Remnant-preserving Anterior Cruciate Ligament Reconstruction Research Articles

A Technique for Hamstring Donor-Site Injection With Anesthetic Cocktail in Remnant-Preserving Anterior Cruciate Ligament Reconstruction

Arthroscopic anterior cruciate ligament reconstruction is a common procedure that requires effective postoperative pain management for successful rehabilitation. Opioids are traditionally used for pain relief, but their side effects decrease their widespread use. Local anesthesia techniques have gained interest as an alternative to opioids. This Technical Note discusses the use of an anesthetic cocktail for pain relief at the hamstring's donor site in anterior cruciate ligament reconstruction. This approach may enhance early rehabilitation and patient satisfaction.

The apex of the deep cartilage is a stable landmark to position the femoral tunnel during remnant-preserving anterior cruciate ligament reconstruction.

The aim of this retrospective cohort study was to investigate whether the apex of the deep cartilage (ADC) could help surgeons position the femoral tunnel accurately in remnant-preserving anterior cruciate ligament (ACL) reconstruction (ACLR). In the current retrospective cohort study, a total of 134 patients who underwent ACLR between 2016 and 2020 were included. The femoral tunnel position was located using ADC as the landmark. The patients were divided into two groups: the remnant-preserving group (RP group, n = 68) underwent remnant-preserving ACLR, and the nonremnant group (NRP group, n = 66) underwent traditional ACLR with remnant removal. Postoperatively, the femoral tunnel position was evaluated on 3D-CT. The length from the ADC to the shallow cartilage margin (L) and to the centre of the femoral tunnel (l) and the length from the centre of the femoral tunnel to a low cartilage ratio in the direction from high to low (H) were measured. The l/L values of the RP and NRP groups were both 0.4 ± 0.1 after rounding (n.s.), and the H values were 9.3 ± 1.6mm and 9.3 ± 1.7mm, respectively (n.s.). There was no significant difference in l/L or H between the two groups. The estimation plot also showed high consistency of H and l/L of the two groups. The inter- and intraobserver reliability of I, L, l/L, and H were almost perfect. The apex of the deep cartilage is a good landmark for positioning the femoral tunnel in remnant-preserving ACL reconstruction. Level III.

The effects of remnant-preserving anterior cruciate ligament reconstruction on proprioception: A prospective comparative study.

The aim of this study was to investigate the effects of anterior cruciate ligament reconstruction performed by preserving remnant tissue on proprioception and to assess the effects it has on isokinetic quadriceps and hamstring muscle strength, as well as on range of motion and functional scores. A prospective study was conducted with 44 patients who underwent either anterior cruciate ligament reconstruction with remnant preservation (study group, n=22) or with remnant excision (control group, n=22) with the use of a 4-strand hamstring allograft. The mean follow-up time was 20.2 ± 1.4 months after surgery. Using an isokinetic dynamometer, proprioception was evaluated with passive joint position perception at 150, 450, and 600, and quadriceps femoris, and hamstring muscle strength were evaluated at speeds of 900, 1800, and 2400 per second. Range of motion was measured using a goniometer. Functional outcomes were assessed using International Knee Documentation Committee subjective knee evaluation score and Lysholm knee scoring questionnaires. It was only at 15° of knee flexion that there was a statistically significant difference in proprioception; the median of the difference in the amount of deviation from the target angle between the healthy knee and the operated side was 1.7 (range, 0.7-20.7) in those with remnant preserved, and 2.7 (range, 1-26) in those with remnant excised (P=.016). At 2400/s speed, the mean quadriceps femoris strength was 77.2 ± 24.3 Nm in those with remnant preserved and 67.6 ± 24.2 Nm in those with remnant excised. (P=.048) There was no difference between the 2 groups in terms of range of motion, International Knee Documentation Committee, and Lysholm knee scoring. (P > .05) Conclusion: The present study has demonstrated that better proprioception and higher quadriceps femoris muscle strength can be obtained by remnant-preserving anatomical single-bundle anterior cruciate ligament reconstruction using a hamstring autograft. Level II, Therapeutic study.

