiate into cartilage cells. Long noncoding RNA (lncRNAs) UCA1 has been confirmed to improve the chondrogenic differentiation of marrow mesenchymal stem cells (MSCs). Herein, we further investigated the effects and underlying mechanisms in these processes. the expression of UCA1 was positively associated with chondrogenic differentiation and the knockdown of UCA1 has been shown to attenuate the expression of chondrogenic markers. RNA pull down assay and RNA immunoprecipitation showed that UCA1 could directly bind to PARP1 protein. UCA1 could improve PARP1 protein via facilitating USP9X-mediated PARP1 deubiquitination. Then these processes stimulated the NF-κB signaling pathway. In addition, PARP1 was declined in UCA1 knockdown cells, and silencing of PARP1 could diminishes the increasing effects of UCA1 on the chondrogenic differentiation from MSCs and signaling pathway activation. Collectively, these outcomes suggest that UCA1 could act as a mediator of PARP1 protein ubiquitination and develop the chondrogenic differentiation of MSCs.

The effects of lateral meniscus posterior root tears or repair with anterior cruciate ligament reconstruction on the pressure of the patellofemoral joint: A biomechanical evaluation.

Objective: The aim of our study was to evaluate the effect of tear and repair of the lateral meniscal posterior root (LMPR) on the patellofemoral contact pressure of the knee after anterior cruciate ligament (ACL) reconstructed. Methods: This was a descriptive study. Six fresh-frozen cadaveric knees collected by The Third Hospital of Hebei Medical University from January 2019 and January 2022 were placed on a customized testing rig. Patellofemoral contact pressures were measured at 30°, 60°, and 90° of flexion using pressure-sensitive film inserted between the patella and trochlea. The following knee states were tested: ACL reconstruction and intact lateral meniscus, ACL reconstruction, and LMPR tear, and ACL reconstruction and LMPR repair. Pressure measurements were recorded for each state. Result: In the ACL-reconstructed knee, a tear of the LMPR increased patellofemoral contact pressure at 30° of knee flexion. The repair of the posterior root by transosseous pull-out suture reduced the patellofemoral contact pressure as the status of intact lateral meniscal posterior root at 30° of knee flexion. There was no statistical difference between ACL reconstruction with the intact meniscal root and with the meniscal root tear and with the meniscal root repair at 60° and 90° of knee flexion. Conclusion: The posterior root tear and repair of the lateral meniscus could have an influence on patellofemoral contact stress of the knee after ACL reconstruction at 30° of knee flexion.

A simple arthroscopic technique for treatment of displaced "hinged" type of posterior cruciate ligament avulsion fractures.

BACKGROUND: The surgical technique for treatment of tibial avulsion fractures of the posterior cruciate ligament (PCL) remains challenging due to the deep-located lesion and the complexity of the anatomy. The purpose of this study was to report preliminary results of an arthroscopic technique in patients with the "hinged" type PCL tibial avulsion fractures. METHODS: Twenty-eight patients with the displaced "hinged" fractures with elevation of the posterior aspect of the bony fragment were arthroscopically treated. The bony fragment was reducted and fixed with the sutures passing through only one single tibial tunnel. The clinical outcomes were assessed by Lysholm score, Tegner activity score, and the side-to-side differences of KT-1000 measurement. The reduction and union of the fracture were assessed by radiography of the knee. RESULTS: Patients were followed up for a mean of 19 (12 to 24) months. There were no surgery-related complications, and all patients regained normal range of motion of the knees at the last follow-up. The Lysholm score significantly increased from preoperative 14.78 ± 8.23 to postoperative 96.96 ± 3.62 (P = 0.000). The Tegner score was 6.78 ± 1.35 pre-injury and 6.48 ± 1.20 at the last follow-up with no statistical difference (P = 0.688). The KT-1000 side-to-side differences significantly decreased from 8.26(SD 1.86; 6 to 12) pre-operatively to 0.91 (SD 0.85; 0 to 3) (P = 0.000). X-rays showed that satisfactory reduction and solid union was achieved in all patients. CONCLUSION: The arthroscopic suture fixation through single-tibial tunnel technique yielded good clinical and radiographic outcome for treatment of displaced "hinged" type of PCL avulsion fractures.

