Lateral femoral tunnel preparation and graft fixation for anterior cruciate ligament reconstruction–A discussion

This article provides a discussion and commentary around the recent advances in arthroscopic anterior cruciate ligament reconstruction(ACLR),with a focus on the aspects of lateral femoral tunnel preparation and graft fixation techniques.The paper explores and comments on a recently published review by Dai et al,titled"Research progress on preparation of lateral femoral tunnel and graft fixation in ACLR",while providing insight into its relevance within the field of ACLR,and recommendations for future research.

In vitro performance of a biodegradable zinc alloy adjustable-loop cortical suspension fixation for anterior cruciate ligament reconstruction

Anterior cruciate ligament(ACL)injuries of the knee are one of the most common and serious athletic injuries.The widely used cortical suspension fixation buttons for ligament reconstruction are permanent implants,particularly those made from conventional steel or titanium alloys.In this study,a biodegradable Zn-0.45Mn-0.2Mg(ZMM42)alloy with the yield strength of 300.4 MPa and tensile strength of 329.8 MPa was prepared through hot extrusion.The use of zinc alloys in the preparation of cortical suspension fixation buttons was proposed for the first time.After 35 d of immersion in simulated body fluids,the ZMM42 alloy fixation buttons were degraded at a rate of 44μm/a,and the fixation strength was retained(379.55 N)in the traction loops.Simultaneously,the ZMM42 alloy fixation buttons exhibited an increase in MC3T3-E1 cell viability and high antibacterial activity against Escherichia coli and Staphylococcus aureus.These results reveal the potential of biodegradable zinc alloys for use as ligament reconstruction materials and for developing diverse zinc alloy cortical suspension fixation devices.

Osteotomy combined with anterior cruciate ligament reconstruction for anterior cruciate ligament injury and biplanar deformity

BACKGROUND It has been confirmed that the increased posterior tibial slope over 12 degrees is a risk factor for anterior cruciate ligament injury,and varus deformity can aggravate the progression of medial osteoarthritis.AIM To evaluate the efficacy of modified high tibial osteotomy(HTO)and anterior cruciate ligament reconstruction(ACLR)in the treatment of anterior cruciate ligament(ACL)injuries with varus deformities and increased posterior tibial slope(PTS)based on clinical and imaging data.METHODS The patient data in this retrospective study were collected from 2019 to 2021.A total of 6 patients were diagnosed with ACL injury combined with varus deformities and increased PTS.All patients underwent modified open wedge HTO and ACLR.The degree of correction of varus deformity and the PTS was evaluated by radiography and magnetic resonance imaging.RESULTS All 6 patients(6 knee joints)were followed up for an average of 20.8±3.7 months.The average age at surgery was 29.5±3.8 years.At the last follow-up,all patients resumed competitive sports.The International Knee Documentation Committee score increased from 50.3±3.1 to 87.0±2.8,the Lysholm score increased from 43.8±4.9 to 86±3.1,and the Tegner activity level increased from 2.2±0.7 to 7.0±0.6.The average movement distance of the tibia anterior translation was 4.8±1.1 mm,medial proximal tibial angle(MPTA)was 88.9±1.3°at the last follow-up,and the PTS was 8.4±1.4°,both of which were significantly higher than those before surgery(P<0.05).CONCLUSION Modified open wedge HTO combined with ACLR can effectively treat patients with ACL ruptures with an associated increased PTS and varus deformity.The short-term effect is significant,but the long-term effect requires further follow-up.