Graft impingement increases anterior cruciate ligament graft signal more than acute graft bending angle: magnetic resonance imaging-based study in outside-in anterior cruciate ligament reconstruction.

In this study, the relationship between patient-specific geometric factors and tunnel placement in graft impingement was identified by using magnetic resonance imaging (MRI) signal intensity of anterior cruciate ligament (ACL) grafts. Ninety-two patients, who were treated between 2014 and 2020, were included retrospectively. These patients underwent primary remnant-preserving outside-in ACL reconstruction (ACLR) and were followed up with postoperative MRI at least one year after surgery. Plain radiographs and computed tomography (CT) were used to analyze tibial and femoral tunnel positions. Postoperative MRI was performed, at 32.8 ± 17.5months after surgery, to evaluate the graft signal intensity, the ACL/posterior cruciate ligament (PCL) ratio (APR), ACL/muscle ratio (AMR), tunnel positions, and graft impingement. Clinical and stability outcomes were analyzed using the International Knee Documentation Committee (IKDC) subjective and objective scores, Lysholm scores, and side-to-side differences (SS-D). The mean APR and AMR of the proximal third of the grafts were significantly lower than those of the middle third of the grafts (p = 0.017 and p = 0.045, respectively). Multivariate regression analysis showed that there was a negative association between the mean APR and AMR of entire intra-articular ACL graft and the distance from the anterior end of the intercondylar roof to the center of the tibial tunnel in the sagittal plane (p < 0.001 and p < 0.001, respectively) and the notch width index (p < 0.001 and p = 0.002, respectively). No significant correlations were found between tunneling and geometric factors, and clinical scores or SS-D. Graft impingement on the anterior tibial tunnel relative to the end of the intercondylar roof and narrow notch was a more significant contributing factor on increased signal intensities of the ACL graft, compared with the acute femoral bending angle in remnant-preserving outside-in ACLR. Therefore, surgeons should focus on intercondylar notch anatomy during tibial tunnel placement to avoid roof impingement. Level III.

No increased rate of cyclops lesions and extension deficits after remnant-preserving ACL reconstruction using the sparing technique

BackgroundRemnant-preserving anterior cruciate ligament reconstruction (ACLR) should have advantages for postoperative remodeling and proprioception. However, it has been suggested that the larger diameter of the graft tends to lead to impingement phenomena with a higher rate of cyclops lesions. The aim of this work was to find out whether the remnant-preserving ACLR actually leads to an increased rate of range of motion restraints compared to the remnant-sacrificing technique.MethodsPatients, who fulfilled the inclusion criteria, were followed up for one year after surgery. The primary endpoint was arthrolysis due to extension deficit or cyclops syndrome.Secondary outcome measures were pain (NRS), knee function (KOOS), patient satisfaction and return to sports rate.ResultsOne hundred and sixty-four patients were included in the study, 60 of whom received the “remnant augmentation” procedure (group 1). In the remnant augmentation group, one cyclops resection was performed, whereas in the non-remnant augmentation group three cyclops lesion resections had to be performed (odds ratio 0.6). There was no difference between the groups in pain (NRS) and knee function (KOOS) and patient satisfaction. The return to sports rate after one year was higher in the remnant augmentation group.ConclusionsPatients who have undergone the sparing “remnant augmentation” ACLR have no increased risk of cyclops lesion formation or extension deficit in the first year after surgery. An improvement of the proprioceptive abilities by remnant augmentation ACLR should be investigated in further studies.Level of evidenceIII (prospective cohort study).

Effect of a new remnant-preserving technique with anatomical double-bundle anterior cruciate ligament reconstruction on MRI-based graft maturity: a comparison cohort study.