Association of depressive symptoms and risk of knee pain: the moderating effect of sex.

BACKGROUND: Depression has been shown in some studies to be associated with knee pain. Females were widely recognized as more vulnerable to depression and knee pain than males. However, the role of sex in this correlation was under-researched. This study aimed to investigate the association between depressive symptoms and subsequent knee pain, as well as whether and how sex would moderate this association based on a four-wave (Wave 1 in 2010-2011, Wave 2 in 2013, Wave 3 in 2015, and Wave 4 in 2018) longitudinal study among middle-aged and elderly Chinese adults. METHODS: Seventeen thousand seven hundred eight participants were recruited and followed in the China Health and Retirement Longitudinal Study (CHARLS). Ten thousand four hundred fifty-one entered the final analysis based on the inclusion and exclusion criteria. Knee pain was assessed by self-report. Depressive symptoms were evaluated using the validated 10-item Center for Epidemiological Studies-Depression Scale (CESD-10). Cox proportional hazards models were used to calculate hazard ratios with 95% confidence intervals (CIs) after controlling potential confounders to examine the association between depressive symptoms and subsequent incident and persistent knee pain. Non-linear association of depressive symptoms score (CESD-10) and risk of knee pain was also investigated via applying 3-knotted restricted cubic spline regression. An interaction term of depressive symptoms status and sex was added to investigate the moderating effect of sex on the relationship between depressive symptoms status and the risk of knee pain. RESULTS: The median follow-up time was seven years for all the outcomes. Participants with depressive symptoms were 1.45 times (95% CI: 1.34-1.56) and 2.16 times (95% CI: 1.85-2.52) more likely to develop the incident and persistent knee pain after multivariable were adjusted, compared with those without depressive symptoms. There was a non-linear association between CESD-10 score and risk of knee pain. Compared with females, males had an enhanced correlation between depressive symptoms status and knee pain (multivariable-adjusted HR: 1.22, 95% CI: 1.05-1.42 and HR: 1.57, 95% CI: 1.14-2.17 for the incident and persistent knee pain, respectively). CONCLUSION: Depressive symptoms are independently associated with an excess risk of knee pain, with a stronger correlation for males than females among middle-aged and elderly Chinese adults.

Surgical medial patellofemoral ligament reconstruction versus non-surgical treatment of acute primary patellar dislocation: a prospective controlled trial.

PURPOSE: The acute primary (first-time) lateral patellar dislocation is associated with a high rate of functional disability. There is no consensus as to the choice of surgical or non-surgical treatment for these patients. The aim of this study is to compare the clinical results between the surgical (reconstruction of the medial patellofemoral ligament [MPFL]) and non-surgical treatments for acute primary patellar dislocations. METHODS: Sixty-nine skeletally mature patients (69 knees) were included in this prospective non-randomized controlled trial. At least one predisposing factor for patellar dislocation (including patella alta, high lateral patellar tilt, trochlear dysplasia, and increased TT-TG distance) was identified in the included patients. Thirty patients were treated surgically with MPFL reconstruction, and the other 39 patients were treated non-surgically. The main outcome variable was patellar redislocation within a two year follow-up period. The Kujala questionnaire was applied for analyzing the pain and the quality of life. The additional surgeries due to patellofemoral problems were also recorded. RESULTS: Patellar redislocation occurred in eight patients in the non-surgical group, while no redislocation occurred in the surgical group (P < 0.05). Four patients in non-surgical group underwent further surgery due to patellar redislocation and poor function during the follow-up period. The Kujala score and the percentage of "good/excellent" results on the Kujala score of the surgical group were significantly better than that of the non-surgical group (P < 0.05). CONCLUSIONS: The surgical MPFL reconstruction achieved better clinical outcomes compared with non-surgical treatment for the acute primary patellar dislocation in the skeletally mature patients with the presence of abnormal patellofemoral anatomy. Surgery should be considered as the better choice for these specific patients.

