scholarly journals On Measuring Implant Fixation Stability in ACL Reconstruction

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6632
Author(s):  
Emir Benca ◽  
Ivan Zderic ◽  
Jan Caspar ◽  
Kenneth van Knegsel ◽  
Lena Hirtler ◽  
...  

Numerous methods and devices are available for implant fixation in anterior cruciate ligament (ACL) reconstruction. Biomechanical data indicate high variability in fixation stability across different devices. This study aims to provide a better insight into measuring the structural characteristics and mechanical behavior of ACL implant fixations. Fourteen human tibial specimens with reconstructed ACLs were subjected to progressively increasing dynamic loading until failure. The motions of the tibia, the proximal and distal graft ends, as well as the testing frame and actuator, were continuously recorded via a motion tracking system. Significantly higher displacements of the machine actuator (1.0 mm at graft slippage onset, and 12.2 mm at ultimate load) were measured compared to the displacements of the proximal (0.8 and 4.3 mm, respectively) and distal graft (0.1 and 3.4 mm, respectively) ends. The displacements measured at different sites showed significant correlations. The provided data suggest significant and systematic inaccuracies in the stiffness and slippage of the fixation when using machine displacement, as commonly reported in the literature. The assessment of the distal graft displacement excludes the artifactual graft elongation, and most accurately reflects the graft slippage onset indicating clinical failure. Considering the high displacement at the ultimate load, the ultimate load could be used as a standardized variable to compare different fixation methods. However, the ultimate load alone is not sufficient to qualitatively describe fixation stability.

2020 ◽  
Vol 8 (4) ◽  
pp. 232596712091160
Author(s):  
Matteo Maria Tei ◽  
Giacomo Placella ◽  
Marta Sbaraglia ◽  
Roberto Tiribuzi ◽  
Anastasios Georgoulis ◽  
...  

Background: Heat necrosis due to motorized drilling during anterior cruciate ligament (ACL) reconstruction could be a factor in delayed healing at the bone–tendon graft interface. Hypothesis: The process of osteointegration could be enhanced using manual drilling. It reduces the invasiveness of mechanical-thermal stress normally caused by the traditional motorized drill bit. Study Design: Controlled laboratory study. Methods: ACL reconstruction using semitendinosus tendon autografts was performed in 28 skeletally mature female New Zealand white rabbits, which were randomly divided into 3 groups. In group A (n = 12), the tunnels were drilled using a motorized device; in group B (n = 12), the tunnels were drilled using a manual drill bit; and group C (n = 4) served as a control with sham surgical procedures. The healing process in the tunnels was assessed histologically at 2, 4, 8, and 12 weeks and graded according to the Tendon–Bone Tunnel Healing (TBTH) scoring system. In addition, another 25 rabbits were used for biomechanical testing. The structural properties of the femur–ACL graft–tibia complex, from animals sacrificed at 8 weeks postoperatively, were determined using uniaxial tests. Stiffness (N/mm) and ultimate load to failure (N) were determined from the resulting load-elongation curves. Results: The time course investigation showed that manual drilling (group B) had a higher TBTH score and improved mechanical behavior, reflecting better organized collagen fiber continuity at the bone–fibrous tissue interface, better integration between the graft and bone, and early mineralized chondrocyte-like tissue formation at all the time points analyzed with a maximum difference at 4 weeks (TBTH score: 5.4 [group A] vs 12.3 [group B]; P < .001). Stiffness (23.1 ± 8.2 vs 17.8 ± 6.3 N/mm, respectively) and ultimate load to failure (91.8 ± 60.4 vs 55.0 ± 18.0 N, respectively) were significantly enhanced in the specimens treated with manual drilling compared with motorized drilling ( P < .05 for both). Conclusion: The use of manual drilling during ACL reconstruction resulted in better tendon-to-bone healing during the crucial early weeks. Manual drilling was able to improve the biological and mechanical properties of bone–hamstring tendon graft healing and was able to restore postoperative graft function more quickly. Tunnel drilling results in bone loss and deficient tendon-bone healing, and heat necrosis after tunnel enlargement may cause mechanical stress, contributing to a delay in healing. Manual drilling preserved the bone stock inside the tunnel, reduced heat necrosis, and offered a better microenvironment for faster healing at the interface. Clinical Relevance: Based on study results, manual drilling could be used successfully in human ACL reconstruction, but further clinical studies are needed. A clinical alternative, called the original “all-inside” technique, has been developed for ACL reconstruction. In this technique, the femoral and tibial tunnels are manually drilled only halfway through the bone for graft fixation, reducing bone loss. Data from this study suggest that hamstring tendon–to–bone healing can be improved using a manual drilling technique to form femoral and tibial tunnels.


