The difference in clinical outcome of single-bundle anterior cruciate ligament reconstructions with and without remnant preservation: A meta-analysis

A study regarding the anterior cruciate ligament remnant: Differences in balance and postural control between remnant-preserving and remnant-non-preserving patients

INTRODUCTION

The anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. However, quantitative studies on evaluate the postural control influence resulted from the ACL remnant preservation or not are scarce. The aim of this study is to evaluate the postural control of patients submitted to ACL reconstruction with and without preservation of the injured remnant in pre and postoperative periods.

METHODS

Eighteen patients underwent ACL reconstruction and separated into 2 groups according to the preservation or not of the remnant: (I) submitted to ACL reconstruction with preservation of the remnant (10 patients); (II) submitted to ACL reconstruction without preservation of the remnant (8 patients). They were assessed using the Lysholm score and force plate, which evaluated the patient's postural stability for remnant and non-remnant preservation in ACL reconstruction surgery.

RESULTS

Group I showed statistically significant subjective and objective improvements, both at 3 and 6 months. Additionally, improvement of the Lysholm test at 6 months in Group II was also statistically significant. Furthermore, the results of the Friedman test for the VCOP and VY variables of Group I, with support of the injured side in the force plate, showed a statistically significant difference both for pre and postoperative period at 3 months, compared to the 6-month postoperative period. The variables EAC and VX were statistically different for Group II, considering the preoperative period, 3 and 6 months postoperatively.

CONCLUSION

Preserving the ACL remnant in patients with ACL injuries has a positive impact on postural stability during recovery.

Remnant-Sparing Anterior Cruciate Ligament Reconstruction Results in Similar Clinical, Functional, and Quality-of-Life Outcomes to Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction

Purpose

To compare a large cohort of patients who underwent remnant-sparing anterior cruciate ligament reconstruction (rACLR) with a matched group of patients who underwent anatomic single-bundle anterior cruciate ligament reconstruction (ACLR) with respect to clinical laxity, patient-reported outcomes, and functional testing.

Methods

Patients who underwent rACLR between January 2010 and December 2015 were matched according to age, sex, body mass index, and graft type to patients who underwent ACLR. The primary outcome measure was the ACL Quality of Life (ACL-QOL) score at final follow-up of 24 months. Secondary outcomes included functional tests and clinical laxity measurements at 6, 12, and 24 months postoperatively. Concurrent intra-articular pathology at the time of surgery and postoperative complications were also recorded. Statistical analyses included the dependent t test and the Wilcoxon signed rank test.

Results

A total of 210 rACLR patients were successfully matched to a corresponding cohort of 210 ACLR patients. There were no statistically significant differences in ACL Quality of Life (ACL-QOL) or functional testing results between the groups; however, scores in both groups showed a steady and statistically significant improvement over time. A statistically significant difference was noted with respect to the Lachman test findings, favoring the rACLR cohort (Z = -2.79, P = .005); no between-group difference was seen for the pivot-shift test (Z = -0.36, P = .72). The rACLR group had a significantly lower rate of concurrent meniscal and chondral injury. There was no difference in complications between the groups (Z = -0.49, P = .63).

Conclusions

There was no difference in patient-reported or functional testing outcomes in patients undergoing remnant-sparing compared with anatomic single-bundle ACLR. There was, however, a significantly lower rate of positive Lachman test findings after rACLR. Furthermore, the rate of concurrent meniscal and chondral pathology was lower in the rACLR group.

Level of Evidence

Level III, retrospective cohort study.

Is remnant preservation in anterior cruciate ligament reconstruction superior to the standard technique? An overview of systematic reviews

BACKGROUND

Anterior cruciate ligament injury is a common knee joint injury. Anterior cruciate ligament reconstruction is a common surgical treatment to treat anterior cruciate ligament injury. It may have certain advantages to retain the ligament stump during the operation, but the results of systematic evaluation on whether to retain the ligament stump are different. The conclusion is still controversial, and the quality needs to be strictly evaluated.

OBJECTIVE

To evaluate the methodological quality, risk of bias, reporting quality and evidence quality of the systematic review of remnant preservation in anterior cruciate ligament reconstruction, and to provide reference for clinical work.

METHODS

We systematically searched the system evaluations in 8 electronic databases, the languages were limited to Chinese and English, and the time limit was from the establishment of the database to June 2023. Two reviewers independently screened literature and extracted data. The methodological quality, risk of bias, reporting quality and quality of evidence were evaluated by AMSTAR-2, ROBIS, PRISMA and GRADE tools.

RESULTS

A total of 14 systematic reviews were included. The evaluation of results showed that the methodological quality of the included systematic reviews was relatively low, of which 5 were low quality and 9 were critically low quality. A small number of systematic reviews were low risk of bias. The system evaluation reports are relatively complete, but the lack of program registration is a common problem. A total of 111 pieces of clinical evidence were extracted from the included 14 systematic reviews. The quality of evidence was generally low, with only 7 pieces of high-quality evidence, 45 pieces of medium-quality evidence, and the rest were low and very low-quality evidence. Among the reasons for relegation, imprecision is the most common, followed by inconsistency and indirectness. The existing evidence shows that patients after anterior cruciate ligament reconstruction with remnant preservation have certain advantages in knee joint function, joint stability and proprioception recovery, which may be a more effective surgical method. However, it may also increase the incidence of postoperative complications and adverse reactions.

CONCLUSION

Compared with Standard Technique, Remnant Preservation in Anterior Cruciate Ligament Reconstruction has more advantages in restoring joint function and stability and proprioception. But the potential risks should also be considered by surgeons. At present, the quality of evidence is generally low, and the reliability of the conclusion is insufficient. It still needs to be verified and further in-depth research is needed.

Risk Factors for Symptomatic Cyclops Lesion Formation after Anterior Cruciate Ligament Reconstruction

Objective  To evaluate the incidence of symptomatic cyclops lesions requiring surgical treatment after anterior cruciate ligament (ACL) reconstruction and to establish possible intraoperative risk factors related to it. Methods  Three hundred and eighty-nine patients aged between 18 and 50 years who underwent primary ACL reconstruction were retrospectively evaluated. Patients were divided into groups according to the presence or absence of symptomatic cyclops lesions, and their characteristics were compared. Patients with associated lesions that required additional surgical procedures (except anterolateral extra-articular procedures) were not included. The rate of symptomatic cyclops lesions was recorded and the following parameters were evaluated: age, gender, time from injury to surgery, graft type and diameter, femoral tunnel perforation technique, fixation type, presence of knee hyperextension, preservation of the ACL remnant, associated anterolateral extra-articular procedure, associated meniscal injury and participation in sports. Results  389 patients were evaluated and 26 (6.7%) patients developed cyclops. The patients with and without cyclops lesions did not differ in age, time from injury to surgery, graft type or diameter, surgical technique, femoral fixation method, presence of knee hyperextension, remnant preservation and associated meniscal injury. The group with cyclops lesion had a higher proportion of females (10 (38.4%) vs 68 (18.7%); OR = 2.7; p  = 0.015), higher proportion of extra-articular reconstruction (18 (11.8%) vs 8 (3.4%); OR = 3.8; p  = 0.001) and higher proportion of sports practice (23 (8.6%) vs 3 (2.5%); OR = 3.6; p  = 0.026). Conclusion  In our series, 6.7% of the patients required arthroscopic removal of cyclops lesions. Female gender, associated extra-articular reconstruction and sports practice were factors related to this lesion. Remnant preservation had no relationship with cyclops lesion formation.

Effects of Preserving Anatomically Positioned and Adequate Remnant ACL Tissue in Double-Bundle ACL Reconstruction

Background

The advantages of remnant tissue preservation in anterior cruciate ligament (ACL) reconstruction (ACLR) remain controversial.

Hypothesis

It was hypothesized that a large amount of remnant tissue, especially if anatomically positioned, would improve patient-reported outcomes and second-look graft appearance after preserved double-bundle ACLR (DB-ACLR).

Study Design

Cohort study; Level of evidence, 3.

