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.

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.

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.

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.

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.

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.

Biomechanical comparison of single-tunnel double-bundle and single-bundle reconstruction of anterior cruciate ligament

Objective To compare the difference in stability of the knee joint after single-tunnel double-bundle and single-bundle anterior cruciate ligament (ACL) reconstruction.Methods Six formalin-soaked specimens of the human knee with retained

Anterior cruciate ligament reconstruction best practice: A review of graft choice

There is much literature about differing grafts used in anterior cruciate ligament(ACL) reconstruction. Much of this is of poor quality and of a low evidence base. We review and summarise the literature looking at the four main classes of grafts used in ACL reconstruction; bone-patella tendon-bone, hamstrings, allograft and synthetic grafts. Each graft has the evidence for its use reviewed and then compared, where possible, to the others. We conclude that although there is no clear "best" graft, there are clear differences between the differing graft choices. Surgeon's need to be aware of the evidence behind these differences, in order to have appropriate discussions with their patients, so as to come to an informed choice of graft type to best suit each individual patient and their requirements.

Biomechanics of the anterior cruciate ligament:Physiology,rupture and reconstruction techniques

The influences and mechanisms of the physiology,rupture and reconstruction of the anterior cruciate ligament(ACL)on kinematics and clinical outcomes have been investigated in many biomechanical and clinical studies over the last several decades.The knee is a complex joint with shifting contact points,pressures and axes that are affected when a ligament is injured.The ACL,as one of the intra-articular ligaments,has a strong influence on the resulting kinematics.Often,other meniscal or ligamentous injuries accompany ACL ruptures and further deteriorate the resulting kinematics and clinical outcomes.Knowing the surgical options,anatomic relations and current evidence to restore ACL function and considering the influence of concomitant injuries on resulting kinematics to restore full function can together help to achieve an optimal outcome.

Anterior cruciate ligament reconstruction and knee osteoarthritis

Anterior cruciate ligament(ACL)injury is a traumatic event that can lead to significant functional impairment and inability to participate in high-level sports-related activities.ACL reconstruction is considered the treatment of choice for symptomatic ACL-deficient patients and can assist in full functional recovery.Furthermore,ACL reconstruction restores ligamentous stability to normal,and,therefore,can potentially fully reinstate kinematics of the knee joint.As a consequence,the natural history of ACL injury could be potentially reversed via ACL reconstruction.Evidence from the literature is controversial regarding the effectiveness of ACL reconstruction in preventing the development of knee cartilage degeneration.This editorial aims to present recent highlevel evidence in an attempt to answer whether ACL injury inevitably leads to osteoarthritis and whether ACL reconstruction can prevent this development or not.

Arterial complications, venous thromboembolism and deep venous thrombosis prophylaxis after anterior cruciate ligament reconstruction: A systematic review

AIM To summarize the current knowledge on vascular complications and deep venous thrombosis(DVT) prophylaxis after anterior cruciate ligament(ACL) reconstruction.METHODS A systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. MEDLINE, EMBASE, Cochrane,Web of Science, CINAHL, PubMed publisher, and Google scholar medical literature databases were searched up to November 10, 2015. Any arthroscopic surgical method of primary or revision intra-articular ACL reconstruction of all graft types in humans was included. A risk of bias assessment was determined.RESULTS Fourty-seven studies were included in the review.Pseudaneurysms were the most frequently reported arterial complication after ACL reconstruction, irrespective of graft type or method of graft fixation with an incidence of 0.3%. The time to diagnosis of arterial complications after ACL reconstruction varied from days to mostly weeks but even years. After ACL reconstruction without thromboprophylaxis, the incidence of DVT was 9.7%, of which 2.1% was symptomatic. The incidence of pulmonary embolism was 0.1%. Tourniquet time > 2 h was related to venous thromboembolism.Thromboprophylaxis is indicated in patients with risk factors for venous thromboembolism.CONCLUSION After ACL reconstruction, the incidence of arterial complications,symptomatic DVT and pulmonary embolism was 0.3%, 2.1% and 0.1% respectively. Arterial complications may occur with all types of arthroscopic ACL reconstruction, methods of graft fixation as well as any type of graft. Patients considered to be at moderate or high risk of venous thromboembolism should routinely receive thromboprophylaxis after ACL reconstruction.