Author(s):  
Willem M.P. Heijboer ◽  
Mathijs A.M. Suijkerbuijk ◽  
Belle L. van Meer ◽  
Eric W.P. Bakker ◽  
Duncan E. Meuffels

AbstractMultiple studies found hamstring tendon (HT) autograft diameter to be a risk factor for anterior cruciate ligament (ACL) reconstruction failure. This study aimed to determine which preoperative measurements are associated with HT autograft diameter in ACL reconstruction by directly comparing patient characteristics and cross-sectional area (CSA) measurement of the semitendinosus and gracilis tendon on magnetic resonance imaging (MRI). Fifty-three patients with a primary ACL reconstruction with a four-stranded HT autograft were included in this study. Preoperatively we recorded length, weight, thigh circumference, gender, age, preinjury Tegner activity score, and CSA of the semitendinosus and gracilis tendon on MRI. Total CSA on MRI, weight, height, gender, and thigh circumference were all significantly correlated with HT autograft diameter (p < 0.05). A multiple linear regression model with CSA measurement of the HTs on MRI, weight, and height showed the most explained variance of HT autograft diameter (adjusted R 2 = 44%). A regression equation was derived for an estimation of the expected intraoperative HT autograft diameter: 1.2508 + 0.0400 × total CSA (mm2) + 0.0100 × weight (kg) + 0.0296 × length (cm). The Bland and Altman analysis indicated a 95% limit of agreement of ± 1.14 mm and an error correlation of r = 0.47. Smaller CSA of the semitendinosus and gracilis tendon on MRI, shorter stature, lower weight, smaller thigh circumference, and female gender are associated with a smaller four-stranded HT autograft diameter in ACL reconstruction. Multiple linear regression analysis indicated that the combination of MRI CSA measurement, weight, and height is the strongest predictor.


2021 ◽  
Vol 9 (2) ◽  
pp. 232596712098164
Author(s):  
Steven F. DeFroda ◽  
Devan D. Patel ◽  
John Milner ◽  
Daniel S. Yang ◽  
Brett D. Owens

Background: Anterior cruciate ligament (ACL) injury in National Basketball Association (NBA) players can have a significant impact on player longevity and performance. Current literature reports a high rate of return to play, but there are limited data on performance after ACL reconstruction (ACLR). Purpose/Hypothesis: To determine return to play and player performance in the first and second seasons after ACLR in NBA players. We hypothesized that players would return at a high rate. However, we also hypothesized that performance in the first season after ACLR would be worse as compared with the preinjury performance, with a return to baseline by postoperative year 2. Study Design: Case series; Level of evidence, 4. Methods: An online database of NBA athlete injuries between 2010 and 2019 was queried using the term ACL reconstruction. For the included players, the following data were recorded: name; age at injury; position; height, weight, and body mass index; handedness; NBA experience; dates of injury, surgery, and return; knee affected; and postoperative seasons played. Regular season statistics for 1 preinjury season and 2 postoperative seasons were compiled and included games started and played, minutes played, and player efficiency rating. Kaplan-Meier survivorship plots were computed for athlete return-to-play and retirement endpoints. Results: A total of 26 athletes underwent ACLR; of these, 84% (95% CI, 63.9%-95.5%) returned to play at a mean 372.5 days (95% CI, 323.5-421.5 days) after surgery. Career length after injury was a mean of 3.36 seasons (95% CI, 2.27-4.45 seasons). Factors that contributed to an increased probability of return to play included younger age at injury (odds ratio, 0.71 [95% CI, 0.47-0.92]; P = .0337) and fewer years of experience in the NBA before injury (odds ratio, 0.70 [95% CI, 0.45-0.93]; P = .0335). Postoperatively, athletes played a significantly lower percentage of total games in the first season (48.4%; P = .0004) and second season (62.1%; P = .0067) as compared with the preinjury season (78.5%). Player efficiency rating in the first season was 19.3% less than that in the preinjury season ( P = .0056). Performance in the second postoperative season was not significantly different versus preinjury. Conclusion: NBA players have a high rate of RTP after ACLR. However, it may take longer than a single season for elite NBA athletes to return to their full preinjury performance. Younger players and those with less NBA experience returned at higher rates.