Incidence of deep venous thrombosis in Chinese patients undergoing arthroscopic knee surgery for cruciate ligament reconstruction.

PURPOSE: This study investigated the incidence of deep venous thrombosis (DVT) in patients undergoing arthroscopic cruciate ligament surgery. METHODS: A total of 282 patients were examined by color Doppler ultrasound preoperatively and 3 and 7 days postoperatively. RESULTS: DVT was present in 34 of 282 patients (12.1 %); of these, 11 (32.6 %) underwent reconstruction of the anterior cruciate ligament (ACL), alone or in conjunction with the medial or lateral collateral ligament (MCL or LCL, respectively; 17.6 %); eight (23.5 %) of the posterior cruciate ligament (PCL); four (11.8 %) of the PCL-MCL/LCL; and five (14.7 %) of the ACL-MCL. In patients with tourniquets applied for <90, 90-120, and >120 min, the incidence of DVT was 5.6, 12.8, and 17.4 %, respectively. CONCLUSION: The incidence of DVT in normal patients undergoing ACL surgery was 12.1 %. A higher incidence was observed among cases of multiligament reconstruction, especially those involving the PCL, as well as in patients with tourniquets applied for more than 2 h. Based on these findings, prophylactic measures for DVT may be considered after arthroscopic knee surgery in order to decrease the incidence of DVT if specific risk factors are present. LEVELS OF EVIDENCE: IV.

Surgical versus non-surgical management for primary patellar dislocations: an up-to-date meta-analysis.

The aim of this up-to-date meta-analysis was to compare the effects of surgical versus non-surgical treatment of patients following primary patellar dislocation and to provide the best evidence currently available. A comprehensive literature search was conducted using multiple databases, including Medline, Embase, and Cochrane Registry of Clinical Trials. All databases were searched from the earliest records to May 2013. Eligible studies were selected, and data were extracted by two independent investigators. The primary outcome variable was the frequency of recurrent patellar dislocation. The other outcomes included knee function scores, patient-rated outcomes, and radiographic examination. If appropriate, meta-analysis of these variables was performed. Nine independent trials were found to match the inclusion criteria. The pooled results demonstrated that the incidence of recurrent patellar dislocation and Hughston visual analog scale was significantly lower in the surgical treatment group than that in the non-surgical treatment group (P < 0.05). There was no statistically significant difference between the two treatment groups in frequency of subsequent surgical interventions, percentage of excellent or good subjective opinion, Kujala score, pain score on visual analog scale, and severity of patellofemoral joint osteoarthrosis (P > 0.05). This up-to-date meta-analysis indicates that surgical treatment was associated with a lower risk of recurrent patellar dislocation, but a lower Hughston VAS than non-surgical treatment for primary patellar dislocation. More large high-quality trials and further studies are needed to overcome the limitations of small sample sizes, and varieties of different surgical procedures or non-surgical management strategies adopted in the included trials.

Analysis of the main indicators and risk factors of ultrasonic shear wave elastography for the diagnosis of osteoarthritis among adults.