Methods

This retrospective study included 89 consecutive patients who underwent unilateral remnant-preserving DB-ACLR using 2 hamstring tendon autografts. The authors categorized the arthroscopic findings into 3 groups according to the location and volume of the ACL remnant tissue in the femoral notch: (1) anatomical attachment (group AA; n = 34); (2) nonanatomical attachment (group NA; n = 33); and (3) no remnant (group NR; n = 22). Based on second-look arthroscopy, the reconstructed graft was graded as excellent, fair, or poor. Patient-reported outcomes were evaluated at 2 years after surgery using the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Japanese Anterior Cruciate Ligament Questionnaire-25 (JACL-25).

Results

The AA and NA groups had a significantly shorter time from injury to surgery compared with the NR group (P = .0165). Considering the second-look arthroscopic findings, the authors found a significant difference in synovial coverage of the grafts between the 3 groups (P = .0018). There were no significant differences in the overall KOOS and JACL-25 score among the 3 groups; however, the KOOS-Sport and Recreation and KOOS-Quality of Life subscale scores were significantly higher in the AA group compared with the NA and NR groups (P = .0014 and .0039, respectively). The JACL-25 score for middle- to high-speed flexion and extension was significantly better in the AA group versus the NR group (P = .0261).

Conclusion

This study showed that preserving anatomically positioned and adequate remnant tissue during DB-ACLR improved second-look graft appearance and KOOS-Sport and Recreation and KOOS-Quality of Life scores.

Comparative Study of Graft Healing in 2 Years after “Tension Suspension” Remnant-Preserving and Non-Remnant-Preserving Anatomical Reconstruction for Sherman Type II Anterior Cruciate Ligament Injury

Purpose: To evaluate the degree of graft healing after “tension suspension” reconstruction of “Sherman II” anterior cruciate ligament injuries versus non-remnant preserving anatomical reconstruction and to compare the clinical outcomes of the two procedures. Method: The clinical data of 64 patients were retrospectively included. There were 31 cases in the “tension suspension” remnant-preserving reconstruction group and 33 cases in the non-remnant-preserving anatomical reconstruction group. The International Knee Documentation Committee (IKDC) score, the Tegner score, and the Lysholm activity score were assessed preoperatively and at 6 months, 1 year, and 2 years postoperatively, respectively. The signal/noise quotient (SNQ) of the grafts was measured at 6 months, 1 year, and 2 years after surgery to quantitatively evaluate the maturity of the grafts after ACL reconstruction; the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the reconstructed ACL region of interest (ROI) were measured using DTI. Result: A total of 64 patients were included in the study. The mean SNQ values of the grafts in the 6 months, 1 year, and 2 years postoperative remnant-preserving reconstruction (RP) groups were lower than those in the non-remnant-preserving (NRP) reconstruction group, with a statistically significant difference (p < 0.05). At each postoperative follow-up, the SNQ values of the tibial and femoral sides of the RP group were lower than those of the NRP group; the SNQ values of the femoral side of the grafts in both groups were higher than those of the tibial side, and the differences were statistically significant (p < 0.05). At 6 months, 1 year, and 2 years postoperatively, the FA and ADC values of the grafts were lower in the RP group than in the NRP group, and the differences were statistically significant (p < 0.05); the IKDC score and Lysholm score of the RP group were higher than the NRP group, which was statistically significant (p < 0.05). Conclusion: For Sherman II ACL injury, the graft healing including ligamentization and revascularization at 2 years after the “tension suspension” remnant-preserving reconstruction was better than that of non-remnant-preserving anatomic reconstruction.

Occurrence Rate of Cyclops Lesion After Anatomic Double-Bundle ACL Reconstruction: Comparison Between Remnant Tissue Preservation and Resection Methods

Background

The occurrence rate of cyclops lesion after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction with remnant tissue preservation remains unclear.

Hypothesis

The study hypotheses were as follows: (1) the occurrence rate of cyclops lesion will be comparable between the remnant-preserving and remnant-resecting ACL reconstruction methods, and (2) there will be no significant differences in clinical outcomes between the remnant-preserving and remnant-resecting procedures.

Methods

This retrospective comparative study involved 177 patients who underwent unilateral anatomic double-bundle ACL reconstruction using hamstring tendon autografts from 2014 to 2018 at our hospital. According to the Crain classification of ACL remnant tissue, 98 patients with remnant types I, II, or III underwent the remnant-preserving procedure (group A), and the remaining 79 patients with remnant type IV underwent the remnant-resecting procedure (group B). All patients underwent second-look arthroscopy. Patients were evaluated according to arthroscopic and clinical results at postoperative 15.2 ± 8.4 months (mean ± SD). Statistical comparisons between groups were made using the paired Student t test, chi-square test, and Fisher exact test.

Study Design

Cohort study; Level of evidence, 3.

Results

At second-look arthroscopy, the incidence of cyclops lesions was significantly higher in group B than in group A (29.1% vs 13.3%; P = .0139). Cyclops lesions were divided into 4 locations: femoral side (type 1), midsubstance (type 2), tibial side (type 3), and anterior (type 4) of the ACL graft. The ratio of the tibial-side cyclops lesion (type 3) was significantly higher in group B than in group A (P = .0354). There were no significant differences in the clinical evaluation scores between the procedures. Side-to-side anterior laxity was significantly less in group A than in group B (0.7 vs 1.6 mm; P = .0035). Concerning postoperative laceration and synovium coverage of the grafts, group A was significantly better than group B (P < .0001).

Conclusion

In this cohort of patients undergoing double-bundle ACL reconstruction, resection of the ACL remnant was associated with a significantly higher rate of cyclops lesion formation when compared with preservation of the remnant.

Effects of remnant preservation in anterior cruciate ligament reconstruction: A systematic review and meta-analysis

Background

Compared with standard anterior cruciate ligament (ACL) reconstruction, it is controversial whether anterior cruciate ligament reconstruction (ACLR) with remnant preservation can lead to better clinical outcomes. We conducted a systematic study and meta-analysis to assess the differences in clinical efficacy between the two.

Method

We searched for clinical randomized controlled studies and cohort studies included in the Cochrane library, PubMed, and Embase from March 2012 to March 2022 in English. The included studies were ACLR with or without remant preservation, and the data were extracted and the quality of the included studies was assessed by two authors, respectively. Revman 5.4 was used for statistical analysis and conclusions were presented.

Result

Ten articles containing a total of 777 patients were finally included. There was no significant difference in postoperative Lachman test [OR = 1.66, 95%CI (0.79, 3.49), P = 0.18 > 0.05], Tegner score [SMD = −0.13, 95%CI (−0.47, 0.22), P = 0.46 > 0.05], synovial coverage rate by second-look arthroscopy [OR = 1.55, 95%CI (0.66, 3.65), P = 0.32 > 0.05], the rate of cyclops lesion [OR = 3.92, 95%CI (0.53, 29.29), P = 0.18 > 0.05], joint range of motion [SMD = 0.27, 95%CI (−0.13, 0.68), P = 0.19 > 0.05] and re-injury rate [OR = 0.57, 95%CI (0.18, 1.74), P = 0.32 > 0.05] between the two groups. There were statistically significant differences in postoperative Lysholm score [SMD = 0.98, 95% CI (0.32, 1.64), P = 0.004 < 0.05], International Knee Documantation Committee grade (IKDC grade) [OR = 2.19, 95%CI (1.03, 4.65), P = 0.04 < 0.05], Pivot shift test [OR = 1.71, 95%CI (1.06, 2.77), P = 0.03 < 0.05], KT1000/2000 arthrometer side-to-side difference [SMD = −0.22, 95%CI (−0.42, −0.03), P = 0.02 < 0.05], operation time [SMD = 11.69, 95%CI (8.85, 14.54), P = 0.00001 < 0.05] and degree of tibial tunnel enlargement [SMD = −0.66, 95%CI (−1.08, −0.23), P = 0.002 < 0.05].

