scholarly journals Novel quantification of the regional strain distribution in the anterior cruciate ligament in response to simulated loading using micro-CT imaging

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Alexandra M. Blokker ◽  
Ryan Wood ◽  
Jaques C. Milner ◽  
David W. Holdsworth ◽  
Timothy A. Burkhart ◽  
...  

Abstract Purpose A large percentage of anterior cruciate ligament (ACL) surgical reconstructions experience sub-optimal outcomes within 2 years. A potential factor contributing to poor outcomes is an incomplete understanding of micro-level, regional ACL biomechanics. This research aimed to demonstrate a minimally invasive method that uses micro-CT imaging to quantify regional ACL strains under clinically relevant joint loading. Methods A pattern of 0.8 mm diameter zirconium dioxide beads were arthroscopically inserted into four regions of the ACL of four cadaveric knee specimens (mean [SD] age = 59 [9] years). A custom micro-CT compatible joint motion simulator then applied clinically relevant joint loading conditions, while an image was acquired at each condition. From the resulting images, strains within each region were calculated using the centroid coordinates of each tissue-embedded bead. Strain repeatability was assessed using the mean intra-specimen standard deviation across repeated load applications. A one-way repeated measures ANOVA (α = 0.05) was used to determine regional strain variations. Results The mean intra-specimen standard deviation across repeated load application was ±0.003 strain for all specimens. No statistically significant differences were found between tissue regions, although medium and large effect sizes (0.095–0.450) suggest that these differences may be clinically relevant. Conclusions The method presented here demonstrates a minimally invasive measurement of regional ACL strain under clinically relevant joint loads using micro-CT imaging. The strain measurements demonstrated excellent reliability across the five repeated load applications and suggest a non-homogenous distribution of strain through the ACL.

1986 ◽  
Vol 15 (3) ◽  
pp. 143-147 ◽  
Author(s):  
Michael E Brunet ◽  
Mark A Kester ◽  
Stephen D Cook ◽  
Ray J Haddad ◽  
Harry B Skinner

Digitized serial CAT scans of four non-embalmed cadaver knees were used in the computer-aided determination of the longitudinal (internal-external) centres of rotation. The mean and standard deviation of the centre of rotation locations were calculated both before and after sectioning the anterior cruciate ligament. Regardless of anterior cruciate ligament status, the mean location of the centre of rotation was on the tibial spine, slightly anterior to the origin of the posterior cruciate ligament. However, upon sectioning of the anterior cruciate ligament, the standard deviation of the centre of rotation location increased markedly in the latero-medial direction in three of the four legs tested.


2012 ◽  
Vol 18 (3) ◽  
pp. 111-115
Author(s):  
O.M. Russu ◽  
I. Gergely ◽  
Ancuța Zazgyva ◽  
I. Moldovan ◽  
T.S. Pop

Abstract Evaluating the early clinical results of anterior cruciate ligament reconstruction using hamstrings autograft, with interference screw on the tibial side (biocomposite interference screw, ConMed-Linvatec) and continuous closed loop fixation on the femoral side (XO-Button, ConMed-Linvatec), with and without intra-articular injection of autologous conditioned plasma (ACP). Our study included 21 patients with chronic anterior cruciate ligament (ACL) ruptures for whom we performed ACL reconstruction with a hamstrings autograft. The mean age was 34 years (range, 25 to 42), 16 patients were men and 5 were women. In 10 cases we performed an intraarticular infiltration of ACP at the end of the surgical intervention. Final evaluation was performed at the end of the 6th postoperative month using the Lysholm scoring system, Tegner activity scale and objective assessment with the RolimeterTM 50A. The Lysholm score was excellent in all cases at 6 months postoperatively, with a mean Lysholm score of 90 for patients without ACP and 91.09 for patients that received ACP; the mean Tegner activity score was also similar pre- and postoperatively for the two groups (from 3.5 and 3.63 for the group without ACP and the group with ACP to 5.6 and 5.72 respectively). Joint laxity measurement was similar for both groups. We found no graft ruptures. We found similar results after ACL reconstruction with and without intra-articular injection of PRP, but further studies are necessary to determine the exact role of these substances in speeding up the recovery process in these cases.


2004 ◽  
Vol 12 (8) ◽  
pp. 614-626 ◽  
Author(s):  
Danika L. Batiste ◽  
Alexandra Kirkley ◽  
Sheila Laverty ◽  
Lisa M.F. Thain ◽  
Alison R. Spouge ◽  
...  