Objective: This study was conducted to explore the main indicators of ultrasonic shear wave elastography (SWE) for the diagnosis of osteoarthritis (OA) and its influencing factors. Methods: We collected 910 patients between January 2018 and November 2023 from the department of ultrasound, Third Hospital of Hebei Medical University. Logistic regression was used to analyze the effects of age, gender, body mass index (BMI), smoking, alcohol, hypertension and diabetes on the diagnosis of OA by SWE. Results: The results showed that medial meniscal projection distance (MMPD) and OA had a positively correlated dose-response relationship (OR = 2.12, 95%CI (1.53, 3.95), trend p < 0.05). Also, medial meniscus elastometry (MME) had a positive dose-response correlation with OA (OR = 8.98, 95%CI (3.89, 11.52), trend p < 0.05). In addition, regarding the analysis of factors influencing the diagnosis of OA, the risk of OA was significantly higher in the older age group [OR = 1.11, 95%CI (1.01, 1.25)], and the risk of diagnosis in OA was high in the high BMI group [OR = 1.8, 95%CI (1.23, 3.01)]. Conclusion: In diagnosing OA, MMPD and MME can be used as reliable indicators, while people of advanced age and high BMI have a high possibility diagnosed with OA.

Clinical Use of Tranexamic Acid in High Tibial Osteotomy: A Systematic Review and Meta-analysis.

Background: High tibial osteotomy (HTO) can cause postoperative hemorrhage. The use of tranexamic acid to reduce the hemorrhage is still controversial. Purpose: To investigate the efficacy and safety of tranexamic acid in HTO. Study Design: Systematic review; Level of evidence, 4. Methods: Using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, the authors conducted a comprehensive search of the Embase, Cochrane Library, PubMed, Web of Science, MEDLINE, and Foreign Medical Literature Retrieval Service databases between their inception and January 1, 2023. All clinical studies comparing the use of tranexamic acid versus no tranexamic acid during HTO were collected. The primary outcome measures were hemoglobin decrease, drainage volume, and blood loss, and the secondary outcome measures were wound complications, blood transfusion, and postoperative thrombosis. All indicators were analyzed using meta-analysis software. Results were reported as mean differences or risk ratios with 95% confidence intervals. Results: Of 152 initial results, 9 studies involving 908 patients were included. The tranexamic acid group had lower indicators for total blood loss, hemoglobin decrease, and total drainage volume (P < .00001 for all). There were no differences between patients with versus without tranexamic acid in wound complications, including hematoma (P = .21) or infection (P = .18), nor were there any group differences in the prevalence of blood transfusion (P = .21) or postoperative thrombosis (P = .36). Conclusion: Tranexamic acid was able to effectively reduce postoperative hemorrhage in patients undergoing HTO without affecting the rates of wound complications, blood transfusion, or postoperative thrombosis.

Solitary Scapular Metastasis as the First Presentation of Prostate Adenocarcinoma Identified on 99mTc-MDP SPECT/CT.

ABSTRACT: Metastases of prostate carcinoma in the skeleton are usually multiple. Solitary metastasis in appendicular skeleton is extremely rare. We present bone scan findings of solitary scapular metastasis from prostate adenocarcinoma as the initial presentation of his malignancy in a 62-year-old man. The 99mTc-MDP SPECT/CT demonstrated intense activity in the coracoid process of left scapula, whereas the tracer uptakes in other bones were not typical of metastases. The subsequent pathological results of the punctured left scapula confirmed as metastasis from prostate adenocarcinoma.

The efficacy of the leg swing and quadriceps strengthening exercises versus platelet-rich plasma and hyaluronic acid combination therapy for knee osteoarthritis: A retrospective comparative study.

The aim of this was to investigate the efficacy of physical exercise (leg swing and quadriceps strengthening exercises) versus platelet-rich plasma (PRP) and hyaluronic acid (HA) combination therapy. From January 2020 to August 2021, 106 patients with Kellgren-Lawrence Grade I-III knee osteoarthritis were divided into leg swing and quadriceps strengthening exercises (Group A) and intra-articular combination injections of PRP and HA (Group B) according to the treatment strategies. Patients in Group A received regular leg swing and quadriceps strengthening exercises for 3 months. Patients in Group B received 2 intra-articular combination injections of PRP (2 mL) and HA (2 mL) every 2 weeks. The primary outcome measures were the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities (WOMAC) score. Secondary outcomes included single leg stance test and functional activity by 2-minute walk test and time up and go test. All outcomes were evaluated at baseline and again 1, 3, 6, and 12 months. The VAS and WOMAC scores were similar in both groups at 1 and 3 months after treatment (P > .05); however, Group A patients had significantly superior VAS and WOMAC scores than Group B patients at 6 and 12 months after treatment. For the single leg stance test, 2-minute walk test, and time up and go test, Group A patients were significantly superior to Group B throughout follow-up (P < .001). The leg swing and quadriceps strengthening exercises resulted in a significantly better clinical outcomes than the combined PRP and HA therapy, with a sustained lower pain score and improved quality of life, balance ability, and functional activity within 12 months.

