Background:
The tendon graft used in anterior cruciate ligament reconstruction (ACLR) undergoes “ligamentization” after implantation, and the reported length of this process varies from 6 to 48 ...months. Some grafts have ruptured at subsequent follow-up evaluations. Although the progress of graft ligamentization can be followed with postoperative magnetic resonance imaging (MRI) for reassessment, it is not known whether a delay in ligamentization (as reflected by a higher signal of the graft) is associated with an increased chance of subsequent graft rupture.
Hypothesis:
Signal intensity of the graft on reassessment MRI (signal-noise quotient SNQ) would be associated with the incidence of future graft rupture at subsequent follow-up.
Study Design:
Case-control study; Level of evidence, 3.
Methods:
A total of 565 ACLRs with intact graft on first-time reassessment MRI after surgery were followed for a mean period of 67 months. The rates of 1-year and 2-year follow-up were 99.5% and 84.5%, respectively. The signal intensity of the intact graft on the first-time reassessment MRI was evaluated (1) quantitatively by the SNQ and (2) qualitatively with the modified Ahn classification. Among the 565 ACLRs, 23 additional graft ruptures developed during a time interval of 7 months to 9 years after the surgery.
Results:
Higher SNQ was associated with increased chance of subsequent graft rupture (SNQ 7.3 ± 6 for subsequent graft rupture vs 4.4 ± 4 for grafts without subsequent rupture; P = .004, Mann-Whitney U test). The other important confounders that were associated with increased chance of graft rupture were younger age at the time of ACLR (P < .001) and longer follow-up time (P = .002). Multiple linear regression showed that all 3 factors (higher SNQ, younger age, and longer follow-up) were independent predictors of graft rupture (SNQ, P = .03; age, P < .001; follow-up, P = .012). When the reassessment MRI was performed in the second year after ACLR, the odds ratio of future graft rupture of a heterogeneous hyperintense graft when compared with a homogeneous hypointense graft was 12.1 (95% CI = 2.8 to 52.6) P < .001, Fisher exact test).
Conclusion:
Higher signal intensity of the intact graft on reassessment MRI (higher SNQ and heterogeneous hyperintense graft) was associated with increased chance of subsequent graft rupture.
Purpose
A debilitating complication following anterior cruciate ligament reconstruction is a secondary meniscus tear. Currently, the literature is mixed regarding the risk factors associated with the ...incidence of secondary meniscus tears. The aim of this study was to investigate risk factors associated with meniscus tears following an isolated primary anterior cruciate ligament reconstruction. ACL graft failure was hypothesized to be the strongest risk factor for secondary meniscal injury occurrence.
Methods
A retrospective cohort analysis was performed using the PearlDiver Database. Patients with a primary anterior cruciate ligament reconstruction were identified in the database. Patients with concomitant knee ligament injury or meniscus injury present at the time the index procedure were excluded. Patients were grouped to those who had a secondary meniscus tear within 2 years following anterior cruciate ligament reconstruction and those who did not. Univariate analysis and multivariable regression analysis was conducted to identify significant risk factors for a secondary meniscus tear.
Results
There were 25,622 patients meeting criteria for inclusion in this study. Within 2 years from the primary anterior cruciate ligament reconstruction, there were 1,781 patients (7.0%) that experienced a meniscus tear. Graft failure had the highest odds of having a postoperative meniscus tear within 2 years (OR: 4.1; CI 3.5–4.8;
p
< 0.002). Additional significant risk factors included tobacco use (OR: 2.0; CI 1.0–3.1;
p
< 0.001), increased Charlson Comorbidity Index (OR: 1.2; CI 1.1–1.4), male gender (OR: 1.1; CI 1.1–1.2;
p
< 0.001), obesity (OR: 1.1; CI 1.1–1.2;
p
< 0.001), delayed surgery (OR:1.1; CI 1.1–1.2;
p
< 0.002), and patients age 30 and older (OR: 1.0; CI 1.0–1.0;
p
< 0.001).