Anterior cruciate ligament reconstruction:Effect of graft tunnel position on early to mid-term clinical outcomes

BACKGROUND Patient reported outcome measures(PROMs)can be used to assess knee function following anterior cruciate ligament(ACL)reconstruction.Intra-operatively,femoral and tibial tunnels are created to accommodate the new ACL graft.It is postulated that there is an optimum position and orientation of these tunnels and that outcomes from this procedure are affected by their position.AIM To evaluate the influence of graft tunnel position on early to mid-term clinical outcomes following ACL reconstruction.METHODS Six PROMs were collected following ACL reconstruction which included the Knee Injury and Osteoarthritis Outcome Score(KOOS),International Knee Documentation Committee,Lysholm,Tegner,EuroQol-5 Dimension-5 level,and Short Form 12-item Health Survey.A total of 8 radiological parameters were measured from post-operative X-rays relating to graft tunnel positions.This data was analysed to assess for any correlations between graft tunnel position and postoperative PROMs.RESULTS A total of 87 patients were included in the study with a mean post-operative follow-up of 2.3 years(range 1 to 7 years).Posterior position of tibial tunnel was associated with improved KOOS quality of life(rho=0.43,P=0.002)and EQ-5D VAS(rho=0.36,P=0.010).Anterior position of EndoButton femoral tunnel was associated with an improved EQ-5D index(rho=-0.38,P=0.028).There were no other significant correlations between any of the other radiological parameters and PROM scores.CONCLUSION Overall,graft tunnel position had very little correlation with clinical outcomes following ACL reconstruction.A few(posterior)tibial tunnel and(anterior)EndoButton femoral tunnel measurements were associated with better PROMs.

Cyclops syndrome following anterior cruciate ligament reconstruction: Can relapse occur after surgery?

Symptomatic cyclops lesions are complications that can be seen at rates of up to approximately 10%after anterior cruciate ligament reconstruction.However,recurrent cyclops lesions have rarely been documented.There are case rare series in the literature regarding the treatment of recurrent cyclops lesion.Future large studies are needed to investigate factors contributing to the development of cyclops lesions and syndrome and treatment options.

Recurrent cyclops lesion after primary resection of fibroreactive nodule following anterior cruciate ligament reconstruction

In this case report featured in World Journal of Orthopedics,Kelmer et al describe a rare finding of a 28-year-old female patient who presented with a recurrent fibroreactive nodule 7 months following the resection of a primary cyclops lesion,suggesting recurrent cyclops syndrome.The patient had undergone an initial anterior cruciate ligament reconstruction for a non-contact right knee injury and reported successful recovery.Two years later,the patient sustained a repeat right knee injury followed by a positive McMurray test and acute pain with terminal extension.Arthroscopic synovectomy confirmed magnetic resonance imaging(MRI)finding of a cyclops lesion,which was surgically removed.Seven months postoperatively,the patient reported stiffness and difficulty with terminal extension.Repeat MRI indicated a recurrent cyclops lesion,which was surgically resected.Following resection of the second lesion,the patient underwent physical therapy and achieved full range of motion,maintaining complete recovery 19 months postoperatively.Recurrent cyclops lesions have rarely been reported in the literature,and this article is novel in its report of recurrent cyclops syndrome following a bone-patellar tendon-bone allograft.The presentation of this unusual finding exposes a need for further investigation of cyclops lesion pathology,which will aid its prevention and treatment.

Recent research progress from biological perspective on the mechanism of formation of osteoarthritis after anterior cruciate ligament injury

The anterior cruciate ligament(ACL)mainly plays a role in stabilizing the knee joint by limiting the forward translation of tibial force and rotational force at the tibial joint,and if this ligament is damaged,it will cause joint pain,limited mobility,knee instability,etc.According to related studies,the incidence of traumatic osteoarthritis(PTOA)after ACL injury is as high as 87%,although many studies have shown that patients with ACL injury are susceptible to PTOA,but the exact mechanism is currently unknown.This may be related to biological,structural,and mechanical factors caused by the ligament injury.Previous studies have shown that elevated inflammatory mediators in the joint cavity following ACL injury can lead to chondrocytes necrosis and degradation of the cartilage matrix.These potential biochemical mediators contribute to PTOA formation,and early intervention can reduce future episodes of PTOA.In recent years,many scholars have devoted themselves to studying the potential important factors and signaling pathways involved in the formation of osteoarthritis after ACL injury,and exploring its molecular mechanism,which has led to great progress in this field.This paper mainly studies and discusses the mechanism of osteoarthritis formation after ACL injury from the biological perspective.