A Sagittal Patellar Angle Linear Equation Reflecting Patellofemoral Kinematics: Evaluation of Patellar Height at any Degree of Knee Flexion Angle.

OBJECTIVE: To confirm whether a novel sagittal patellar angle linear equation used for evaluating patellar height by calculating expected sagittal patellar angle (SPA) at any degree of knee flexion angle is suitable for patients older than 17 years and its reliability compared with other commonly used methods. METHODS: From September 2016 to September 2019, a total number of 202 consecutive outpatients' knee lateral X-ray radiographs were retrospectively measured and evaluated using a recently proposed linear equation Y = 1.94 + 0.74 × knee flexion(KF) angle. Patients were divided by ages into ayounger group, whose ages were between 17-49 years, and an older group, whose ages were older than 49 years, which has not been validated in the original study. Parameters such as KF, SPA, patella and patella tendon length and so on were measured on computer with picture archiving and communication system by two independent observers at an interval of 1 month. Insall-Salvati (IS) index, Caton-Deschamps (CD) index and Y value, correlation coefficients were calculated and compared using SPSS 22.0 software. RESULTS: In the younger group, 143 patients (165 knees) were included, ages were 17-49 (31.62 ± 11.38) years, males/females were 70 (48.95%)/73 (51.05%), left knees/right knees were 83 (50.30%)/82 (49.70%), mean value of Y was 31.50° ± 10.07°, and SPA was 34.38° ± 12.38°, mean value of IS was 1.06 ± 0.17, mean value of CD was 1.04 ± 0.18. While in older group, 59 patients (78 knees) were included, ages were 50-60 (mean 54.61 ± 2.99) years, there were 32 males (54.24%) and 27 females (45.76%), 42 knees were left (53.85%) and 36 knees were right (46.15%), mean values of Y and SPA were 25.90° ± 11.55° and 29.36° ± 14.22°, mean IS index in older group was 1.06 ± 0.18, mean CD index was 1.00 ± 0.16. Intra- and inter-observer reliabilities of Y in younger and older groups were 0.999, 0.999, 1.000 and 0.999, meaning high reliability and reproducibility, but low Pearson's correlation coefficients with IS and CD index were showed as -0.213 and - 0.216 in younger group and - 0.113 and - 0.316 in older group. CONCLUSIONS: In patients older than 17 years, the linear equation Y = 1.94 + 0.74 × KF is a reliable and practical method to evaluate SPA regardless of age and knee flexion angle, but has weak correlation coefficients with the IS and CD index.

Depression mediates the relationship between smoking and pain: Evidence from a nationally representative study in a low- and middle-income country.

Evidence from high-income countries suggests that depressive symptoms may mediate the relationship between smoking and pain. However, the relationship remains poorly understood for the population in low- and middle-income countries (LMICs), who account for 80% of the current tobacco consumers. Using cross-sectional data from a nationally representative longitudinal survey in China, this study conducted the mediation analysis within the structural equation model (SEM) framework. It tested the indirect effect using the Monte Carlo method. Among the 16,575 participants, 29.2% (n = 4,839) reported being current smokers, 8.5% (n = 1,412) being former smokers, and 62.3% (n = 10,324) being never smokers. Phenotypic characteristics of smokers revealed some distinct characteristics concerning smoking rates, gender, and education attainment compared with results from high-income countries. Besides, current smokers reported significantly higher pain severity than never and former smokers and more depressive symptoms compared with never smokers. The mediation analysis indicated that the self-reported pain was mediated by depressive symptoms 62.7% of the association with smoking and 82.1% of the connection to the number of years quit. However, no mediation effect of depressive symptoms was found for the relationship between the amount smoked and pain severity. This study may fill the literature gap in examining depressive symptoms' mediating role in the relationship between smoking and pain severity for LMICs.