Recurrent surgical site infection after anterior cruciate ligament reconstruction: A case report

BACKGROUND Surgical site infections following anterior cruciate ligament(ACL)reconstruction are an uncommon but potentially devastating complication.In this study,we present an unusual case of recurrent infection of the knee after an ACL reconstruction,and discuss the importance of accurate diagnosis and appropriate management,including the issue of graft preservation versus removal.CASE SUMMARY A 33-year-old gentleman underwent ACL reconstruction using a hamstring tendon autograft with suspensory Endobutton fixation to the distal femur and an interference screw fixation to the proximal tibia.Four years after ACL reconstruction,he developed an abscess over the proximal tibia and underwent incision and drainage.Remnant suture material was found at the base of the abscess and was removed.Five years later,he re-presented with a lateral distal thigh abscess that encroached the femoral tunnel.He underwent incision and drainage of the abscess which was later complicated by a chronic discharging sinus.Repeated magnetic resonance imaging revealed a fistulous communication between the lateral thigh wound extending toward the femoral tunnel with suggestion of osteomyelitis.Decision was made for a second surgery and the patient was counselled about the need for graft removal should there be intraarticular involvement.Knee arthroscopy revealed the graft to be intact with no evidence of intra-articular involvement.As such,the decision was made to retain the ACL graft.Re-debridement,excision of the sinus tract and removal of Endobutton was also performed in the same setting.Joint fluid cultures did not grow bacteria.However,tissue cultures from the femoral tunnel abscess grew Enterobacter cloacae complex,similar to what grew in tissue cultures from the tibial abscess five years earlier.In view of the recurrent and indolent nature of the infection,antibiotic therapy was escalated from Clindamycin to Ertapenem.He completed a six-week course of intravenous antibiotics and has been well for six months since surgery,with excellent knee function and no evidence of any further infection.CONCLUSION Prompt and accurate diagnosis of surgical site infection following ACL reconstruction,including the exclusion of intra-articular involvement,is important for timely and appropriate treatment.Arthroscopic debridement and removal of implant with graft preservation,together with a course of antibiotics,is a suitable treatment option for extra-articular knee infections following ACL reconstruction.

Magnetic resonance imaging after anterior cruciate ligament reconstruction:A practical guide

Anterior cruciate ligament(ACL) reconstruction is one of the most common orthopedic procedures performed worldwide. In this regard, magnetic resonance imaging(MRI) represents a useful pre-operative tool to confirm a disruption of the ACL and to assess for potential associated injuries. However, MRI is also valuable postoperatively, as it is able to identify, in a non-invasive way, a number of aspects and situations that could suggest potential problems to clinicians. Graft signal and integrity, correct tunnel placement, tunnel widening, and problems with fixation devices or the donor site could all compromise the surgical outcomes and potentially predict the failure of the ACL reconstruction. Furthermore, several anatomical features of the knee could be associated to worst outcomes or higher risk of failure. This review provides a practical guide for the clinician to evaluate the post-surgical ACL through MRI, and to analyze all the parameters and features directly or indirectly related to ACL reconstruction, in order to assess for normal or pathologic conditions.

A Single Bundle Anterior Cruciate Ligament Reconstruction (ACL-R) Using Hamstring Tendon Autograft and Tibialis Anterior Tendon Allograft:A Comparative Study

The main purpose of this study patients undergoing a single bundle anterior was to compare the clinical outcomes of cruciate ligament reconstruction (ACL-R) of using quadrupled hamstring (4HT)autografts and two-strand tibialis anterior (2TA) aUografts,and to find out the rate of graft failure and possible causes.We hypothesized that there would be no difference in the clinical outcome,and graft failure would be associated with the use of small sized allograft in young active males with high demand of sports activities.We retrospectively evaluated 222 patients (male,n=167,female,n=55) undergoing ACL-R between January 2010 and July 2014.Of 222 patients,115 were included in the 4HT autograft group and 107 patients in the 2TA allograft group.Inclusion criteria were primary unilateral ACL-R with a minor MCL (<grade Ⅱ)injury with or without meniscus tear and had at least 2.5 years of follow-up.Subjective evaluation was performed using Tegner-Lysholm score,modified Cincinnati knee score,and IKDC knee form.Anteroposterior laxity was assessed using ADT and Lachman test whereas rotational laxity was assessed using pivot shift test.Similarly,functional assessment was performed using range of motion (ROM),Daniel's one-leg hop test,and overall IKDC score.Clinical outcomes were satisfactory and comparable in both groups with no statistically significant difference in all the respective parameters.No statistically significant difference was observed in graft re-rupture rate.However,most graft failures occurred in young active males with high demand of sports activities,graft size smaller than 8 mm,and use of allograft.An autograft with at least 8 mm diameter should be considered in a young active male with high demand of sports activities to avoid graft failure.

Anterior cruciate ligament reconstruction using a double bundle hamstring autograft configuration in patients under 30 years