The Prevalence Type of the Meniscus Tear in Patients with Anterior Cruciate Ligament (ACL) Injury, in Abu Arish General Hospital, Jazan, KSA

Background: The anterior cruciate ligament (ACL) is the main structure that prevents the forward movement of the tibia about the femur Meniscus tear which is a common finding in patients with anterior cruciate ligament (ACL) injury. Aim: To investigate the prevalence of types of meniscus tears in patients with Anterior Cruciate Ligament (ACL) Injury. Methods: A retrospective study was conducted among inpatients. Clinical evaluation included side-to-side difference in anterior tibial translation (ATT) as measured by a KT-1000 arthrometer (MEDmetric Corp) and a grade of pivot-shift test at final follow-up in all patients. Subsequent meniscal tear was defined by symptoms of joint line pain and/or locking or joint effusion requiring surgical treatment. Results: Most of patients were males (92.6%). The patients were categorized into 5 groups according to age with a mean of age 32.8 ± 10.6. The most common causes of ACL injury were falling down (43.2%), trauma (38.1%) or knee torsion (18.8%). Medial meniscal tear was found in 92 knees (55.7%), while lateral meniscal tear was found in 19 knees (10.8%) and the most common type was the longitudinal tear that was found in 31 knees (17.6%). Similarly, 66.7% of the meniscal flap tears and half of the meniscal bucket-handle tears were significantly associated with loose body (P Conclusion: The present study demonstrated that meniscus tears are more common in individuals with chronic ACL rupture. The main factors contributing to ACL injury were classified as falls, trauma, and knee torsion. Gender was identified as a critical determinant in the etiology of ACL injury. The occurrence of a ramp lesion was associated longitudinal meniscal tears, whereas chodoral injury was associated with the majority of meniscal flap tears and meniscal bucket-handle tears.

Recurrent cyclops lesion after primary anterior cruciate ligament reconstruction using bone tendon bone allograft:A case report

BACKGROUND Cyclops lesions are a known complication of anterior cruciate ligament(ACL)reconstruction,with symptomatic cyclops syndrome occurring in up to 11%of surgeries.Recurrent cyclops lesions have been rarely documented;this case study documents the successful treatment of a recurrent cyclops lesion.CASE SUMMARY A 28-year-old female presented following a non-contact injury to the right knee.Workup and clinical exam revealed an ACL tear,and arthroscopic reconstruction was performed.Two years later a cyclops lesion was discovered and removed via arthroscopic synovectomy.Seven months postoperatively,the patient presented with pain,stiffness,and difficulty achieving terminal extension.A smaller recurrent cyclops lesion was diagnosed,and a repeat synovectomy was performed.The patient recovered fully.CONCLUSION To the best of our knowledge,this is the first documented case of recurrent cyclops lesion after bone-patellar tendon-bone allograft ACL reconstruction presenting as cyclops syndrome.

Research progress on preparation of lateral femoral tunnel and graft fixation in anterior cruciate ligament reconstruction

Anterior cruciate ligament(ACL)injury is one of the most common types of sports injuries.People’s need to participate in sports and desire for a high quality of life promotes the continuous development of ACL reconstruction technology.Arthroscopic ACL reconstruction has been recognized as an effective method for the treatment of ACL injuries.This review analyses and summarizes the advantages and limitations of each surgical procedure for arthroscopic ACL reconstruction reported in the relevant literature so as to promote the future development of more relevant techniques.

