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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Allograft tissue irradiation and failure rate after anterior cruciate ligament reconstruction:A systematic review

AIM:To evaluate whether anterior cruciate ligament(ACL) allograft irradiation is effective for sterility without compromising graft integrity and increasing failure rate.METHODS:A literature search was conducted using Pub Med,Cochrane,and Google.The following search terms were used:"Gamma irradiation AND anterior cruciate ligament AND allograft" with a return of 30 items.Filters used included:English language,years 1990-2015.There were 6 hits that were not reviewed,as there were only abstracts available.Another 5 hits were discarded,as they did not pertain to the topic of interest.There were 9 more articles that were excluded:Three studies were performed on animals and 6 studies were meta-analyses.Therefore,a total of 10 articles were applicable to review.RESULTS:There is a delicate dosing crossover where gamma irradiation is both effective for sterility without catastrophically compromising the structural integrity of the graft.Of note,low dose irradiation is considered less than 2.0 Mrad,moderate dose is between 2.1-2.4 Mrad,and high dose is greater than or equal to 2.5 Mrad.Based upon the results of the literature search,the optimal threshold for sterilization was found to be sterilization at less than 2.2 Mrad of gamma irradiation with the important caveat of being performed at low temperatures.The graft selection process also must include thorough donor screening and testing as well as harvesting the tissue in a sterile fashion.Utilization of higher dose(≥ 2.5 Mrad) of irradiation causes greater allograft tissue laxity that results in greater graft failure rate clinically in patients after ACL reconstruction.CONCLUSION:Allograft ACL graft gamma irradiatedwith less than 2.2 Mrad appears to be a reasonable alternative to autograft for patients above 25 years of age.

Patient reported outcome measures in anterior cruciate ligament rupture and reconstruction:The significance of outcome score prediction

BACKGROUND Numerous anterior cruciate ligament(ACL) clinical outcome measures exist.However,the result of one score does not equate to the findings of another even when evaluating the same patient group.AIM To investigate if statistically derived formulae can be used to predict the outcome of one knee scoring system when the result of another is known in patients with ACL rupture before and after reconstruction.METHODS Fifty patients with ACL rupture were evaluated using nine clinical outcome measures.These included Tegner Activity Score,Lysholm Knee Score,Cincinnati Knee Score,International Knee Documentation Committee(IKDC) Objective Knee Score,Tapper and Hoover Meniscal Grading Score,IKDC Subjective Knee Score,Knee Outcome Survey-Activities of Daily Living Scale(KOS-ADLS),Short Form-12 Item Health Survey and Knee Injury and Osteoarthritis Outcome Score.Thirtyfour patients underwent an ACL reconstruction and were reassessed post-operatively.RESULTS The mean total of each of the nine outcome scores appreciably differed from each other.Significant correlations and regressions were found between most of the outcome scores and were stronger post-operatively.The strongest correlation was found between Cincinnati and KOS-ADLS (r=0.91,P<0.001).The strongest regression formula was also found between Cincinnati and KOS-ADLS (R~2=0.84,P<0.001).CONCLUSION The formulae produced from this study can be used to predict the outcome of one knee score when the results of the other are known.These formulae could facilitate the conduct of systematic reviews and meta-analysis in studies relating to ACL injuries by allowing the pooling of substantially more data.

Current and future of anterior cruciate ligament reconstruction techniques

In recent years,anterior cruciate ligament(ACL)reconstruction has generally yielded favorable outcomes.However,ACL reconstruction has not provided satisfactory results in terms of the rate of returning to sports and prevention of osteoarthritis(OA)progression.In this paper,we outline current techniques for ACL reconstruction such as graft materials,double-bundle or single-bundle reconstruction,femoral tunnel drilling,all-inside technique,graft fixation,preservation of remnant,anterolateral ligament reconstruction,ACL repair,revision surgery,treatment for ACL injury with OA and problems,and discuss expected future trends.To enable many more orthopedic surgeons to achieve excellent ACL reconstruction outcomes with less invasive surgery,further studies aimed at improving surgical techniques are warranted.Further development of biological augmentation and robotic surgery technologies for ACL reconstruction is also required.

Five Strand Hamstring Tendon Autograft for Anterior Cruciate Ligament Reconstruction Provides No Benefit over the Gold Standard Four Strand Repair for Anterior Stability of the Knee: A Prospective Cohort Study

The Four-Strand Hamstring Tendon Autograft has been long established as the gold standard for surgical reconstruction of the Anterior Cruciate Ligament. Some studies have suggested wider grafts, such as a Five-Strand hamstring graft, may provide greater strength and a larger scaffold for incorporation of the graft into the bone tunnels, leading to greater postoperative anterior stability of the knee. 28 (n = 18 Four-Strand and n = 10 Five-Strand) patients with planned ACL reconstructive surgery by a single surgeon were recruited for this study. The KT-1000 Arthrometer (MED metric, CA, USA) was used to quantify AP translation in the subjects’ knees before (T0) and after surgery at 6 (T1) and 12 (T2) weeks. At 12 weeks there was significantly higher (p = 0.01) mean anterior laxity on Maximum Manual Test in the Five- Strand group (9.1 ± 1.7 mm) than the Four Strand Group (6.9 ± 2.3 mm). Further, there were significantly higher mean side-to-side differences (p = 0.01) on Maximum Manual Test in the Five-Strand cohort (5.1 ± 3.5 mm) compared to the Four-Strand cohort (1.9 ± 2.2 mm). A significantly larger positive mean change in anterior laxity (p = 0.02) from 6 - 12 weeks was evident in the Five-Strand group (1.4 ± 0.9) than the Four-Strand group (-0.3 ± 1.9 mm). No significant correlations were seen between graft widths and measures of anterior stability on KT-1000. This study illustrated that there was no benefit to using a Five-Strand Hamstring Tendon Autograft when compared to the gold standard Four-Strand Repair specifically with regards to anterior stability of the knee.

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

Degradability of absorbable sutures in tendon grafts following anterior cruciate ligament reconstruction

Objective To observe the degradability of absorbable sutures in tendon grafts and the histology of tendon healing in a rabbit model.Methods Semitendinosus tendons were harvested from 15 healthy adult New Zealand rabbits in this study.