Conclusions
This study found that anterior cruciate ligament graft failure is the strongest predictor of post-operative meniscus tears. Other risk factors, including tobacco use, increased CCI, male gender, obesity, delayed surgery, and age 30 and older, were established, with several being modifiable. Therefore, targeted preoperative optimization of modifiable risk factors and postoperative protocols may reduce the risk of secondary meniscus tears.
Level of evidence
Level III, prognostic trial.
Background:
Given the unsatisfactory results and reported drawbacks of anterior cruciate ligament (ACL) reconstruction, such as donor site morbidity and the limited choice of grafts in revision ...surgery, new regenerative approaches based on tissue-engineering strategies are currently under investigation.
Purposes:
To determine (1) if a novel silk fiber–based ACL scaffold is able to initiate osteointegration in the femoral and tibial bone tunnels under in vivo conditions and (2) if the osteointegration process will be improved by intraoperatively seeding the scaffolds with the autologous stromal vascular fraction, an adipose-derived, stem cell–rich isolate from knee fat pads.
Study Design:
Controlled laboratory study.
Methods:
A total of 33 sheep underwent ACL resection and were then randomly assigned to 2 experimental groups: ACL reconstruction with a scaffold alone and ACL reconstruction with a cell-seeded scaffold. Half of the sheep in each group were randomly chosen and euthanized 6 months after surgery and the other half at 12 months. To analyze the integration of the silk-based scaffold in the femoral and tibial bone tunnels, hard tissue histology and micro–computed tomography measurements were performed.
Results:
Hard tissue histological workup showed that in all treatment groups, with or without the application of the autologous stromal vascular fraction, an interzone of collagen fibers had formed between bone and silk-based graft. This collagen-fiber continuity partly consisted of Sharpey fibers, comparable with tendon-bone healing known for autografts and allografts. Insertion sites were more broad based at 6 months and more concentrated on the slightly protruding, bony knoblike structures at 12 months. Histologically, no differences between the treatment groups were detectable. Analysis of micro–computed tomography measurements revealed a significantly higher tissue density for the cell-seeded scaffold group as compared with the scaffold-alone group in the tibial but not femoral bone tunnel after 12 months of implantation.
Conclusion:
The novel silk fiber–based scaffold for ACL regeneration demonstrated integration into the bone tunnels via the formation of a fibrous interzone similar to allografts and autografts. Histologically, additional cell seeding did not enhance osteointegration. No significant differences between 6 and 12 months could be detected. After 12 months, there was still a considerable amount of silk present, and a longer observation period is necessary to see if a true ligament-bone enthesis will be formed.
Clinical Relevance:
ACL regeneration with a silk fiber–based scaffold with and without additional cell seeding may provide an alternative treatment option to current techniques of surgical reconstruction.
Abstract Background The general opinion is that outcomes of open primary repair of the anterior cruciate ligament (ACL) in the historical literature were disappointing. Since good outcomes of primary ...repair of proximal tears have recently been reported, we aimed to assess the role of tear location on open primary repair outcomes in the historical literature. Methods All studies reporting outcomes of open primary ACL repair published between the inception of PubMed, Embase and Cochrane and 2000 were identified. Studies were included if tear location was reported. Outcome scores, return to sports, stability examinations, failures and patient satisfaction were collected and reviewed in the total study cohort and in a subgroup of studies treating only proximal tears. Spearman correlation analysis was performed between the percentage of proximal tears in the studies and all outcomes. Results Twenty-nine studies were included reporting outcomes of open primary in 1457 patients of which 72% had proximal and 23% midsubstance tears. Mean age was 30 years, 65% were males, and mean follow-up was 3.6 years. Good outcomes were noted in the total cohort, and excellent outcomes were noted following repair of proximal tears. Positive correlation was found between the percentage proximal tears in the studies and percentage satisfied patients (p = 0.010). Conclusion Tear location seems to have played a role on the outcomes of open primary ACL repair. Furthermore, outcomes of open primary repair in patients with proximal tears were excellent, which confirms there may be a potential role for primary repair as treatment for proximal ACL tears.
To benchmark current trends on anterior cruciate ligament reconstruction (ACLR) surgery.