Comparative study of the clinical efficacy of all-inside and traditional techniques in anterior cruciate ligament reconstruction

BACKGROUND Many studies have focused on the femoral tunnel technique and fixation method,but few studies have involved the tibial tunnel technique and fixation method.The all-inside technique is one of the new techniques that has been described in recent years.All-inside anterior cruciate ligament(ACL)reconstruction is based on a tibial socket instead of a full tunnel.This method has many potential advantages.AIM To compare clinical outcomes of knee ACL autograft reconstruction using allinside quadrupled semitendinosus(AIST)and traditional hamstring tendon(TBT)techniques.METHODS From January 2017 to October 2019,the clinical data of 80 patients with ACL reconstruction were retrospectively analyzed,including 67 males and 13 females.The patients had an average age of 24.3±3.1 years(age range:18-33 years).The AIST technique was used in 42 patients and the TBT technique was used in 38 patients.The time between operation and injury,operative duration,postoperative visual analogue scale(VAS)score and knee functional recovery were recorded and compared between the two groups.The International Knee Documentation Committee(IKDC)and Lysholm scoring system were used to comprehensively evaluate clinical efficacy.RESULTS Eighty patients were followed for 24-36 mo,with an average follow-up duration of 27.5±1.8 mo.There were no significant differences in the time between surgery and injury,operative duration,IKDC and Lysholm scores of the affected knee at the last follow-up evaluation between the two groups.There were significant differences in VAS scores 1 d,3 d,7 d,2 wk and 1 mo after surgery(P<0.05).There was no significant difference in VAS score at 3 mo,6 mo and 1 year after operation.CONCLUSION The efficacy of the AIST ACL reconstruction technique was comparable to the TBT technique,but the postoperative pain was less with the AIST technique.Thus,the AIST technique is an ideal treatment choice for ACL reconstruction.

Demographic characteristics of patients who underwent anterior cruciate ligament reconstruction at a tertiary care hospital in India

BACKGROUND Anterior cruciate ligament(ACL)tears are common sports-related injuries.Their incidence is not the same either for all the sports or for the same sport across various nations.This information is maintained by many sports leagues in their registries.However,very few nationwide registries exist for such injuries.This study is carried out to know the demographic characteristics of patients who underwent ACL reconstruction at our hospital in India.AIM To know the demographic characteristics of patients who underwent ACL reconstruction at a tertiary care hospital in India.METHODS All the patients who underwent ACL reconstruction from January 2020 to December 2021 were retrospectively studied.Patients with multi-ligament injuries or a history of previous knee surgery were excluded.The patients’history was obtained from the hospital records,they were interviewed telephonically,and online questionnaires were given.Their demographic data was analyzed and compared to the existing literature.RESULTS A total of 124 patients were operated on for ACL reconstruction during this period.The mean age of the patients was 27.97 years.One hundred and thirteen patients(91.1%)were male and 11(8.9%)were female.The majority of the patients(47.6%)sustained this injury by road traffic accidents(RTA)followed by sportsrelated injuries(39.5%).The commonest presenting complaint was giving way of the knee in 118 patients(95.2%).The mean duration from the injury to the first hospital visit among the patients was 290.1 d.The mean duration from the injury to surgery was 421.8 d.CONCLUSION ACL patients’demography is different in developing nations as compared to the developed world.RTA are the leading cause of ACL injuries and are followed by recreational sports as a cause.There is delayed access to healthcare leading to delayed diagnosis as well as even greater time to surgery.This,in turn,leads to poorer prognosis and longer rehabilitation.National registries for developing nations are the need of the hour due to the different demographics of ACL injuries in developing countries.