2021 ◽  
pp. 036354652110273
Author(s):  
Joshua S. Everhart ◽  
Sercan Yalcin ◽  
Kurt P. Spindler

Background: Several long-term (≥20 years) follow-up studies after anterior cruciate ligament (ACL) reconstruction have been published in recent years, allowing for a systematic evaluation of outcomes. Purpose: To summarize outcomes at ≥20 years after ACL reconstruction and identify patient and surgical factors that affect these results. Study Design: Systematic review; Level of evidence, 4. Methods: Prospective studies of primary ACL reconstructions with hamstring or bone–patellar tendon—bone (BTB) autograft via an arthroscopic or a mini-open technique and with a mean follow-up of ≥20 years were identified. When possible, the mean scores for each outcome measure were calculated. Factors identified in individual studies as predictive of outcomes were described. Results: Five studies met the inclusion and exclusion criteria with a total of 2012 patients. The pooled mean follow-up for patient-reported outcome measures was 44.2% (range, 29.6%-92.7%) and in-person evaluation was 33.2% (range, 29.6%-48.9%). Four studies (n = 584) reported graft tears at a mean rate of 11.8% (range, 2%-18.5%) and 4 studies (n = 773) reported a contralateral ACL injury rate of 12.2% (range, 5.8%-30%). Repeat non-ACL arthroscopic surgery (4 studies; n = 177) to the ipsilateral knee occurred in 10.4% (range, 9.5%-18.3%) and knee arthroplasty (1 study; n = 217) in 5%. The pooled mean of the International Knee Documentation Committee subjective knee function (IKDC) score was 79.1 (SD, 21.8 [3 studies; n = 644]). In 2 studies (n?= 221), 57.5% of patients continued to participate in strenuous activities. The IKDC-objective score was normal or nearly normal in 82.3% (n = 496; 3 studies), with low rates of clinically significant residual laxity. Moderate-severe radiographic osteoarthritis (OA) (IKDC grade C or D) was present in 25.9% of patients (n = 605; 3 studies). Medial meniscectomy is associated with increased risk of radiographic OA. Radiographic OA severity is associated with worse patient-reported knee function, but the association with knee pain is unclear. Conclusion: Currently available prospective evidence for ACL reconstruction with hamstring or BTB autograft provides several insights into outcomes at 20 years. The rates of follow-up at 20 years range from 30% to 93%. IKDC-objective scores were normal or nearly normal in 82% and the mean IKDC-subjective score was 79 points.


2002 ◽  
Vol 30 (4) ◽  
pp. 537-540 ◽  
Author(s):  
Sharon L. Hame ◽  
Daniel A. Oakes ◽  
Keith L. Markolf

Background The anterior cruciate ligament has been shown to be particularly susceptible to injury during alpine skiing. Tibial torque is an important injury mechanism, especially when applied to a fully extended or fully flexed knee. Purpose We wanted to record the forces generated in the anterior cruciate ligament with application of tibial torque to cadaveric knees in different positions. Study Design Controlled laboratory study. Methods Thirty-seven fresh-frozen cadaveric knees were instrumented with a tibial load cell that measured resultant force in the anterior cruciate ligament while internal and external tibial torques were applied to the tibia at full extension, 90° of flexion, full flexion, and forced hyperflexion. Results At each knee flexion position, mean force generated by 10 N·m of internal tibial torque was significantly higher than the mean generated by 10 N·m of external tibial torque. Mean forces generated by tibial torque at 90° of flexion were relatively low. During flexion-extension without tibial torque applied mean forces were highest (193 N) when the knee was hyperflexed. Conclusions Application of internal tibial torque to a fully extended or fully flexed knee represents the most dangerous loading condition for injury from twisting falls during skiing. Clinical Relevance Understanding of the mechanisms of falls can be used to design better equipment and to better prevent or treat injury.


1998 ◽  
Vol 26 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Bernard R. Bach ◽  
Steven Tradonsky ◽  
John Bojchuk ◽  
Matthew E. Levy ◽  
Charles A. Bush-Joseph ◽  
...  

We retrospectively reviewed the results of 97 patients with anterior cruciate ligament reconstructions using an arthroscopically assisted two-incision technique without extraarticular augmentation at an intermediate followup of 5 to 9 years postoperatively. Evaluation included detailed history, physical examination, functional testing, KT-1000 arthrometer measurements, multiple scoring systems, and radiographs. The results were compared with those from a previous study that evaluated a smaller patient cohort using the identical surgical technique at a 2- to 4-year followup. The post-operative physical examination and KT-1000 arthrometer results were statistically improved when compared with preoperative findings. A negative pivot shift result was noted in 83% of patients, and a 1 result in 17% of patients. Seventy percent of patients had 3 mm difference on manual maximum side-to-side testing. Functional testing averaged less than 2% asymmetry for vertical jump, single-legged hop, or timed 6-meter hop. The Tegner activity level was significantly improved from prereconstruction ratings and similar to preinjury ratings. The mean Lysholm score was 87. The modified Hospital for Special Surgery scores resulted in good or excellent results in 82% of the patients (mean, 87 points). The mean Noyes sports function score was 89, and the reoperation rate for a symptomatic knee flexion contracture was 12%. Ninety-seven percent of patients indicated that they would undergo the procedure again. When compared with this same population at 2 to 4 years, we saw no deterioration in scoring scale results.