The largest worldwide ACLR survey to date was performed during May 2020, targeted to reach representation of ...all continents. It was submitted electronically to all International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports surgeons (n = 3,026), asking those who perform ACLR to respond.
With a final sample size of 2,107, the overall response rate was 69.6%. Median years of practice as orthopaedic surgeon was 15 (range 1–52) and 49.6% of all respondents were defined as high-volume surgeons (>50 ACLR annually). Hamstrings tendon autograft was the preferred graft for primary ACLR (80.3%) and the medial portal femoral drilling was the most frequently used technique (78.5%). Cortical buttons (82.7%) and bioabsorbable screws (62.7%) were the preferred fixation methods for hamstring tendon autograft ACLR in femur and tibia, respectively. Metallic screws (45.2%) were the preferred fixation methods for bone patellar tendon bone autograft in femur and tibia. Most of the respondents routinely used pre-tensioning techniques for their graft preparation (63.8%), but less than half of surgeons preferred antibiotic soaking of the grafts (45.3%). The preferred knee position for graft fixation was 10–30° of knee flexion and neutral rotation (57.0%). The addition of anterolateral augmentation (or extra-articular tenodesis) was infrequent in primary and isolated ACLR (10.0%), but a statistically significant raise was seen for revision surgeries (20.0%). Most used brace in the initial postoperative rehabilitation (54.9%) and the time to allow patients to fully resume sports was at an average of 8.9 ± 2.0 months. Treatment algorithm of paediatric ACL injuries exhibited a low consensus among the respondents.
This worldwide survey benchmarks the current trends in ACL reconstruction, achieving the largest participation of surgeons to date. Among the great variety of options available for ACL reconstructions, surgeons’ preferences showed some differences according to their location and expertise. Reporting trends in practice, and not only the evidence, is important to medical education and providing patients the safest care possible.
This is a Level V, expert opinion study.
Background
Double-bundle anterior cruciate ligament (ACL) reconstruction has demonstrated improved biomechanical properties and moderately better objective outcomes compared with single-bundle ...reconstructions. This could make an impact on the rerupture rate and reduce the risk of revisions in patients undergoing double-bundle ACL reconstruction compared with patients reconstructed with a traditional single-bundle technique. The National Knee Ligament Registers in Scandinavia provide information that can be used to evaluate the revision outcome after ACL reconstructions.
Questions/purposes
The purposes of the study were (1) to compare the risk of revision between double-bundle and single-bundle reconstructions, reconstructed with autologous hamstring tendon grafts; (2) to compare the risk of revision between double-bundle hamstring tendon and single-bundle bone-patellar tendon-bone autografts; and (3) to compare the hazard ratios for the same two research questions after Cox regression analysis was performed.
Methods
Data collection of primary ACL reconstructions from the National Knee Ligament Registers in Denmark, Norway, and Sweden from July 1, 2005, to December 31, 2014, was retrospectively analyzed. A total of 60,775 patients were included in the study; 994 patients were reconstructed with double-bundle hamstring tendon grafts, 51,991 with single-bundle hamstring tendon grafts, and 7790 with single-bundle bone-patellar tendon-bone grafts. The double-bundle ACL-reconstructed patients were compared with the two other groups. The risk of revision for each research question was detected by the risk ratio, hazard ratio, and the corresponding 95% confidence intervals. Kaplan-Meier analysis was used to estimate survival at 1, 2, and 5 years for the three different groups. Furthermore, a Cox proportional hazard regression model was applied and the hazard ratios were adjusted for country, age, sex, meniscal or chondral injury, and utilized fixation devices on the femoral and tibial sides.