Assessment of functional prognosis of anterior cruciate ligament reconstruction in athletes based on a body shape index

BACKGROUND A healthy body shape is essential to maintain athletes’sports level.At present,little is known about the effect of athletes’body shape on anterior cruciate ligament reconstruction(ACLR).Moreover,the relationship between body shape and variables such as knee joint function after operation and return to the field has not been well studied.AIM To verify the relationship between a body shape index(ABSI)and the functional prognosis of the knee after ACLR in athletes with ACL injuries.METHODS We reviewed 76 athletes with unilateral ACL ruptures who underwent ACLR surgery in the First Hospital of Shanxi Medical University between 2017 and 2020,with a follow-up period of more than 24 mo.First,all populations were divided into a High-ABSI group(ABSI>0.835,n=38)and a Low-ABSI group(ABSI<0.835,n=38)based on the arithmetic median(0.835)of ABSI values.The primary exposure factor was ABSI,and the outcome indicators were knee function scores as well as postoperative complications.The correlation between ABSI and postoperative knee function scores and postoperative complications after ACLR were analyzed using multifactorial logistic regression.RESULTS The preoperative knee function scores of the two groups were similar.The surgery and postoperative rehabilitation exercises,range of motion(ROM)compliance rate,Lysholm score,and Knee Injury and Osteoarthritis Outcome Score of the two groups gradually increased,whereas the quadriceps atrophy index gradually decreased.The knee function scores were higher in the Low-ABSI group than in the High-ABSI group at the 24-mo postoperative follow-up(P<0.05).In multifactorial logistic regression,ABSI was a risk factor of low knee joint function score after surgery,specifically low ROM scores(odds ratio[OR]=1.31,95%confidence interval[CI][1.10-1.44];P<0.001),low quadriceps atrophy index(OR=1.11,95%CI[0.97-1.29];P<0.05),low Lysholm scores(OR=2.34,95%CI[1.78-2.94];P<0.001),low symptoms(OR=1.14,95%CI[1.02-1.34];P<0.05),low activity of daily living(OR=1.34,95%CI[1.18-1.65];P<0.05),low sports(OR=2.47,95%CI[1.78-2.84];P<0.001),and low quality of life(OR=3.34,95%CI[2.88-3.94];P<0.001).ABSI was also a risk factor for deep vein thrombosis of the lower limb(OR=2.14,95%CI[1.88-2.36],P<0.05]and ACL recurrent rupture(OR=1.24,95%CI[0.98-1.44],P<0.05)after ACLR.CONCLUSION ABSI is a risk factor for the poor prognosis of knee function in ACL athletes after ACLR,and the risk of poor knee function after ACLR,deep vein thrombosis of lower limb,and ACL recurrent rupture gradually increases with the rise of ABSI.

Therapeutic effect of two methods on avulsion fracture of tibial insertion of anterior cruciate ligament

BACKGROUND The tibial stop of anterior cruciate ligament(ACL) is fan-shaped and attached to the medial groove in front of the intercondylar spine,which is located between the anterior horn of the medial and lateral meniscus.The incidence of this fracture is low previously reported,which is common in children and adolescents.With the increase of sports injury and traffic injury and the deepening of understanding,it is found that the incidence of the disease is high at present.AIM To explore the difference between open reduction and internal fixation with small incision and high-intensity non-absorbable suture under arthroscopy in the treatment of tibial avulsion fracture of ACL.METHODS Seventy-six patients with tibial avulsion fracture of anterior cruciate ligament diagnosed and treated in Guanyun County People’s Hospital from April 2018 to June 2020 were retrospectively analyzed.According to the surgical methods,they were divided into group A(40 cases) and group B(36 cases).Patients in group A were treated with arthroscopic high-strength non-absorbable suture,and patients in group B were treated with small incision open reduction and internal fixation.The operation time,fracture healing time,knee joint activity and functional score before and after operation,and surgical complications of the two groups were compared.RESULTS The operation time of group A was higher than that of group B,and the difference was statistically significant(P < 0.05);the fracture healing time of group A was compared with that of group B,and the difference was not statistically significant(P > 0.05);The knee joint function activity was compared between two groups before operation,3 mo and 6 mo after operation,and the difference was not statistically significant(P > 0.05);the knee joint function activity of group A and group B at 3 mo and 6 mo after operation was significantly higher than that before operation(P < 0.05);the limp,support,lock,instability,swelling,upstairs,squatting,pain and Lysholm score were compared between the two groups before and 6 mo after operation,and the difference was not statistically significant(P > 0.05);the scores of limp,support,lock,instability,swelling,upstairs,squatting,pain and Lysholm in group A and group B at 6 mo after operation were significantly higher than those before operation(P > 0.05);the surgical complication rate of group A was 2.63%,which was lower than 18.42% of group B,and the difference was statistically significant(P > 0.05).CONCLUSION Both small incision open reduction and internal fixation and arthroscopic high-strength nonabsorbable sutures can achieve good results in the treatment of anterior cruciate ligament tibial avulsion fractures.The operation time of arthroscopic high-strength non-absorbable sutures is slightly longer,but the complication rate is lower.