Exosomes derived from miRNA-210 overexpressing bone marrow mesenchymal stem cells protect lipopolysaccharide induced chondrocytes injury via the NF-κB pathway.

Bone marrow mesenchymal stem cells (BMSCs)-derived exosomes (Exos) have anti-inflammatory and anti-apoptotic functions. miRNA-210 has also been confirmed to play a role in inhibiting proinflammatory cytokines. Herein, we aimed to explore the effects of Exos derived from miRNA-210-overexpressing BMSCs (BMSCs-210-Exos) and the mechanisms by which they provide protection to chondrocytes from lipopolysaccharide (LPS)-induced injury. BMSCs were transfected with or without miRNA-210. Exos substantially improved the proliferation of chondrocytes and inhibited LPS-induced cell apoptosis. Furthermore, BMSCs-210-Exos promoted the proliferation of chondrocytes and prevented LPS-induced cell apoptosis better than BMSCs-Exos not overexpressing miRNA-210. In addition, tumor necrosis factor receptor superfamily member 21 (Tnfrsf21) expression was inhibited and the NF-κB pathway was attenuated by both BMSCs-Exos and BMSCs-210-Exos during LPS-induced chondrocyte injury. Collectively, these results suggest that BMSCs-210-Exos enhance the protection of chondrocytes from LPS-induced injury via the NF-κB pathway.

Melatonin Promotes Neuroprotection of H2O2-induced Neural Stem Cells via lncRNA MEG3/miRNA-27a-3p/MAP2K4 axis.

Melatonin is crucial for protecting neural stem cells (NSCs) from reactive oxygen species (ROS). However, the mechanism underlying these processes is unclear. In this study, we first investigated the significantly upregulated lncRNA MEG3 biomarker in the H2O2-induced NSCs and control groups. Melatonin inhibited the expression of MEG3 by methylation. MEG3 overexpression reversed the positive effects of melatonin on NSCs against H2O2. Furthermore, MEG3 reduced the expression levels of its targeted miRNA-27a-3p, which could be considered a neuroprotective effect. In addition, the elevated miRNA-27a-3p decreased JNK phosphorylation by targeting MAP2K4. Overexpression of MAP2K4 suppressed the neuroprotective effects of miRNA-27a-3p. Therefore, melatonin appeared to protect NSCs from H2O2-induced ROS by modification of the MEG3/miRNA-27a-3p/MAP2K4 axis.

Clinical outcomes and second-look arthroscopic findings of anterior cruciate ligament reconstruction with autograft, hybrid graft, and allograft.