Conclusion

This meta-analysis concluded that remnant preservation significantly had better results in terms of patient functional score (Lysholm, IKDC), knee stability (Pivot shift test, postoperative side-to-side anterior laxity) and tibial tunnel enlargement. In terms of complications (incidence of Cyclops lesions, range of motion, re-injury rate), no significant differences were seen between the two groups. Although many studies concluded that remnant preservation could bring better synovial coverage, this meta-analysis indicated that there is insufficient evidence to support it, possibly due to different remnant preservation procedures.The potential risks associated with longer operation times are also worth considering.

Differential regional perfusion of the human anterior cruciate ligament: quantitative magnetic resonance imaging assessment

Purpose

Surgical reconstruction is the current standard for ACL rupture treatment in active individuals. Recently, there is renewed interest in primary repair of proximal ACL tears. Despite this, ACL biology and healing potential are currently not well understood. Vascularity is paramount in ACL healing; however, previous ACL vascularity studies have been limited to qualitative histological and dissection-based techniques. The study objective was to use contrast-enhanced quantitative-MRI to compare relative perfusion of proximal, middle, and distal thirds of the in situ ACL. We hypothesized perfusion would be greatest in the proximal third.

Methods

Fourteen cadaveric knees were studied (8 females, 6 males), age 25–61 years. Superficial femoral, anterior tibial, and posterior tibial arteries were cannulated; without intraarticular dissection. Contrast-enhanced quantitative-MRI was performed using a previously established protocol. ACL regions corresponding to proximal, middle, and distal thirds were identified on sagittal-oblique pre-contrast images. Signal enhancement (normalized to tibial plateau cartilage) was quantified to represent regional perfusion as a percentage of total ACL perfusion. Comparative statistics were computed using repeated measures ANOVA, and pairwise comparisons performed using the Bonferroni method.

Results

Relative perfusion to proximal, middle, and distal ACL zones were 56.0% ±17.4%, 28.2% ±14.6%, and 15.8% ±16.3%, respectively (p = 0.002). Relative perfusion to the proximal third was significantly greater than middle (p = 0.007) and distal (p = 0.001). No statistically relevant difference in relative perfusion was found to middle and distal thirds (p = 0.281). Post-hoc subgroup analysis demonstrated greater proximal perfusion in males (66.9% ± 17.3%) than females (47.8% ± 13.0%), p = 0.036.

Conclusion

Using quantitative-MRI, in situ adult ACL demonstrated greatest relative perfusion to the proximal third, nearly 2 times greater than the middle third and 3 times greater than the distal third. Knowledge of differential ACL vascular supply is important for understanding pathogenesis of ACL injury and the process of biological healing following various forms of surgical treatment.

Remnant preserving ACL reconstruction with a functional remnant is related to improved laxity but not to improved clinical outcomes in comparison to a nonfunctional remnant

PURPOSE

The Anterior cruciate ligament (ACL) remnant has been pointed out as a ligamentization enhancer. Nonetheless, the remaining tissue can be functional if it still provides some stability or nonfunctional. This study intends to compare the clinical results and knee stability of functional vs. nonfunctional remnant preservation ACL reconstruction (ACLR).

METHODS

One hundred and seventy-five patients with ACL injuries were included and underwent remnant preservation ACLR. They were divided into two groups accordingly to remnant tissue functionality: functional (Group F) and nonfunctional (Group NF). Primary outcome was defined as patient reported outcomes measured with Lysholm, IKDC and Tegner continuous scales and improvements. Secondary outcomes comprised of Lachman test, anterior drawer test, pivot shift test, extension and flexion deficit, graft coverage by remnant preserved tissue and failure rate (persistent instability or new ACL lesion). Menisci lesions, cartilage lesions and time to surgery were also recorded for each group.

RESULTS

One hundred and forty-four patients were available at a mean of 30.2 ± 10.1 months: 69 Functional and 75 Nonfunctional. Lysholm, IKDC and Tegner functional outcomes demonstrated no difference between the groups, Functional compared to Nonfunctional: 88.4 ± 10.5 vs. 92.2 ± 4.9, n.s. and 83.2 ± 11.3 vs. 87 ± 5.3, n.s. and 6 (5-10) vs. 6 (5-9), n.s., respectively. Lysholm and IKDC functional outcomes improvements demonstrated differences between the groups: Functional compared to Nonfunctional (39.3 ± 9.4 vs. 42.3 ± 7.4, p = 0.014 and 37.7 ± 10 vs. 41.0 ± 6.6, p = 0.032); however, they were not clinically significant. Functional group showed more stability on physical examination pre- and post-operatively (p < 0.001, p < 0.001). There was no difference regarding extension deficit (n.s.); however, functional group had more flexion deficit (p = 0.02). Nonfunctional group had better graft coverage (p = 0.001). There was no difference regarding failure rate: 4% vs. 9%, (n.s.).

CONCLUSION

Both remnant preservation ACLR techniques were able to achieve satisfactory functional outcomes. A functional remnant was not related to improved functional outcomes in comparison to a nonfunctional remnant; however, it was related to less laxity pre and postoperatively and inferior graft coverage.

LEVEL OF EVIDENCE

II.

Effect of Remnant-Preserving Reconstruction of Acute Anterior Cruciate Ligament Injuries in a Rabbit Model: Histological and Biomechanical Analysis

Acute anterior cruciate ligament (ACL) is a key structure that stabilizes knee joints. The objective of this research is to investigate the influence of ligament remnants preserved on the tendon-bone healing following ACL reconstruction and to examine postoperative articular cartilage degeneration in rabbit as a model animal. Sixty New Zealand rabbits are randomly divided into an ACL reconstruction without remnant preservation group (Group A; n = 30) or ACL reconstruction with remnant preservation group (Group B; n = 30). The expression of HIF-1α, VEGF, and micro vessel density (MVD) in the transplanted tendon was detected by immunohistochemical staining at week 6 and 12 after the operation. The signal intensity of the transplanted tendon was observed by MRI scanning, and the width of the bone tunnel was measured by CT scanning at week 6 and 12 after the operation. The graft biomechanics was tested 12 weeks after the operation. The JNK and MMP-13 expression levels were compared to analyze the cartilage degeneration of the knee at week 12 after the operation. The experimental results were analyzed and showed that the remnant-preserving ACL reconstruction is beneficial for bone healing of the tendon in rabbits, but ACL reconstruction with or without ligament remnants preserved will not affect knee articular cartilage degeneration post-surgery.

Remnant preservation with tensioning can improve the clinical outcome after anterior cruciate ligament reconstruction

BACKGROUND

Many studies exist about remnant preservation in anterior cruciate ligament (ACL) reconstruction. However, concern remains for development of a cyclops lesion during remnant preservation. To prevent this, a tensioning method has been suggested. Current study evaluated the clinical and radiologic results of remnant preservation in ACL reconstruction with tensioning compared to classical ACL reconstruction.

METHODS

From January 2016 to June 2017, ACL reconstruction patients who underwent magnetic resonance imaging (MRI) 2 years postoperatively were enrolled. For comparison, all participants were divided in two groups: remnant preservation with tensioning (group R) and controls (group C). Clinically, Hospital for Special Surgery (HSS), International Knee Documentation Committee (IKDC), Lysholm scores, and incidence of symptomatic cyclops lesions were evaluated. Radiologically, signal-to-noise quotient (SNQ) and size of the synovium on MRI as well as anterior instability in Telos stress radiographs were evaluated.

RESULTS

A total of 64 patients were enrolled (42 in group R and 22 in group C). The IKDC score in group R (70) was better than that in group C (62; p < 0.05). One patient in group R had a cyclops lesion with clinical symptoms and arthroscopic excision was recommended. Radiologically, the SNQ, synovium area, and anterior instability on Telos radiography showed no difference between the two groups.

CONCLUSION

Remnant preservation with tensioning is a good option for ACL reconstruction without the development of a cyclops lesion.

Effect of Remnant Tissues on Outcomes of Anterior Cruciate Ligament Reconstruction at Follow-up Arthroscopy

BACKGROUND

Remnant-preserving anterior cruciate ligament reconstruction (ACLR) is sought to enhance vascularization and maturation of a graft and to produce positive clinical outcomes after reconstruction.