Principles of postoperative anterior cruciate ligament rehabilitation

It is known that anterior cruciate ligament(ACL) reconstruction needs to be combined with detailed postoperative rehabilitation in order for patients to return to their pre-injury activity levels, and that the rehabilitation process is as important as the reconstruction surgery. Literature studies focus on how early in the postoperative ACL rehabilitation period rehabilitation modalities can be initiated. Despite the sheer number of studies on this topic, postoperative ACL rehabilitation protocols have not been standardized yet. Could common, "ossified" knowledge or modalities really prove themselves in the literature? Could questions such as "is postoperative brace use really necessary?", "what are the benefits of early restoration of the range of motion(ROM)?", "to what extent is neuromuscular electrical stimulation(NMES) effective in the protection from muscular atrophy?", "how early can proprioception training and open chain exercises begin?", "should strengthening training start in the immediate postoperative period?" be answered for sure? My aim is to review postoperative brace use, early ROM restoration, NMES, proprioception, open/closed chain exercises and early strengthening, which are common modalities in the very comprehensive theme of postoperative ACLrehabilitation, on the basis of several studies(Level of Evidence 1 and 2) and to present the commonly accepted ways they are presently used. Moreover, I have presented the objectives of postoperative ACL rehabilitation in tables and recent miscellaneous studies in the last chapter of the paper.

Hamstring autograft utilization in reconstructing anterior cruciate ligament:Review of harvesting techniques,graft preparation,and different fixation methods

Rupture of the anterior cruciate ligament(ACL)is a common orthopedic injury.Various graft options are available for the reconstruction of ruptured ACL.Using the hamstring muscle as an autograft was first described in 1934,and it remains a commonly harvested graft for ACL reconstruction.Hamstring autografts can be harvested using the traditional anteromedial approach or the newer posteromedial technique.An isolated semitendinosus tendon can be used or combined with the gracilis tendon.There are numerous methods for graft fixation,such as intra-tunnel or extra-tunnel fixation.This comprehensive review discusses the different hamstring muscle harvesting techniques and graft preparation options and fixation methods.It provides a comprehensive overview for choosing the optimal surgical technique when treating patients.

Regeneration of the anterior cruciate ligament:Current strategies in tissue engineering

Recent advancements in the field of musculoskeletaltissue engineering have raised an increasing interest in the regeneration of the anterior cruciate ligament(ACL). It is the aim of this article to review the current research efforts and highlight promising tissue engineering strategies. The four main components of tissue engineering also apply in several ACL regeneration research efforts. Scaffolds from biological materials, biodegradable polymers and composite materials are used. The main cell sources are mesenchymal stem cells and ACL fibroblasts. In addition, growth factors and mechanical stimuli are applied. So far, the regenerated ACL constructs have been tested in a few animal studies and the results are encouraging. The different strategies, from in vitro ACL regeneration in bioreactor systems to bio-enhanced repair and regeneration, are under constant development. We expect considerable progress in the near future that will result in a realistic option for ACL surgery soon.