2016 ◽  
Vol 1 (s2) ◽  
pp. 23-26
Author(s):  
Octav Russu ◽  
Tiberiu Bățagă ◽  
Andrei-Marian Feier ◽  
Radu Prejbeanu ◽  
Radu Fleaca ◽  
...  

Abstract Introduction: Anterior cruciate ligament (ACL) rupture is one of the most common lesions in knee traumatology; therefore the number of ACL reconstructions is increasing worldwide. Usually, an anteromedial (AM) accessory portal is required in anatomical positioning of the femoral tunnel, which is not absolutely necessary in this technique. Aim: Assessment of all-inside ACL reconstruction preliminary clinical results with adjustable loops and buttons on both femoral and tibial surfaces. Method: Our prospective study included 28 subjects (19 male, 9 female) with chronic ACL ruptures. The mean age of the study population was 27.72 ± 8.23 years. In all cases ACL reconstruction was carried out with the use of quadrupled semitendinosus auto-grafts with adjustable loops and buttons on the femoral and tibial surfaces and anatomic placement of both tunnels, using an outside-in technique, with flipcutters (Arthrex®). Clinical and radiological evaluations were carried out before surgery and at 3 and 6 months postoperatively, with the Lysholm scoring system, the Tegner activity scale and anterior-posterior and latero-lateral X-rays. Anterior knee laxity was measured in 25° of flexion using a portable arthrometer (RolimeterTM, Aircast®) and maximum manual force. Results: During the final follow-up, the Lysholm score was good and excellent in 27 cases, with a mean Lysholm score of 95.55 ± 4.63; all results were classified as good. The mean preoperative Tegner activity score was 3.46 ± 1.71 (range: 1-7), and the post-operative mean score was 5.75 ± 2.24 (range: 2-10). We found no graft ruptures. Preoperative knee laxity measurements showed a mean displacement of 11.5 ± 3.1 mm and side-to-side differences of 5.6 ± 3.5 mm, while the postoperative measurements at the last follow-up were 6.3 ± 1.54 mm and 2.65 ± 1.86 mm, respectively. Conclusion: Short-term clinical outcomes of all-inside ACL restoration with anatomic placement femoral and tibial tunnels seem to recommend this surgical option, with good subjective and objective results. Additional research will have to prove the long-term success.


2020 ◽  
pp. 036354652092309
Author(s):  
Matthew Colatruglio ◽  
David C. Flanigan ◽  
Joseph Long ◽  
Alex C. DiBartola ◽  
Robert A. Magnussen

Background: Anterior cruciate ligament reconstruction (ACLR) is a common orthopaedic sports medicine procedure, but graft failure is not uncommon and often leads to revision ACLR. Revision surgery can be performed in a 1- or 2-stage fashion. Hypothesis: Graft failure risk, patient-reported outcomes, and anterior knee laxity are similar after 1- and 2-stage revision ACLR. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review of the literature was performed to evaluate patient outcomes after 1- versus 2-stage revision ACLR. A search was performed with the phrase “revision anterior cruciate ligament reconstruction” across Embase, PubMed, Scopus, and SportDiscus from the beginning of their archives through July 12, 2019. Results: Thirteen studies met inclusion criteria and included 524 patients: 319 patients who underwent 1-stage revision ACLR and 205 patients who underwent 2-stage revision ACLR. Two studies compared outcomes of 1- versus 2-stage revision ACLR; 4 studies reported outcomes after 2-stage revision ACLR; and the remaining 7 studies documented outcomes after 1-stage ACLR. The mean follow-up was 4.1 years. The 2 studies that compared 1- versus 2-stage ACLR reported no differences in functional, radiologic, or patient-reported outcomes or failure risk. Overall, 9 studies reported subjective International Knee Documentation Committee (IKDC) scores; 4 studies, Knee injury and Osteoarthritis Outcome Score values; 8 studies, Lysholm scores; and 7 studies, Tegner scores; 8 studies measured anterior laxity with a KT-1000 arthrometer. The mean weighted subjective IKDC score for all studies including this outcome at final follow-up was 66.6 for 1-stage revisions and 65.9 for 2-stage revisions. Conclusion: The available evidence comparing 1- versus 2-stage revision ACLR is retrospective and limited. The results of each approach are similar in appropriately selected patients.


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