OBJECTIVE

The purpose of this study was to investigate an effect of remnant anterior cruciate ligament (ACL) tissues on outcomes of ACLR 1 year after reconstruction in younger populations.

DESIGN

Retrospective chart review.

SETTING

Inpatient orthopedic surgical and rehabilitation clinic.

SUBJECTS

The subjects were 644 patients who underwent primary ACLR.

INDEPENDENT VARIABLES

The independent variables were age, height, and body weight of the subjects, and the presence of remnant tissue.

MAIN OUTCOME MEASURES

The outcome measure was the number of subjects with secondary infra-articular injuries at a follow-up arthroscopy after ACLR. The odds ratio was calculated and compared between the remnant-preserving ACLR (ACLR-P) and remnant-resecting (ACLR-R) groups to investigate the effect of remnant tissues on postoperative outcomes.

RESULTS

A total of 416 cases met our inclusion criteria and were included in this study. There were 136 cases (49 males and 87 females) in the ACLR-P group with the mean age (±SD) of 17.86 ± 2.85 years. There were 280 cases (106 males and 174 females) in the ACLR-R group, and the mean age (±SD) was 18.13 ± 2.73 years. Of 136 cases in the ALCR-P group, 54 (39.7%) had abnormal arthroscopic findings that lead to a surgical intervention. Of 280 patients in the ACLR-R group, 128 (45.7%) had abnormal findings. Odds ratio was 0.78 [95% confidence interval (CI), 0.51-1.18; P = 0.24]. Four cases in the ACLR-P group and 8 in the ACLR-R group were diagnosed with ACL retear during follow-up arthroscopy. Odds ratio was 1.03 (95% CI, 0.30-3.48; P = 0.96).

CONCLUSIONS

The presence of ACL remnant tissues did not have a significant effect on outcomes 1 year after reconstruction. However, there was a trend that lower percentage of patients with remnant-preserving ALCR had abnormal arthroscopic findings that lead to a surgical treatment at follow-up arthroscopy 1 year after initial reconstruction. The presence of remnant tissues did not have a significant effect on retear rate.

Preservation of the Tibial Stump During Anterior Cruciate Ligament Reconstruction Surgery Did Not Increase the Rate of Surgery for Symptomatic Cyclops Lesions

Background

Preservation of the tibial stump during anterior cruciate ligament reconstruction (ACLR) is controversial. While proposed benefits include enhanced graft revascularization, improved proprioception, and decreased graft rupture rates, a potential complication is the development of a symptomatic cyclops lesion. It is therefore important to determine whether any benefits outweigh potential complications.

Purpose

To determine whether greater preservation of the tibial stump remnant would be associated with a decreased graft rupture rate without a concomitant increase in the rate of surgery for symptomatic cyclops lesions at 2 years after ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

A cohort of 658 patients in whom the amount of tibial stump preserved was classified as no stump (n = 228), <50% (n = 342), or >50% (n = 88) was followed up for 2 years, with graft ruptures and surgical treatment for cyclops lesions recorded. Contingency and Kaplan-Meier survival analyses were used to determine trends among the 3 remnant preservation groups in terms of graft rupture rates and surgery for cyclops lesions. Subgroup analysis was also conducted to examine sex-based differences.

Results

There was no significant association between graft rupture rates and remnant preservation. There was a significant trend for fewer operations for symptomatic cyclops lesions with greater remnant preservation when the entire cohort was analyzed (P = .04) and also when only female patients were analyzed (P = .04).

Conclusion

Although preservation of the tibial stump remnant was not associated with a reduced graft rupture rate, it was also not associated with increased rates of surgery for symptomatic cyclops lesions.

A Simple Method to Reduce the Incidence of Cyclops Lesion after Anterior Cruciate Ligament Reconstruction

The purpose of this study is to determine the influence of debridement in and around the bone tunnels on the prevalence of cyclops lesion (CL), after anterior cruciate ligament reconstruction (ACLR) with hamstring grafts. Our hypothesis was that bone tunnel debridement during ACLR would reduce the prevalence of CL. Methods for debridement in and around the bone tunnels after tunnel drilling were standardized and applied to 38 knees undergoing double-bundle ACLR between 2011 and 2014, Group A (debridement group). Group B (nondebridement group) included 56 knees in which bone tunnel debridement was not performed. Postoperative MRI was performed to evaluate the presence of CL and the following three criteria: (1) the intercondylar site of CL (grade 1-3), depending on its anterior extent along the femoral condyle; (2) posterior bowing of the ACL graft; and (3) the positional relationship between the frontmost fiber of ACL graft and Blumensaat's line. If CL caused loss of extension or pain or discomfort during knee extension, it was defined as symptomatic CL (SCL). CL was detected in 8 cases (21.1%) in Group A and 26 cases (46.4%) in Group B. The prevalence of CL was significantly lower in Group A than in Group B (p = 0.010), and the risk ratio of CL was 0.31 (95% confidence interval: 0.12-0.79). Furthermore, 10 patients in Group B had SCL, compared with none in Group A (p = 0.004). In Group A, the intercondylar site of CL was grade 1 in all cases, while in Group B, the CL grades were 1 (n = 17), 2 (n = 7), 3 (n = 2) (p = 0.008). There were no cases of posterior bowing of the ACL in Group A, but six cases in Group B (p = 0.023). Debridement in and around the bone tunnel is a simple and effective method of preventing CL and SCL after ACLR. The level of evidence for the study is 3.

Clinical Outcome of Remnant-Preserving and I.D.E.A.L. Femoral Tunnel Technique for Anterior Cruciate Ligament Reconstruction

Objective

To assess the clinical results of the remnant‐preserving and I.D.E.A.L. femoral tunnel technique in the arthroscopic treatment of anterior cruciate ligament (ACL) injuries.

Methods

This was a retrospective single‐center, single‐surgeon study reviewing data from November 2016 to March 2019. Based on our inclusion/exclusion criteria, a total of 31 patients (18 males, 13 females; mean age, 23.6 years) who underwent arthroscopic ACL reconstruction with the remnant preservation and I.D.E.A.L. femoral tunnel technique were recruited and had a minimum follow‐up of 12 months. Clinical data and status of knee stability were recorded. The International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity scale were collected both preoperatively and at a minimum of 1‐year follow‐up.

Results

Statistically significant differences were detected between the preoperative and postoperative values for Lachman test and pivot‐shift test (P < 0.01). The mean postoperative Lysholm score was 89.6 ± 9.4, whereas the mean preoperative Lysholm score was 47.3 ± 12.8 (P < 0.01). The mean Tegner activity score was significantly higher at postoperative evaluation than at preoperative evaluation (6.5 ± 2.1 vs 2.6 ± 1.8; P < 0.01). The mean IKDC score was significantly improved from 49.5 ± 10.6 preoperatively to 88.2 ± 10.7 postoperatively (P < 0.01). No case of infection was reported. No radiograph showed any joint space narrowing or degenerative change at the last postsurgical follow‐up.

Conclusion

The anatomical remnant‐preserving and I.D.E.A.L. femoral tunnel technique achieves a satisfactory clinical outcome and provides an effective option for the treatment of ACL injuries.

Return to Sports after ACL Reconstruction with Resection or Remnant-Preserving Technique

Objectives  To analyze the results of anterior cruciate ligament (ACL) reconstruction with remnant-preserving versus remnant-resecting technique, concerning the return to pre-lesion activity level.

Methods  The present retrospective cohort study has assessed adults > 18 years old who underwent ACL anatomical reconstruction between 2010 and 2014. The main outcomes assessed were: level of physical activity (4-point scale), sports participation rate, ACL rerupture defined as documented lesion requiring revision surgery and the numeric pain scale rate (NPSR).