Effect of suspension training on neuromuscular function, postural control, and knee kinematics in anterior cruciate ligament reconstruction patients

BACKGROUND Suspension training(SET)is a method of neuromuscular training that enables the body to carry out active training under unstable support through a suspension therapy system.However,there have been few reports in the literature on the application of SET to anterior cruciate ligament reconstruction(ACLR)patients.It is not clear what aspects of the patient's function are improved after SET.AIM To investigate the effect of SET on the neuromuscular function,postural control,and knee kinematics of patients after ACLR surgery.METHODS Forty participants were randomized to an SET group or a control group.The SET group subjects participated in a SET protocol over 6 wk.The control group subjects participated in a traditional training protocol over 6 wk.Isokinetic muscle strength of the quadriceps and hamstrings,static and dynamic posture stability test,and relative translation of the injured knee were assessed before and after training.RESULTS The relative peak torque of the quadriceps and hamstrings in both groups increased significantly(P<0.001),and the SET group increased by a higher percentage than those in the control group(quadriceps:P=0.004;hamstrings:P=0.011).After training,both groups showed significant improvements in static and dynamic posture stability(P<0.01),and the SET group had a greater change than the control group(P<0.05).No significant improvement on the relative translation of the injured knee was observed after training in either group(P>0.05).CONCLUSION Our findings show that SET promotes great responses in quadriceps and hamstring muscle strength and balance function in ACLR patients.

Surgical treatment for a combined anterior cruciate ligament and posterior cruciate ligament avulsion fracture: A case report

BACKGROUND Independent avulsion fractures with anterior cruciate ligament(ACL)or posterior cruciate ligament(PCL)attachment are relatively common among tibial intercondylar eminence fractures,and their postoperative outcomes are generally favorable.Conversely,huge avulsion fractures of the intercondylar eminence containing the attachment site of both the ACL and the PCL are extremely rare,and the reported clinical outcomes are poor.CASE SUMMARY We describe a 30-year-old Japanese male's huge avulsion fracture of the intercondylar eminence of a tibia containing the attachment site of both the ACL and PCL,together with a complete tear of the medial collateral ligament and a partial tear of both the medial and lateral menisci caused by a fall from a high place.All of these injuries were treated surgically,with anatomical reduction and stable fixation.The limb function at 1 year post-surgery was excellent(Lysholm score:100 points).CONCLUSION Although this patient's complete surgical repair was complex,it should be performed in similar cases for an excellent final clinical outcome.

Enhancing the Surface Properties of a Bioengineered Anterior Cruciate Ligament Matrix for Use with Point-of-Care Stem Cell Therapy

We have previously developed a poly(L-lactic)acid(PLLA)bioengineered anterior cruciate ligament(ACL)matrix that has demonstrated enhanced healing when seeded with primary ACL cells prior to implantation in a rabbit model,as compared with the matrix alone.This suggests that improving cell adhesion on the matrix may beneficially affect the healing response and long-term performance of the bioengineered ACL matrix.One regenerative engineering approach involves enhancing the surface properties of the matrix to support cell adhesion and growth in combination with point-of-care stem cell therapy.Herein,we studied the cell adhesion properties of PLLA braided microfiber matrices enhanced through the physical adsorption of fibronectin and air plasma treatment.We evaluated the kinetics and binding efficiency of fibronectin onto matrices at three time points and three fibronectin concentrations.Incubating the matrix for 120 min in a solution of 25 lgmL1 fibronectin achieved the greatest binding efficiency to the matrix and cellular adhesion.Exposing the matrices to air plasma treatment for 5 min before fibronectin adsorption significantly enhanced the cell adhesion of rabbit bone marrow-derived mesenchymal stem cells(R-BMMSCs)24 h post cell seeding.Finally,cellular proliferation was monitored for up to 21 d,the matrices were exposed to air plasma treatment,and fibronectin adsorption was found to result in enhanced cell number.These findings suggest that exposure to air plasma treatment and fibronectin adsorption enhances the cellular adhesion of PLLA braided microfiber matrices and may improve the clinical efficacy of the matrix in combination with point-of-care stem cell therapies.