2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0010
Author(s):  
Brett Heldt ◽  
Elsayed Attia ◽  
Raymond Guo ◽  
Indranil Kushare ◽  
Theodore Shybut

Background: Acute anterior cruciate ligament(ACL) rupture is associated with a significant incidence of concomitant meniscal and chondral injuries. However, to our knowledge, the incidence of these concomitant injuries in skeletally immature(SI) versus skeletally mature(SM) patients has not been directly compared. SI patients are a unique subset of ACL patients because surgical considerations are different, and subsequent re-tear rates are high. However, it is unclear if the rates and types of meniscal and chondral injuries differ. Purpose: The purpose of this study is to compare associated meniscal and chondral injury patterns between SI and SM patients under age 21, treated with ACL reconstruction for an acute ACL tear. We hypothesized that no significant differences would be seen. Methods: We performed a single-center retrospective review of primary ACL reconstructions performed from January 2012 to April 2020. Patients were stratified by skeletal maturity status based on a review of records and imaging. Demographic data was recorded, including age, sex, and BMI. Associated intra-articular meniscal injury, including laterality, location, configuration, and treatment were determined. Articular cartilage injury location, grade, and treatments were determined. Revision rates, non-ACL reoperation rates, and time to surgery were also compared between the two groups. Results: 785 SM and 208 SI patients met inclusion criteria. Mean BMI and mean age were significantly different between groups. Meniscal tear rates were significantly greater in SM versus SI patients in medial meniscus tears(P<.001), medial posterior horn tears(P=.001), medial longitudinal tears configuration(P=.007), lateral Radial configuration(P=.002), and lateral complex tears(P=.011). Medial repairs(P<.001) and lateral partial meniscectomies(P=.004) were more likely in the SM group. There was a significantly greater number of chondral injuries in the SM versus SI groups in the Lateral(p=.007) and medial compartments(P<.001). SM patients had a significantly increased number of outerbridge grade 1 and 2 in the Lateral(P<.001) and Medial Compartments(P=.013). ACL revisions(P=.019) and Non-ACL reoperations(P=.002) were significantly greater in the SI patients compared to SM. No other significant differences were noted. Conclusion: SM ACL injured patients have a significantly higher rate of medial meniscus tears and medial longitudinal configurations treated with repair, and a significantly higher rate of radial and/or complex lateral meniscus tears treated with partial meniscectomy compared to the SI group. We also found a significantly higher rate of both medial and lateral compartment chondral injuries, mainly grades 1 and 2, in SM compared to SI patients. Conversely, SI ACL reconstruction patients had higher revision and subsequent non-ACL surgery rates.