BACKGROUND Anterior cruciate ligament reconstruction(ACLR)has a high incidence of re-tear in younger patients.Despite comparable functional outcomes,the incidence of retear using single and double bundle ACLR methods has not been well reported.AIM To hypothesize that double bundle hamstring ACLR has a lower graft rupture rate compared with single bundle hamstring ACLR grafts in young patients.METHODS One hundred and twelve patients<30 years of age at the time of primary double bundle ACLR were eligible for study participation.91(81.3%)could be contacted,with a mean age of 20.4 years(range 13-29)and mean post-operative follow-up time of 59 mo(range 25-107).Telephone questionnaires evaluated the incidence(and timing)of subsequent re-tear and contralateral ACL tear,further surgeries,incidence and time to return to sport,and patient satisfaction.RESULTS Of the 91 patients,there were 6(6.6%,95%CI:1.4-11.7)ACL graft re-ruptures,with a mean time to re-rupture of 28 mo(range 12-84).Fourteen patients(15.4%)experienced a contralateral ACL rupture and 14 patients(15.4%)required further surgery to their ipsilateral knee.fifty patients(54.9%)returned to pre-injury level of sport.Of those<20 years(n=45),4 patients(8.9%,95%CI:0.4-17.3)experienced a re-rupture,with mean time to re-injury 15 mo(range 12-24).Comparative analysis with existing literature and revealed a non-significant Chisquared statistic of 2.348(P=0.125).CONCLUSION A trend existed toward lower graft rupture rates in young patients undergoing double bundle ACLR utilizing a hamstring autograft,compared with rates reported after single bundle ACLR.

Depression and psychiatric disease associated with outcomes after anterior cruciate ligament reconstruction

While most patients with an anterior cruciate ligament(ACL) injury indicate satisfaction with surgical intervention, a significant proportion still do not return to pre-injury level of function or sport. Psychiatric comorbidities, such as depression, have recently been associated with poor clinical outcomes after ACL reconstruction(ACLR). To date, no article has yet examined how depression affects ACLR outcomes and how potential screening and intervention for psychological distress may affect postoperative activity level. The purpose of this review is to delineate potential relationships between depression and ACLR outcome, discuss clinical implications and identify future directions for research.

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.

Technical note: Anterior cruciate ligament reconstruction in the presence of an intramedullary femoral nail using anteromedial drilling

AIM To describe an approach to anterior cruciate ligament(ACL) reconstruction using autologous hamstring by drilling via the anteromedial portal in the presence of an intramedullary(IM) femoral nail.METHODS Once preoperative imagining has characterized the proposed location of the femoral tunnel preparations are made to remove all of the hardware(locking bolts and IM nail). A diagnostic arthroscopy is performed in the usual fashion addressing all intra-articular pathology. The ACL remnant and lateral wall soft tissues are removed from the intercondylar, to provide adequate visualization of the ACL footprint. Femoral tunnel placement is performed using a transportal ACL guide with desired offset and the knee flexed to 2.09 rad. The Beath pin is placed through the guide starting at the ACL's anatomic footprint using arthroscopic visualization and/or fluoroscopic guidance. If resistance is met while placing the Beath pin, the arthroscopy should be discontinued and the obstructing hardware should be removed under fluoroscopic guidance. When the Beath pin is successfully placed through the lateral femur, it is overdrilled with a 4.5 mm Endobutton drill. If the Endobutton drill is obstructed, the obstructing hardware should be removed under fluoroscopic guidance. In this case, the obstruction is more likely during Endobutton drilling due to its larger diameter and increased rigidity compared to the Beath pin. The femoral tunnel is then drilled using a best approximation of the graft's outer diameter. We recommend at least 7 mm diameter to minimize the risk of graft failure. Autologous hamstring grafts are generally between 6.8 and 8.6 mm in diameter. After reaming, the knee is flexed to 1.57 rad, the arthroscope placed through the anteromedial portal to confirm the femoral tunnel position, referencing the posterior wall and lateral cortex. For a quadrupled hamstring graft, the gracilis and semitendinosus tendons are then harvested in the standard fashion. The tendons are whip stitched, quadrupled and shaped to match the diameter of the prepared femoral tunnel. If the diameter of the patient's autologous hamstring graft is insufficient to fill the prepared femoral tunnel, the autograft may be supplemented with an allograft. The remainder of the reconstruction is performed according to surgeon preference. RESULTS The presence of retained hardware presents a challenge for surgeons treating patients with knee instability. In cruciate ligament reconstruction, distal femoral and proximal tibial implants hardware may confound tunnel placement, making removal of hardware necessary, unless techniques are adopted to allow for anatomic placement of the graft. CONCLUSION This report demonstrates how the femoral tunnel can be created using the anteromedial portal instead of a transtibial approach for reconstruction of the ACL.

Interspace between the Popliteal Artery and the Capsule of the Knee (IPACK) Block for Anterior Cruciate Ligament Reconstruction Surgery: A Two Case Series

This case series describes the use of Interspace between the Popliteal Artery and the Capsule of the Knee (IPACK) block to provide motor-sparing analgesia for two consecutive patients undergoing anterior cruciate ligament reconstruction (ACLR) by the same surgeon. Case 1 demonstrates the use of a proximal IPACK block as a post-operative rescue block for a patient who still experienced severe pain despite having received a femoral nerve block and parenteral opioids. Case 2 describes the use of a modified IPACK block as part of a multimodal approach with opioid and motor sparing effects. In both cases, the IPACK block provided satisfactory pain relief in the immediate postoperative period without motor weakness, making it an effective analgesic method for day surgery. With the IPACK block shown to be an effective nerve block for ACLR, we explore other advantages, limitations and further research required to better define the role of this block.