To investigate the effects of a new remnant-preserving double-bundle anterior cruciate ligament reconstruction (ACLR) technique, focused on avoiding remnant damage and preserving continuity of remnants, on graft maturity using magnetic resonance imaging (MRI). A total of 169 patients were divided into three groups: 41 in the preservation group, 70 in the resection group, and 58 in the absent group. In the preservation group, rather than passing the graft through the remnant tissue, the graft was reconstructed such that the anteromedial and posterolateral bundles sandwiched the remnant to avoid damage to the remnant and maintain its continuity. Based on 1-year postoperative MRI, the grafts were divided into three regions: distal, middle, and proximal. The signal/noise quotient (SNQ) of each region of interest was calculated to evaluate the signal intensity of the graft and was compared among the three groups. Additionally, to identify factors influencing graft maturity, a multiple regression analysis was performed with SNQ as the dependent variable and patient demographics, bone morphology, and surgical factors as independent variables. In a three-group comparison of mean SNQs, the distal region was 3.3 ± 3.4, 8.9 ± 8.3, and 9.0 ± 8.6 (p < 0.001), the middle region was 5.3 ± 3.7, 10.9 ± 11.1, and 11.3 ± 10.2 (p < 0.001), and the proximal region was 6.8 ± 4.5, 11.1 ± 8.8, and 11.7 ± 10.8 (p = 0.017), in order of the preservation, resection, and absent groups, respectively. That indicated that the remnant-preserving ACLR was more hypointense than ACLR with remnant resection or absent in all three regions. Multiple regression analysis showed that remnant preservation remained the relevant factor affecting SNQ of the graft at the distal and middle levels. The new remnant-preserving anatomic double-bundle ACLR had significantly better graft maturity, measured by SNQ on MRI, than the remnant resection and absent groups. The remnant procedure was the relevant factor affecting graft maturity. Level III.

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

The occurrence rate of cyclops lesion after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction with remnant tissue preservation remains unclear. 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. 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. Cohort study; Level of evidence, 3. 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). 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.

Functional result of anterior cruciate ligament reconstruction by remnant preservation in a tertiary center in Eastern India

&lt;p&gt;&lt;strong&gt;Background:&lt;/strong&gt; Anterior cruciate ligament (ACL) reconstruction is one of the most common procedures in orthopaedics. Orthopaedic surgery is vastly evolving to give better functional outcome. Apart from stability, proprioception, ligament healing are important factors for return to sports. The presence of remnant containing mechanoreceptors and free neural endings can help reinnervate the ACL auto graft. Aims and objectives were to evaluate clinical outcomes in patients undergoing ACL reconstruction with remnant preservation.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods&lt;/strong&gt;: One hundred and six patients who underwent ACL reconstruction between April 2014 and March 2020. Among these 80 patients underwent remnant preservation. Analysis is done based on international knee documentation committee score (IKDC), modified Cincinnati knee rating system (MCKRS) and Tegner-Lysholm scoring system. Other factors are Lachman test, pivot shift test, return to sports and graft rupture rate.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt; Lachman test became negative in 98% at 12 weeks and in all the patients at 24 months post-operatively. 74 patients (92.5%) among 80 patients develop full range of knee movement after ACL surgery. Post-operative scores are 95, 93, and 92 respectively.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;Remnant preserving ACL reconstruction having excellent clinical outcome with good knee stability, early return to sports activities and no incidence of graft rupture in our series.&lt;/p&gt;

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

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). 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. One hundred and forty-four patients were available at a mean of 30.2 ± 10.1months: 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.). 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. II.

Quantitative assessment of neural elements in a rat model using nerve growth factor after remnant-preserving anterior cruciate ligament reconstruction: a histological and immunofluorescence pilot study