2021 ◽  
pp. 155633162199200
Author(s):  
Ravi Gupta ◽  
Anil Kapoor ◽  
Sourabh Khatri ◽  
Dinesh Sandal ◽  
Gladson David Masih

Background: Osteoarthritis (OA) in the anterior cruciate ligament (ACL)–deficient knee is seen in approximately 50% of affected patients. Possible causes include biochemical or biomechanical changes. Purpose: We sought to study the correlation between inflammatory cytokines and chondral damage in ACL-deficient knees. Methods: Seventy-six male patients who underwent ACL reconstruction were enrolled in a cross-sectional study. Synovial fluid was aspirated before surgery and analyzed for levels of the inflammatory cytokines tumor necrosis factor-α, interleukin-1 (IL-1), and interleukin-6 (IL-6). At the time of ACL reconstruction, the severity of chondral damage was documented as described by the Outerbridge classification. Results: Patients with grade 2 or higher chondral damage were observed to have elevated IL-6 levels when compared to patients who had no chondral damage. Interleukin-6 levels had no correlation with the duration of injury. Conclusion: Elevated levels of IL-6 in synovial fluid were associated with chondral damage in ACL-deficient knees. Further study is warranted to determine whether inflammatory cytokines contribute to the development of OA of the knee after ACL injury.


Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S209-S221
Author(s):  
Lu Han ◽  
Hechen Zhang ◽  
Zhongxia Xiang ◽  
Jinze Shang ◽  
Shabila Anjani ◽  
...  

BACKGROUND: The contrast between a bright computer screen and a dark ambient environment may influence comfort of the users, especially on their eyes. OBJECTIVE: The objective of this research is to identify the optimal desktop lighting for the comfortable use of the computer screen in a dark environment. METHODS: An experiment was designed where seven illumination setups were introduced for the users to perform their leisure tasks on a computer screen. Fifteen healthy subjects participated in the experiments. During each session, durations of the eye blinks, fixations and saccades of the user were recorded by an eye tracker. His/her neck and trunk movements were recorded by a motion tracking system as well. The comfort/discomfort questionnaire, localized postural discomfort questionnaire, NASA task load index and computer user questionnaire were used to record the overall comfort/discomfort, the local perceived physical discomfort, the cognitive workload, and general/eye health problems, respectively. RESULTS: Subjective and objective measurement results indicated that users felt more comfortable with high intensity warm lights using a computer screen. We also identified that the eye fixation durations, as well as the scores of two questions in the computer user questionnaire, have significant negative correlations with comfort. On the other side, the durations of blinks and the scores of three questions in the computer user questionnaire, were significantly correlated with discomfort. CONCLUSION: The warm (3000K) and high intensity (1500 lux) light reduced the visual and cognitive fatigue of the user and therefore improve the comfort of the user during the use of a computer screen.


Author(s):  
Tsuneari Takahashi ◽  
Tomohiro Saito ◽  
Tatsuya Kubo ◽  
Ko Hirata ◽  
Hideaki Sawamura ◽  
...  

AbstractFew studies have determined whether a femoral bone tunnel could be created behind the resident's ridge by using a transtibial (TT) technique-single bundle (SB)-anterior cruciate ligament (ACL) reconstruction. The aim of this study was to clarify (1) whether it is possible to create a femoral bone tunnel behind the resident's ridge by using the TT technique with SB ACL reconstruction, (2) to define the mean tibial and femoral tunnel angles during anatomic SB ACL reconstruction, and (3) to clarify the tibial tunnel inlet location when the femoral tunnel is created behind resident's ridge. Arthroscopic TT-SB ACL reconstruction was performed on 36 patients with ACL injuries. The point where 2.4-mm guide pin was inserted was confirmed, via anteromedial portal, to consider a location behind the resident's ridge. Then, an 8-mm diameter femoral tunnel with a 4.5-mm socket was created. Tunnel positions were evaluated by using three-dimensional computed tomography (3D-CT) 1 week postoperatively. Quadrant method and the resident's ridge on 3D-CT were evaluated to determine whether femoral tunnel position was anatomical. Radiological evaluations of tunnel positions yielded mean ( ±  standard deviation) X- and Y-axis values for the tunnel centers: femoral tunnel, 25.2% ± 5.1% and 41.6% ± 10.2%; tibial tunnel, 49.2% ± 3.5%, and 31.5% ± 7.7%. The bone tunnels were anatomically positioned in all cases. The femoral tunnel angle relative to femoral axis was 29.4 ± 5.5 degrees in the coronal view and 43.5 ± 8.0 degrees in the sagittal view. The tibial tunnel angle relative to tibial axis was 25.5 ± 5.3 degrees in the coronal view and 52.3 ± 4.6 degrees in the sagittal view. The created tibial bone tunnel inlet had an average distance of 13.4 ± 2.7 mm from the medial tibial joint line and 9.7 ± 1.7 mm medial from the axis of the tibia. Femoral bone tunnel could be created behind the resident's ridge with TT-SB ACL reconstruction. The tibial bone tunnel inlet averaged 13.4 mm from the medial tibial joint line and 9.7 mm medial from the tibia axis.