Results
There were no differences in the crude risk of revision between the patients undergoing the double-bundle technique and the two other groups. A total of 3.7% patients were revised in the double-bundle group (37 of 994 patients) versus 3.8% in the single-bundle hamstring tendon group (1952 of 51,991; risk ratio, 1.01; 95% confidence interval (CI), 0.73–1.39; p = 0.96), and 2.8% of the patients were revised in the bone-patellar tendon-bone group (219 of the 7790 bone-patellar tendon-bone patients; risk ratio, 0.76; 95% CI, 0.54–1.06; p = 0.11). Cox regression analysis with adjustment for country, age, sex, menisci or cartilage injury, and utilized fixation device on the femoral and tibial sides, did not reveal any further difference in the risk of revision between the single-bundle hamstring tendon and double-bundle hamstring tendon groups (hazard ratio, 1.18; 95% CI, 0.85–1.62; p = 0.33), but the adjusted hazard ratio showed a lower risk of revision in the single-bundle bone-patellar tendon-bone group compared with the double-bundle group (hazard ratio, 0.62; 95% CI, 0.43–0.90; p = 0.01). Comparisons of the graft revision rates reported separately for each country revealed that double-bundle hamstring tendon reconstructions in Sweden had a lower hazard ratio compared with the single-bundle hamstring tendon reconstructions (hazard ratio, 1.00 versus 1.89; 95% CI, 1.09–3.29; p = 0.02). Survival at 5 years after index surgery was 96.0% for the double-bundle group, 95.4% for the single-bundle hamstring tendon group, and 97.0% for the single-bundle bone-patellar tendon-bone group.
Conclusions
Based on the data from all three national registers, the risk of revision was not influenced by the reconstruction technique in terms of using single- or double-bundle hamstring tendons, although national differences in survival existed. Using bone-patellar tendon-bone grafts lowered the risk of revision compared with double-bundle hamstring tendon grafts. These findings should be considered when deciding what reconstruction technique to use in ACL-deficient knees. Future studies identifying the reasons for graft rerupture in single- and double-bundle reconstructions would be of interest to understand the findings of the present study.
Level of Evidence
Level III, therapeutic study.
Systematic review.
Preoperative neuromuscular function is predictive for knee function and return to sports (RTS) after reconstruction of the anterior cruciate ligament (ACL). The aim of this review ...was to examine the potential benefits of prehabilitation on pre-/postoperative objective, self-reported and RTS-specific outcomes.
A systematic search was conducted within three databases. From the 1.071 studies screened, two randomized control trials (RCTs), two control trials (CTs) and two cohort studies (CS) met the inclusion criteria. Methodological quality rating adopted the PEDro- (RCT, CT) or Newcastle-Ottawa-Scale (CS).
Methodological quality of the included studies was moderate (PEDro score: 6.5 ± 1.7; range 4 to 9). Two studies reported higher increases of the maximal quadriceps torque from baseline to pre-reconstruction: one study in the limb symmetry index (LSI), and one in both legs of the prehabilitation group compared to the controls. At 12-weeks post-reconstruction, one study (from two) indicated that the prehabilitation group had a lesser post-operative decline in the single-leg-hop for distance LSI (clinically meaningful). Similar findings were found in terms of quadriceps strength LSI (one study). At both pre-reconstruction (three studies) and two-year post-surgery (two studies), the prehabilitation groups reached significantly higher self-reported knee function (clinically meaningful) than the controls. RTS tended to be faster (one study). At two years post-surgery, RTS rates (one study) were higher in the prehabilitation groups. The results provide evidence for the relevance of prehabilitation prior to ACL-reconstruction to improve neuromuscular and self-reported knee function as well as RTS. More high quality confirmatory RCTs are warranted.
PROSPERO 2017: CRD42017065491.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Objective
To determine the frequency of anterolateral ligament (ALL) injury in patients with acute anterior cruciate ligament (ACL) rupture and to analyse its associated injury patterns.
Methods
...Ninety patients with acute ACL rupture for which MRI was obtained within 8 weeks after the initial trauma were retrospectively identified. Two radiologists assessed the status of the ALL on MRI by consensus. The presence or absence of an ALL abnormality was compared with the existence of medial and lateral meniscal tears diagnosed during arthroscopy. Associated collateral ligament and osseous injuries were documented with MRI.
Results
Forty-one of 90 knees (46 %) demonstrated ALL abnormalities on MRI. Of 49 knees with intact ALL, 15 (31 %) had a torn lateral meniscus as compared to 25 torn lateral menisci in 41 knees (61 %) with abnormal ALL (
p
= 0.008). Collateral ligament (
p
≤ 0.05) and osseous injuries (
p
= 0.0037) were more frequent and severe in ALL-injured as compared with ALL-intact knees.