Results  A total of 83 individuals were included in the study, with a mean age of 31.8 years old and follow-up mean time of 4.2 years after the surgery. A total of 34 patients underwent ACL reconstruction with remnant-preserving technique, and 49 without remnant preservation. No statistically significant difference was found between groups in all outcomes assessed: level of physical activity before the lesion and after the surgery, ACL rerupture rates and postoperative pain level. Subgroup analysis has shown a statistically significant decrease in the activity level in both groups. The most practiced sport was football; 72% of patients in the remnant group have resumed football activity versus 52.6% of the control group.

Conclusion  Based in these findings, the comparison between ACL reconstruction with remnant preserving technique and remnant resecting technique has shown no differences concerning the return to prelesion activity level.

The Forgotten Joint Score-12 in Anterior Cruciate Ligament injuries

PURPOSE

The Forgotten Joint Score (FJS-12) is a scoring system initially created to assess post arthroplasty outcomes. It has since been used to evaluate Anterior Cruciate Ligament surgery outcomes. Our study aims to evaluate the applicability and validity of the FJS-12 in post Anterior Cruciate Ligament reconstructed patients, and to assess correlation with established Patient Reported Outcome Measure Scores in the same population.

DESIGN

Case series, level 3 evidence.

METHODS

We conducted a cross sectional study across patients who had undergone Anterior Cruciate Ligament reconstruction and carried out the FJS-12 questionnaire by phone interview. Patients who had undergone primary Anterior Cruciate Ligament reconstruction were considered for the study.

RESULTS

The average Forgotten Joint Score-12 for all 82 patients was 71.4 (±22.9), which corresponded to a normal distribution. The average Lysholm and Tegner score at the 2-year post-operative visit was 93.5 ± 9.5 and 5.8 ± 1.8 respectively and the distribution was non-normal. We noticed a large ceiling effect of 42.7% in the Lysholm scores, but only 8.4% in FJS-12. There was a weak correlation with Lysholm and a positive correlation with Tegner.

CONCLUSIONS

Forgotten Joint Score-12 seems to be a promising patient reported outcome measure that can be used in evaluating post Anterior Cruciate Ligament reconstruction outcomes. It is more discerning than traditional scores and is easy to administer thus it can used in the clinical follow-up of patients. With the scores being normally distributed, it makes for a meaningful PROMS and would allow more accurate application of parametric statistical tests.

Preservation of the Tibial Remnant in Anterior Cruciate Ligament Reconstruction May Improve Postoperative Proprioceptive Function

The purpose of this study was to retrospectively compare clinical results, including proprioceptive function, after anterior cruciate ligament (ACL) reconstruction between 2 groups using techniques that preserve and eliminate the tibial remnant. Forty-eight patients who were followed for at least 24 months after ACL reconstruction with 4-strand hamstring tendon autografts were enrolled in this study. They were then divided into 2 groups: the remnant-preserving group (group A, 26 patients), in whom more than 7 mm of the remnant tibial stump (approximately 20% of the mean length of the ACL) was preserved; and the remnant-eliminating group (group B, 22 patients), in whom the tibial remnant was eliminated during ACL reconstruction. The average duration of follow-up was 25.5 months. At last follow-up, patients were evaluated using the International Knee Documentation Committee scale, Hospital for Special Surgery score, Lachman test, arthrometer, reproduction of passive positioning (RPP) test, threshold to detection of passive motion (TTDPM) test, one-leg hop test, and single-limb standing test. The clinical results between the 2 groups were statistically compared. Group A showed significantly better results on the RPP test at 15° (P=.040) and 30° (P=.010), one-leg hop test (P=.017), and single-limb standing test (P=.007) compared with group B. The other results showed no significant differences. The remnant-preserving technique in ACL reconstruction yields better proprioceptive and functional outcomes and may help achieve postoperative patient satisfaction. [Orthopedics. 2020;43(4):e231-e236.].

Anterior cruciate ligament reconstruction with remnant preservation: current concepts

Anterior cruciate ligament (ACL) tears are a common knee injury, and anatomic ACL reconstruction (ACLR) is now the standard of care to restore knee stability. Nevertheless, re-tear rates exceeding 5% are commonly reported, with an even higher percentage of patients unable to achieve preinjury knee function. As the torn ACL remnant contains elements (eg, cells, blood vessels and mechanoreceptors) essential to ACL function, it has been hypothesised that ACLR with remnant preservation may improve graft remodelling, in turn more quickly and completely restoring ACL structure and function. In this Current Concepts review, we summarise the present understanding of ACLR with remnant preservation, which includes selective bundle reconstruction of partial (one-bundle) ACL tears and single- and double-bundle ACLR with minimal to partial debridement of the torn ACL stump. Reported benefits of remnant preservation include accelerated graft revascularisation and remodelling, improved proprioception, decreased bone tunnel enlargement, individualised anatomic bone tunnel placement, improved objective knee stability and early mechanical support (with selective bundle reconstruction) to healing tissues. However, clinical studies of ACLR with remnant preservation are heterogeneous in the description of remnant characteristics and surgical technique. Presently, there is insufficient evidence to support the superiority of ACLR with remnant preservation over the standard technique. Future studies should better describe the ACL tear pattern, remnant volume, remnant quality and surgical technique. Progress made in understanding and applying remnant preservation may inform, and be reciprocally guided by, ongoing research on ACL repair. The goal of research on ACLR with remnant preservation is not only to achieve anatomic structural restoration of the ACL but also to facilitate biologic healing and regeneration to ensure a more robust and functional graft.

Anatomical Remnant-Preserving Double-Bundle ACL Reconstruction With a New Remnant Augmentation Technique

Anterior cruciate ligament (ACL) remnant preservation techniques have been recently introduced for covering the graft with remnant to improve the clinical results of ACL reconstruction. Several theoretical advantages exist for this technique; however, clinical results remain inconsistent and controversial. We have focused on the biomechanical function of the remnant and have been performing a new remnant-preserving reconstruction procedure that augments the graft with residual remnant. Preserving the structure and continuity of good-quality remnants may help maintain the early postoperative stress on the tendon graft, thereby providing a positive effect on remodeling. Although our concept is significantly different from previously reported remnant preservation techniques and has several pitfalls, the surgical technique that we outline in this report is simple and does not require specialized equipment. The procedure will also work more advantageously in preserving the residual mechanoreceptors in the remnant. We believe that this method can be a procedure with better results for patients with remnants that are in good condition.

Outcome Differences of Remnant- Preserving versus Non-Preserving Methods in Arthroscopic Anterior Cruciate Ligament Reconstruction: A Meta-analysis with Subgroup analysis

Purpose

To analyze differences in clinical outcomes of arthroscopic anterior cruciate ligament reconstruction between remnant-preserving and non-preserving methods.

Methods

International electronical databases PubMed, Embase, and the Cochrane central database from January 1966 to December 2017 were searched for randomized controlled trials (RCTs) and observational studies that compared differences of clinical outcomes of ACL reconstruction with and without remnant preservation. A meta-analysis of these studies was performed to compare clinical outcomes. Subgroup analyses were conducted to evaluate the role of methodological quality in primary meta-analysis estimates.

Results

Five RCTs and six observational studies were included in this meta-analysis and subgroup analysis. The remnant-preserving method in arthroscopic ACL reconstruction showed a statistically significant difference compared to the non-preserving method regarding arthrometric evaluation (side-to-side difference). Lachman test, Lysholm scores, and IKDC subjective scores showed statistically minor difference in meta-analysis, but showed no significant difference in subgroup analysis. Remained parameters including pivot shift test, IKDC grades, incidence of cyclops lesion showed no statistically differences in meta-analysis or subgroup analysis.

Conclusions

This meta-analysis with subgroup analysis showed that arthroscopic remnant-preserving ACL reconstruction provided statistically significant but limited clinical relevance in terms of arthrometric evaluation. Results of Lachman test, Lysholm scores, and IKDC subjective scores demonstrated statistically minor differences.

Is Remnant Preservation in Anterior Cruciate Ligament Reconstruction Superior to the Standard Technique? A Systematic Review and Meta-Analysis

Purpose

This is a systematic review and meta-analysis of current evidence that aims at comparing the clinical outcomes of remnant-preserving anterior cruciate ligament reconstruction (ACLR) and standard ACLR.