BACKGROUND: There is no consensus as to the choice of grafts for primary anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to compare the clinical and second-look arthroscopic outcomes after ACL reconstruction by use of autograft, hybrid graft, and γ-irradiated allograft. METHODS: Ninety-seven patients who underwent second-look arthroscopy after ACL reconstruction with autografts (28 patients, hamstring autograft), hybrid grafts (32 patients, hamstring autograft augmented with γ-irradiated tibialis anterior tendon allograft), or γ-irradiated allografts (37 patients, tibialis anterior tendons) were included in this study. The clinical outcomes were compared by using Lysholm score, International Knee Documentation Committee (IKDC) score, and Tegner activity score, and the side-to-side differences of KT-1000 measurement. Second-look arthroscopic findings were compared in terms of synovial coverage and graft tension. RESULTS: There were no statistical significances among the three groups in Lysholm score, IKDC score, or Tegner activity score (P > 0.05). The KT-1000 examination showed more anterior laxity in the γ-irradiated allograft group than in the autograft or hybrid graft groups (P = 0.006, and P = 0.013, respectively). Two patients in the autograft group, 2 patients in the hybrid graft group and 4 patients in the allograft group were evaluated as graft failure on second-look arthroscopy. The synovial coverage was superior in the autograft group than that in the hybrid graft group or the allograft group (P = 0.013 and P = 0.010, respectively), and was comparable between the hybrid graft group and allograft group (P = 0.876). With regard to graft tension, the autograft group and hybrid group were comparable (P = 0.883) but showed better results than the allograft group (P = 0.011 and P = 0.007, respectively). CONCLUSION: The hamstring autografts and hybrid grafts used for ACL reconstruction produced equal efficacy but provided better knee stability than allografts. In addition, the hamstring autografts showed better synovial coverage than the other two graft types.

Effects of graft preconditioning on γ-irradiated deep frozen tendon allografts used in anterior cruciate ligament reconstruction.

Preconditioning of the grafts prior to implantation into the knee is considered to reduce the loss of tension caused by graft viscoelasticity after anterior cruciate ligament reconstruction. The present study analyzed the impacts of different preconditioning forces on the biomechanical properties of the γ-irradiated deep frozen tendon allografts. A total of 36 tendon grafts were randomly divided into three groups and were preconditioned at 80 N (group 1), 160 N (group 2) and 320 N (group 3) for 10 min. Subsequently, the grafts were gradually completely relaxed for 1 min and subsequently received 25 cyclic loads of 0-80 N. Afterwards, the grafts were loaded to 80 N, which was maintained for 30 min. Finally, load was gradually increased until ultimate failure at maximum load (UFML) was obtained. There were significant differences in the stiffness and UFML values between the 3 groups (all P<0.05). The graft stiffness in group 3 significantly increased compared with the other 2 groups, and the stiffness of group 2 grafts increased compared with group 1. The UFML in group 3 was significantly lower compared with groups 1 and 2, while there was no significant difference between groups 1 and 2. In the present study, the results suggested that increasing the initial tension could effectively reduce the loss of stiffness due to viscoelasticity for the γ-irradiated deep frozen allogeneic tendon grafts. However, overloaded initial tension decreased the tensile strength.

Medial collateral ligament reconstruction using bone-patellar tendon-bone allograft for chronic medial knee instability combined with multi-ligament injuries: a new technique.

BACKGROUND: The medial collateral ligament (MCL) is the main static stabilizer of the medial knee. The surgical treatment was recommended in cases with serious medial collateral ligament insufficiency combined with multi-ligament injuries and chronic symptomatic medial instability. Several surgical techniques have been described for the MCL reconstruction, while potential problems including donor site morbidity, complicated procedure, and high risk of femoral tunnel collision were reported. In order to minimize such potential limitations, we describe a new medial reconstruction technique for MCL injury using bone-patellar tendon-bone (BPTB) allograft. METHODS: A longitudinal incision at the medial knee was made. The centers of femoral and tibial attachments were gained through repeated isometricity test. Then, the bone grooves were made around the femoral and tibial centers. The appropriate BPTB allograft was selected, and both ends were trimmed. The prepared bone blocks were embedded into the grooves and fixed with cancellous screws. The programmed rehabilitation exercises were performed after the operation. RESULTS: A strong graft and bone-to-bone healing on both femoral and tibial attachment sites were obtained, and femoral tunnel collision during multi-ligament reconstruction was avoided. Satisfactory valgus and rotatory stability were gained. CONCLUSIONS: This novel MCL reconstruction technique using BPTB allograft can be safely performed, and the clinical outcome was favorable with satisfactory valgus and rotatory stability. More cases and additional follow-up results are needed to verify the overall effect of this technique.