Conclusion
ALL injuries are fairly common in patients with acute ACL rupture and are statistically significantly associated with lateral meniscal, collateral ligament and osseous injuries.
Key Points
•
ALL injuries are fairly common in patients with acute ACL rupture.
•
ALL injuries are highly associated with lateral meniscal and osseous injuries.
•
MRI assessment of ACL-injured knees should include evaluation of the ALL.
Purpose
The aims of the study were (1) to evaluate the leg asymmetry assessed with ground reaction forces (GRFs) during unilateral and bilateral movements of different knee loads in anterior cruciate ...ligament (ACL) reconstructed patients and (2) to investigate differences in leg asymmetry depending on the International Knee Documentation Committee Subjective Form (IKDC) in order to identify potential compensation strategies.
Methods
The knee function of 50 ACL reconstructed (patella tendon) patients was examined at 31 ± 7 months after the surgery. GRFs were quantified during the sit-to-stand and stand-to-sit test, the step-up and step-down test, and the two- and one-leg vertical jump. Further, the IKDC score, the anterior–posterior knee laxity, and the concentric torque of the quadriceps and hamstring muscles were evaluated.
Results
Differences between the operated and non-operated leg were found in the knee laxity, the quadriceps torque, and GRFs. The patients with low IKDC scores demonstrated greater leg asymmetries in GRFs compared to the patients with high IKDC scores.
Conclusions
ACL reconstructed patients showed GRF asymmetries during unilateral and bilateral movements of different knee loads. Three compensation strategies were found in patients with low subjective knee function: (1) a reduced eccentric load, (2) an inter-limb compensation during bilateral movements, and (3) the avoidance of high vertical impact forces. These compensation strategies may be indicative of a protective adaptation to avoid excessive ACL strain. GRF measurements are practicable and efficient tools to identify individual compensation strategies during early rehabilitation.
Purpose
The present study aimed to investigate the three-dimensional topographic anatomy of the anterior cruciate ligament (ACL) bundle attachment in both ACL-rupture and ACL-intact patients who ...suffered a noncontact knee injury and identify potential differences.
Methods
Magnetic resonance images of 90 ACL-rupture knees and 90 matched ACL-intact knees, who suffered a noncontact knee injury, were used to create 3D ACL insertion models.
Results
In the ACL-rupture knees, the femoral origin of the anteromedial (AM) bundle was 24.5 ± 9.0% posterior and 45.5 ± 10.5% proximal to the flexion–extension axis (FEA), whereas the posterolateral (PL) bundle origin was 35.5 ± 12.5% posterior and 22.4 ± 10.3% distal to the FEA. In ACL-rupture knees, the tibial insertion of the AM-bundle was 34.3 ± 4.6% of the tibial plateau depth and 50.7 ± 3.5% of the tibial plateau width, whereas the PL-bundle insertion was 47.5 ± 4.1% of the tibial plateau depth and 56.9 ± 3.4% of the tibial plateau width. In ACL-intact knees, the origin of the AM-bundle was 17.5 ± 9.1% posterior (
p
< 0.01) and 42.3 ± 10.5% proximal (
n.s.
) to the FEA, whereas the PL-bundle origin was 32.1 ± 11.1% posterior (
n.s.
) and 16.3 ± 9.4% distal (
p
< 0.01) to the FEA. In ACL-intact knees, the insertion of the AM-bundle was 34.4 ± 6.6% of the tibial plateau depth (
n.s.
) and 48.1 ± 4.6% of the tibial plateau width (
n.s.
), whereas the PL-bundle insertion was 42.7 ± 5.4% of the tibial plateau depth (
p
< 0.01) and 57.1 ± 4.8% of the tibial plateau width (
n.s.
).
Conclusion
The current study revealed variations in the three-dimensional topographic anatomy of the native ACL between ACL-rupture and ACL-intact knees, which might help surgeons who perform anatomical double-bundle reconstruction surgery.
Level of evidence
III.
PDF