Methods

A systematic review of randomized controlled studies and cohort studies comparing remnant-preserving ACLR with standard ACLR with a minimum level of evidence of II was performed. Studies were included by strict inclusion and exclusion criteria. Extracted data were summarized as preoperative conditions, postoperative clinical outcomes, and postoperative complications. When feasible, meta-analysis was performed with RevMan5.3 software. Study methodological quality was evaluated with the modified Coleman methodology score (CMS).

Results

Eleven studies (n = 466 remnant-preserving and n = 536 standard) met the inclusion criteria. The mean modified CMS for all included studies was 85.8 (range: 77–92 on a 100-point scale). In total, 466 patients underwent remnant-preserving ACLR by 3 different procedures: standard ACLR plus tibial remnant tensioning (n = 283), selective-bundle augmentation (n = 49), and standard ACLR plus tibial remnant sparing (n = 134). Remnant-preserving ACLR provided a superior outcome of postoperative knee anterior stability (WMD = −0.42, 95% CI, −0.66, −0.17; P < 0.01) and Lysholm score (WMD = 2.01, 95% CI, 0.53 to 3.50; P < 0.01). There was no significant difference between the two groups with respect to second-look arthroscopy (OR = 1.38, 95% CI, 0.53, 3.62; P=0.51), complications (OR = 1.24 95% CI, 0.76, 2.02; P=0.39), International Knee Documentation Committee (IKDC) subject scores, IKDC grades, Lachman test, and pivot-shift test.

Summary/conclusion

Remnant-preserving ACLR promotes similar graft synovial coverage and revascularization to standard ACLR. Equivalent or superior postoperative knee stability and clinical scores were observed for remnant-preserving ACLR compared with standard ACLR. No significant difference in the total complication rate between the groups was evident.

Incidence and risk factors for cyclops syndrome after anterior cruciate ligament reconstruction: A systematic literature review

BACKGROUND

Cyclops syndrome after anterior cruciate ligament (ACL) reconstruction is due to a fibrous nodule that develops in the anterior part of the intercondylar notch and prevents full knee extension. The primary objective of this systematic literature review was to evaluate the incidence of symptomatic cyclops lesion after ACL reconstruction. The secondary objective was to identify risk factors for cyclops syndrome.

HYPOTHESIS

Cyclops syndrome is common after ACL reconstruction and has several risk factors reported in the literature.

METHODS

A systematic literature review was performed by searching the PubMed, Medline, CINAHL, Cochrane, and Embase databases with the key terms 'cyclops' and 'ACL reconstruction'. The data thus retrieved were evaluated independently by two investigators. All articles in English or French that reported the incidence and risk factors of cyclops syndrome after ACL reconstruction were included.

RESULTS

The search retrieved the titles and abstracts of 79 articles, of which 20 were selected to be read in full; among these, 10 were included in the study. The incidence of symptomatic cyclops lesion ranged from 1.9% to 10.9%. Identified risk factors were as follows: pre-operatively, knee inflammation and/or motion restriction at the time of ACL reconstruction; intra-operatively, narrow intercondylar notch and excessively anterior position of the tibial tunnel; and post-operatively, persistent hamstring muscle spasm.

DISCUSSION

Development of a cyclops lesion is common after ACL reconstruction, occurs early, and may require further surgery. The knowledge of the risk factors provided by this study may improve the ability to devise effective preventive measures.

LEVEL OF EVIDENCE

II, systematic literature review.

ACL Reconstruction Using Autologous Hamstrings Augmented With the Ligament Augmentation and Reconstruction System Provides Good Clinical Scores, High Levels of Satisfaction and Return to Sport, and a Low Retear Rate at 2 Years

Background:

There are a number of surgical methods for undertaking anterior cruciate ligament (ACL) reconstruction (ACLR), although relatively high rates of ipsilateral retears and contralateral tears exist, with only 65% of patients returning to their preinjury level of sport. ACLR techniques adopting synthetic augmentation have been proposed in an attempt to improve clinical outcomes and reduce reinjury rates.

Purpose:

To determine the efficacy of ACLR using autologous hamstrings augmented with the Ligament Augmentation and Reconstruction System (LARS).

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 65 patients were prospectively treated with arthroscopically assisted single-bundle ACLR using hamstrings augmented with the LARS, of whom 50 were available for 1- and 2-year reviews. Patient-reported outcome measures (PROMs), KT-1000 arthrometer testing, knee range of motion, peak isokinetic knee strength testing, and a battery of 4 hop tests were employed. Limb symmetry indices (LSIs) were calculated. Analysis of variance was used to evaluate differences over time and between limbs. Data on return to the preinjury level of sport, retears, and reoperations were collected.

Results:

High PROM scores were demonstrated at 1 and 2 years. Before the injury, 47 patients (94%) were actively participating in level 1 or 2 sports, with 38 (76%) and 43 (86%) patients having returned at 1 and 2 years, respectively. Normal (<3 mm; 90%) or nearly normal (3-5 mm; 10%) KT-1000 arthrometer side-to-side differences were observed at 2 years. Apart from knee flexion (P < .0001), extension (P = .001), and the 6-m timed hop (P = .039), there were no between-limb differences at 1 year, and there were no differences on any objective measures at 2 years (all P > .05). Mean LSIs across all measures were ≥90%. At 2 years, 84% to 90% of patients were ≥90% on the hop tests, with 72% and 76% of patients having ≥90% for extension and flexion strength, respectively. Two reoperations were undertaken for meniscal tears (7 and 8.5 months), 1 patient (2%) suffered a retear at 7 months, and 2 patients (3%) suffered a contralateral tear (8 and 12 months).

Conclusion:

This augmented ACLR technique demonstrated good clinical scores, a high rate of return to sport, and low rates of secondary ruptures and contralateral ACL tears at 2 years. Some caution should be noted in interpreting these results, as 15 of 65 patients (23%) were not included in the 2-year follow-up.

Isokinetic eccentric training is more effective than constant load eccentric training for quadriceps rehabilitation following anterior cruciate ligament reconstruction: a randomized controlled trial

OBJECTIVE

To compare the effects of conventional (constant load) eccentric training and isokinetic eccentric training on quadriceps muscle mass, strength and functional performance in recreational athletes following anterior cruciate ligament (ACL) reconstruction.

METHODS

Thirty recreational male athletes (25 years old) undergoing ACL reconstruction received a standard rehabilitation program. Volunteers were randomized to conventional group (CG; n = 15) or isokinetic group (IG; n = 15) to be engaged in a 6-week (2 sessions/week) quadriceps eccentric training program at the extensor chair or at the isokinetic dynamometer, respectively. Assessments of quadriceps muscle mass (through magnetic resonance imaging), strength (through isokinetic dynamometry) and self-aware functionality (through questionnaire) were performed before and after the training programs. Single leg hop test performance was assessed only at post-training evaluation.

RESULTS

IG had significantly higher improvements than CG (p < 0.05) for all muscle mass outcomes (+17-23% vs. +5-9%), as well as for isometric (+34% vs. +20%) and eccentric (+85% vs. +23%) peak torques. There was no between-group difference (p > 0.05) for concentric peak torque, Lysholm score, and single leg hop test.

CONCLUSION

Isokinetic eccentric training promotes greater responses than conventional eccentric training on quadriceps muscle mass and strength of recreational athletes following ACL reconstruction.

[Effectiveness of a novel remnant-preserving anterior cruciate ligament reconstruction with bidirectional barbed suture]

Objective

To investigate the feasibility and effectiveness of a novel remnant-preserving anterior cruciate ligament (ACL) reconstruction with bidirectional barbed suture.

Methods

Between February 2014 and January 2016, 96 patients (96 knees) with ACL injury who met the inclusion criteria were recruited and randomly divided into 2 groups ( n=48). All patients underwent ACL reconstruction with autologous tendon. The tibial remnant was fixed with PDS-Ⅱ suture (control group) and bidirectional barbed suture (trial group). There was no significant difference in age, gender, injury side, the interval from injury to operation, and preoperative knee stability (KT-1000 test), International Knee Documentation Committee (IKDC) score, and Lysholm score ( P>0.05). The knee stability (KT-1000 test), IKDC score, Lysholm score, proprioception, and Cyclops lesion after operation were recorded.