2020 ◽  
Vol 10 (1) ◽  
pp. 68
Author(s):  
Cristina Bobes Álvarez ◽  
Paloma Issa-Khozouz Santamaría ◽  
Rubén Fernández-Matías ◽  
Daniel Pecos-Martín ◽  
Alexander Achalandabaso-Ochoa ◽  
...  

Patients undergoing anterior cruciate ligament (ACL) reconstruction and patients suffering from knee osteoarthritis (KOA) have been shown to have quadriceps muscle weakness and/or atrophy in common. The physiological mechanisms of blood flow restriction (BFR) training could facilitate muscle hypertrophy. The purpose of this systematic review is to investigate the effects of BFR training on quadriceps cross-sectional area (CSA), pain perception, function and quality of life on these patients compared to a non-BFR training. A literature research was performed using Web of Science, PEDro, Scopus, MEDLINE, Dialnet, CINAHL and The Cochrane Library databases. The main inclusion criteria were that papers were English or Spanish language reports of randomized controlled trials involving patients with ACL reconstruction or suffering from KOA. The initial research identified 159 publications from all databases; 10 articles were finally included. The search was conducted from April to June 2020. Four of these studies found a significant improvement in strength. A significant increase in CSA was found in two studies. Pain significantly improved in four studies and only one study showed a significant improvement in functionality/quality of life. Low-load training with BFR may be an effective option treatment for increasing quadriceps strength and CSA, but more research is needed.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yuanjun Teng ◽  
Xiaohui Zhang ◽  
Lijun Da ◽  
Jie Hu ◽  
Hong Wang ◽  
...  

Abstract Background Interference screw is commonly used for graft fixation in anterior cruciate ligament (ACL) reconstruction. However, previous studies had reported that the insertion of interference screws significantly caused graft laceration. The purposes of this study were to (1) quantitatively evaluate the graft laceration from one single insertion of PEEK interference screws; and (2) determine whether different types of sutures reduced the graft laceration after one single insertion of interference screws in ACL reconstruction. Methods The in-vitro ACL reconstruction model was created using porcine tibias and bovine extensor digitorum tendons of bovine hind limbs. The ends of grafts were sutured using three different sutures, including the bioabsorbable, Ethibond and ultra-high molecular weight polyethylene (UHMWPE) sutures. Poly-ether-ether-ketone (PEEK) interference screws were used for tibial fixation. This study was divided into five groups (n = 10 in each group): the non-fixed group, the non-sutured group, the absorbable suture group, the Ethibond suture group and the UHMWPE suture group. Biomechanical tests were performed using the mode of pull-to-failure loading tests at 10 mm/min. Tensile stiffness (newtons per millimeter), energy absorbed to failure (in joules) and ultimate load (newtons) were recorded for analysis. Results All prepared tendons and bone specimens showed similar characteristics (length, weight, and pre-tension of the tendons, tibial bone mineral density) among all groups (P > 0.05). The biomechanical tests demonstrated that PEEK interference screws significantly caused the graft laceration (P < 0.05). However, all sutures (the bioabsorbable, Ethibond and UHMWPE sutures) did not reduce the graft laceration in ACL reconstruction (P > 0.05). Conclusions Our biomechanical study suggested that the ultimate failure load of grafts was reduced of approximately 25 % after one single insertion of a PEEK interference screw in ACL reconstruction. Suturing the ends of the grafts using different sutures (absorbable, Ethibond and UHMWPE sutures) did not decrease the graft laceration caused by interference screws.


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