Results

All incisions healed by first intention in both groups. Forty-four patients in control group were followed up 26-47 months (mean, 36.6 months), and 45 patients in trial group were followed up 26-48 months (mean, 35.6 months). At last follow-up, the IKDC score, Lysholm score, and KT-1000 test were significantly improved when compared with preoperative ones in both groups ( P<0.05); but no significant difference was found between 2 groups ( P>0.05). There was no significant difference in proprioception between 2 groups at 1 and 2 years after operation, and between 1 year after operation and 2 years after operation ( P>0.05) in the same group. The incidences of Cyclops lesion at 6 months, 1 year and 2 years after operation were 0, 4.44% (2/45), and 4.44% (2/45) in trial group, and 13.6% (6/44), 13.6% (6/44), 20.5% (9/44) in control group, showing significant differences between 2 groups at 6 months and at 2 years after operation ( P=0.012; P=0.022) and no significant difference at 1 year after operation ( P=0.157).

Conclusion

The remnant-preserving ACL reconstruction with bidirectional barbed suture can decrease the incidence of Cyclops lesions. However, this technique can not improve the effectiveness in terms of the clinical function and stability compared with the traditional technique.

No clinical difference in 10-year outcomes between standard and minimal graft debridement techniques in patients undergoing anterior cruciate ligament reconstruction using autologous hamstrings: a randomized controlled trial

PURPOSE

Delayed ligamentization following anterior cruciate ligament reconstruction (ACLR) may result in reduced graft stiffness and strength, and an increased risk of secondary re-tear. Remnant sparing ACLR may accelerate ligamentization and proprioceptive function, theoretically reducing re-injury risk. This study sought to investigate 10-year graft failure rates and patient perceived knee functioning in those undergoing ACLR with remnant preservation (RP), versus remnant debridement (RD).

METHODS

A prospective RCT allocated 49 patients to ACLR with a hamstrings autograft together with a RD (n = 25) or RP (n = 24) procedure, of which 86% were clinically evaluated at 10 years (22 RD, 22 RP). A detailed chart review and patient phone consultation was undertaken with all patients at 10 years to evaluate the incidence (and timing) of subsequent re-tear and/or contralateral ACL tear, as well as other knee injuries/surgeries, the patient's ability to perform full work/sport duties and their perceived knee function using a numerical rating scale (NRS).

RESULTS

No significant differences existed between groups in descriptive variables. There were 2 graft ruptures (10.0%) in the RP group and 3 (13.6%) in the RD group, with an earlier mean time to graft failure in the RD group (RD 7.7 ± 4.5 months, RP 49.5 ± 17.7 months), albeit the size of this sub-sample was too small for statistical comparison. There was a significantly higher number of patients requiring ≥ 1 additional ipsilateral knee surgery in the RP group (RP = 10, RD = 4, p = 0.048). At 10 years, there were no significant group differences in the percentage of patients returning to unrestricted activity, with 16 (72.7%) and 15 (75.0%) patients in the RD and RP ACLR groups, respectively, unrestricted in work/sport duties. There were no significant group differences in the functional NRS ratings.

CONCLUSIONS

No long term clinical benefit of RP ACLR could be determined by this study with similar re-tear incidence and perceived knee function. A statistically higher number of re-operations were observed in RP ACLR patients and, while re-tears were observed later after RP versus RD ACLR, the study was underpowered to detect statistical significance.

LEVEL OF EVIDENCE

Level II (prospective randomized controlled trial).

Does Remnant Preservation Influence Tibial Tunnel Enlargement or Graft-to-Bone Integration After Double-Bundle Anterior Cruciate Ligament Reconstruction Using Hamstring Autografts and Suspensory Fixation? A Computed Tomography and Magnetic Resonance Imaging Evaluation

Background:

Remnant-preserving anterior cruciate ligament (ACL) reconstruction was introduced to improve clinical outcomes and biological healing. However, the influences of remnant preservation on tibial tunnel position and enlargement are still uncertain.

Purpose:

To evaluate whether remnant-preserving ACL reconstruction influences tibial tunnel position or enlargement and to examine the relationship between tunnel enlargement and graft-to-bone integration in the tibial tunnel.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A total of 91 knees with double-bundle ACL reconstructions were enrolled in this study. ACL reconstruction was performed without a remnant (<25% of the intra-articular portion of the graft) in 44 knees (nonremnant [NR] group) and with remnant preservation in the remaining 47 knees (remnant-preserving [RP] group). Tibial tunnel position and enlargement were assessed using computed tomography (CT). Comparisons between groups were performed. Furthermore, graft-to-bone integration in the tibial tunnel was evaluated using magnetic resonance imaging, and the relationship between tunnel enlargement and graft-to-bone integration at 1 year after ACL reconstruction was assessed.

Results:

A total of 48 knees (25 in NR group, 23 in RP group) were included; 19 and 24 knees in the NR and RP groups were excluded, respectively, because of graft reruptures and a lack of CT scans. There were no significant between-group differences in tibial tunnel position (P > .05). The degree of posterolateral tunnel enlargement in the axial plane was significantly higher in the RP group than that in the NR group (P = .007) 1 year after ACL reconstruction. The degree of anteromedial tunnel enlargement on axial CT was significantly smaller in knees with graft-to-bone integration than in those without integration (P = .002) 1 year after ACL reconstruction.

Conclusion:

ACL reconstruction with remnant preservation did not influence tibial tunnel position and did not decrease the degree or incidence of tibial tunnel enlargement. At 1 year postoperatively, tunnel enlargement did not affect graft-to-bone integration in the posterolateral tunnel, but graft-to-bone integration was delayed in the anteromedial tunnel.

Preservation of remnant with poor synovial coverage has no beneficial effect over remnant sacrifice in anterior cruciate ligament reconstruction

PURPOSE

The purpose of the study was to evaluate the influence of synovial coverage of the remnant on clinical outcomes and graft healing in anterior cruciate ligament (ACL) reconstruction.

METHODS

Seventy-five patients who underwent second-look arthroscopy after a single-bundle ACL reconstruction using autologous quadriceps tendon graft were included. The patients were divided into two groups according to whether the remnant was preserved (group P, n = 42) or sacrificed (group S, n = 33). Group P was further classified according to the degree of synovial coverage of the remnant on initial arthroscopic findings: group A (remnant fully covered with synovium, n = 15), group B (synovial coverage >50%, n = 15), and group C (coverage <50%, n = 12). Clinical outcomes including manual laxity tests, KT-2000 side-to-side difference, modified Lysholm score, Tegner activity score, and International Knee Documentation Committee score were evaluated pre-operatively and prior to the second-look arthroscopy. Graft tension, degrees of synovialization, and gross integrity were evaluated on second-look arthroscopic examination.

RESULTS

There were no statistical differences in manual laxity tests, KT-2000 side-to-side difference, and clinical scores between groups P and S. In second-look arthroscopic examination, graft tension showed no difference between the two groups, but gross integrity and synovialization were significantly higher in group P (P = 0.032 and P = 0.008, respectively). In subgroup analysis, only group A showed higher grade regarding gross integrity and synovialization in comparison with group S (P = 0.007 and P < 0.001, respectively).

CONCLUSIONS

Preservation of remnant in ACL reconstruction showed no superiority concerning knee stability and clinical outcomes over remnant sacrificing at post-operative 1-year second-look arthroscopy. Preservation of remnant with good synovial coverage had a positive effect on graft synovialization and maintenance of graft integrity, but this effect was not observed in cases of a remnant with poor synovial coverage. When deciding whether to preserve the remnant or not, the degree of synovial coverage should be considered.

LEVEL OF EVIDENCE

III.

Higher Gene Expression of Healing Factors in Anterior Cruciate Ligament Remnant in Acute Anterior Cruciate Ligament Tear

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction with remnant preservation has been described and related to potential advantages. Literature is lacking regarding gene expression of potential factors related to ligament healing in the ACL remnant and its relation to time from injury.

HYPOTHESIS

The mRNA expression of ligament healing factors in the ACL remnant would be higher in acute tears (<3 months from injury) than in intermediate (3-12 months) and chronic (>12 months) injuries.

STUDY DESIGN

Controlled laboratory study.

METHODS

Gene expression of 21 genes related to ligament healing factors was analyzed in 46 ACL remnants biopsied during surgical reconstruction with quantitative real-time polymerase chain reaction technique. Specimens were divided into 3 groups according to time from injury: acute (<3 months from injury; n = 19), intermediate (3-12 months; n = 12), and chronic (>12 months; n = 15). Histological and immunohistochemical evaluation was performed by analysis of hematoxylin and eosin, CD-34, and S-100 staining.

RESULTS

Expression of COL1A1, COL1A2, COL3A1, COL5A1, COL5A2, COL12A1, LOX, PLOD1, and TNC genes in ACL remnant was greater in acute compared with chronic injuries. COL1A1, COL5A1, COL12A1, and TNC genes were also expressed more in the acute group compared with the intermediate group. Furthermore, expression of the genes COL1A1 and COL5A2 was significantly higher in female than in male patients. No difference in the number of blood vessels and mechanoreceptors among groups was observed in the microscopic evaluation.

CONCLUSION

The present study demonstrates that expression of COL1A1, COL1A2, COL3A1, COL5A1, COL5A2, COL12A1, LOX, PLOD1, and TNC genes in ACL remnant is greater in acute (<3 months from injury) compared with chronic (>12 months) injuries. Furthermore, COL1A1, COL5A1, COL12A1, and TNC genes were expressed more in the acute group compared with the intermediate group (3-12 months from injury).

CLINICAL RELEVANCE

ACL reconstructions with remnant preservation should be performed in patients with acute injuries, as in these cases the ACL remnant may present the greatest healing potential.

Single-bundle versus double-bundle autologous anterior cruciate ligament reconstruction: a meta-analysis of randomized controlled trials at 5-year minimum follow-up

BACKGROUND

Both single-bundle (SB) and double-bundle (DB) techniques were widely used in anterior cruciate ligament (ACL) reconstruction recently. Nevertheless, up to now, no consensus has been reached on whether the DB technique was superior to the SB technique. Moreover, follow-up of the included studies in the published meta-analyses is mostly short term. Our study aims to compare the mid- to long-term outcome of SB and DB ACL reconstruction concerning knee stability, clinical function, graft failure rate, and osteoarthritis (OA) changes.

METHODS

This study followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The PubMed, Embase, and the Cochrane Library were searched from inception to October 2017. The study included only a randomized controlled trial (RCT) that compared SB and DB ACL reconstruction and that had a minimum of 5-year follow-up. The Cochrane Collaboration's risk of bias tool was used to assess the risk of bias for all included studies. Stata/SE 12.0 was used to perform a meta-analysis of the clinical outcome.

RESULTS

Five RCTs were included, with a total of 294 patients: 150 patients and 144 patients in the DB group and the SB group, respectively. Assessing knee stability, there was no statistical difference in side-to-side difference and negative rate of the pivot-shift test. Considering functional outcome, no significant difference was found in proportion with International Knee Documentation Committee (IKDC) grade A, IKDC score, Lysholm scores, and Tegner scores. As for graft failure rate and OA changes, no significant difference was found between the DB group and the SB group.

CONCLUSION

The DB technique was not superior to the SB technique in autologous ACL reconstruction regarding knee stability, clinical function, graft failure rate, and OA changes with a mid- to long-term follow-up.

Anteromedial versus transtibial technique in single-bundle autologous hamstring ACL reconstruction: a meta-analysis of prospective randomized controlled trials

Background

The aim of this study was to compare the clinical outcome and postoperative complication between single-bundle anterior cruciate ligament (ACL) reconstruction with an anteromedial (AM) technique and a transtibial (TT) technique.

Methods

The study includes clinical randomized controlled trials comparing the clinical outcomes of ACL reconstruction using the autologous hamstring tendon with an AM method and a TT method published up to September 2017 were retrieved from PubMed, Cochrane Library, and Embase databases. Relevant data were extracted and the Physiotherapy Evidence Database (PEDro) scale was used to assess the methodological quality. Stata/SE 12.0 was used to perform a meta-analysis of the clinical outcome.

Results

Five RCTs were included, with a total of 479 patients: 239 patients and 240 patients in the AM group and the TT group, respectively. Assessing postoperative stability, better results were found in the AM group for the negative rate of the Lachman test (P < 0.05), the negative rate of the pivot-shift test (P < 0.05) and the side-to-side difference (P < 0.05). Assessing postoperative functional outcome, the AM group yielded superior results in proportion with International Knee Documentation Committee (IKDC) grade A (P < 0.05) and the Lysholm scores (P < 0.05) but had a comparable IKDC score (P > 0.05). In terms of postoperative complication, no significant difference was found between the AM group and the TT group (P > 0.05).

Conclusions

The outcome of single-bundle ACL reconstruction with the AM technique is better than that with the TT technique in terms of postoperative stability and functional recovery of the knee.

Double-bundle anterior cruciate ligament reconstruction with and without remnant preservation - Comparison of early postoperative outcomes and complications

BACKGROUND

To compare the early postoperative outcomes and complications of double-bundle anterior cruciate ligament (ACL) reconstruction with and without remnant preservation.

METHODS

The study population comprised 125 consecutive knees that underwent double-bundle ACL reconstruction using hamstring autograft. Among the 125 knees, remnant preservation was indicated for 50 knees, while standard double-bundle reconstruction was performed in the remaining 75 knees. Postoperative evaluations included heel-height difference (HHD) at periodical follow-ups, number of knees requiring arthroscopic debridement due to problematic extension loss within six months, re-injury within one year, graft status upon second-look arthroscopy, and clinical examinations by Lysholm score and KT measurement at one year.

RESULTS

All patients could be followed up for a minimum of one year after surgery. When the results obtained from both groups were compared, HHD values were significantly larger in the preservation group at three and six months, and the rate of knees requiring arthroscopic debridement was also higher in this group (12% versus 4.0%). Graft status on second-look arthroscopy was considered to be good for 92% of the knees in the preservation group versus 59% in the non-preservation group. Re-injury rates within one year were 2.0% in the preservation group and 5.3% in the non-preservation group. No significant differences in clinical examinations were found between the groups at one year.

CONCLUSIONS

Remnant preservation in double-bundle hamstring autograft ACL reconstruction may enhance tissue healing; however, retention of the remnant with its full volume resulted in an increased incidence of postoperative problematic extension loss.

Arthroscopic Anterior Cruciate Ligament Femoral Tunnel Visualization for Button Fixation

Arthroscopic reconstruction of the anterior cruciate ligament (ACL) remains one of the most commonly performed procedures in orthopaedic surgery. We describe a technique to visualize the button being advanced through the femoral tunnel using an arthroscope placed in the anteromedial portal. Looking into the femoral tunnel in line with the sutures, this technique allows the surgeon to directly visualize the femoral button as it traverses the femoral tunnel and confirms that it is engaged over the femoral cortex. Certain complications can arise, however, with the use of a suspensory fixation with a button on the femoral cortex. This method can decrease operative time and complication rates.

Anterior cruciate ligament remnant and its values for preservation

Controversy surrounds the remnant-preserving anterior cruciate ligament surgery. Advantages of remnant preservation have been reported in regard to better healing and knee function, although no consensus has been reached. This review article discussed the value and meaning of anterior cruciate ligament remnant preservation in several sections such as effects on healing, remnant classification, biomechanical evaluation, relation to proprioception, animal studies, and clinical studies. We hope that this review will facilitate further discussion and investigation for better treatment of anterior cruciate ligament injuries. So far, the current reviews have not provided sufficient scientific evidence to support the value of preserving the remnant.