BackgroundImmunofluorescence analyses of anterior cruciate ligament (ACL) allografts following remnant-preserving ACL reconstruction using Achilles tendon allografts have provided evidence for the presence of neural elements. In this study, we aimed to examine the expression of neural elements and quantify the presence of neural cells in ACL remnants and Achilles allografts using nerve growth factor (NGF) therapy after remnant-preserving ACL reconstruction.MethodsExperiments were conducted on 5 pairs of rats (approximately 8 weeks old and weighing 320 g at the time of surgery). Longitudinally, split Achilles tendons from the paired rats were freshly frozen and later defrosted with warm saline and allografted onto the right ACL of the other rat that was partially detached at the femoral attachment site. A sham operation was conducted on the left knee to be used as a control. NGF was injected into both knee joints every week for 6 weeks after surgery. The presence of neural cells in the ACL of the sham-operated knee, allografted Achilles tendon, and ACL remnant was examined 6 weeks post-surgery using H and E and immunofluorescent staining.ResultsH and E staining did not reveal neural cells in any of the three groups. However, immunofluorescence analysis showed the presence of nestin-positive neural elements in the normal ACL tissues as well as ACL remnants. Additionally, neural elements were examined in 7 of the 8 (87.5%) allograft tissues. Quantitative analysis showed no difference in the number or area of nuclei among the three groups. However, the number and area of neural cells in the Achilles allografts were significantly lower than those in the other two groups (p = 0.000 and p = 0.001, respectively).ConclusionOur observations indicate that ACL remnants promote the new ingrowth and persistence of neural cells. We suggest that the ingrowth of neural elements can support the persistence and new ingrowth of mechanoreceptors, thereby enhancing the functional stability of knee joints. Moreover, the expression of neural cells in the Achilles allografts was lower than that in normal ACL tissues and ACL remnants in the quantitative evaluation, thereby confirming the essential role of ACL remnants in knee joint functionalization.

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.

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

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. 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. Retrospective chart review. Inpatient orthopedic surgical and rehabilitation clinic. The subjects were 644 patients who underwent primary ACLR. The independent variables were age, height, and body weight of the subjects, and the presence of remnant tissue. 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. 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). 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.

Femoral tunnel placement in single-bundle, remnant-preserving anterior cruciate ligament reconstruction using a posterior trans-septal portal

BackgroundAnatomic tunnel formation and remnant preservation are valuable aspects of anterior cruciate ligament (ACL) reconstruction. However, anatomic landmarks are difficult to observe during remnant-preserving ACL reconstruction (ACLR). The aims of this study were to evaluate the: 1) femoral tunnel location created with guidance from the apex of the deep cartilage margin (ADC) and footprint compared to anatomical reference; and 2) relationship between femoral tunnel location and outcomes of ACLR. MethodsA total of 109 ACLR patients without revision ACLR, multi-ligament reconstruction, peri-knee fracture, and osteotomy were included. The femoral tunnel was formed at the most proximal corner of the femoral footprint using a posterior trans-septal portal as the viewing portal. The distance from the tunnel center to ADC was measured by computed tomography and arthroscopy. The two measurements were then compared. Finally, femoral tunnel location was compared to the anatomic reference and correlated with the outcomes. ResultsThe average distance from ADC to the femoral tunnel center was 7.0 ± 1.4 mm as measured by arthroscopy, and 7.2 ± 2.0 mm using three-dimensional computed tomography. There was no statistically significant difference between the two methods (P = 0.420). Clinical and stability outcomes were significantly improved postoperatively. Clinical outcome was not related to femoral tunnel location; however, stability outcome was related to femoral tunnel location: the more proximally located femoral tunnels showed better stability. ConclusionThe ADC can be a possible landmark in remnant-preserving ACLR using a trans-septal portal. A more proximal femoral tunnel, which is located at the proximal corner of the ACL remnant, can provide stability advantage during remnant-preserving ACLR.

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

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

Effects of Remnant Tissue Preservation on Tunnel Enlargement After Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction Using the Hamstring Tendon.

Background:The effects of remnant tissue preservation on tunnel enlargement after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction have not yet been established.Hypothesis:The preservation of ACL remnant tissue may significantly reduce the degree and incidence of tunnel enlargement after anatomic double-bundle ACL reconstruction, while the remnant-preserving procedure may not significantly increase the incidence of tunnel coalition after surgery.Study Design:Cohort study; Level of evidence, 2.Methods:A total of 79 patients underwent anatomic double-bundle ACL reconstruction. Based on the Crain classification of ACL remnant tissue, 40 patients underwent the remnant-preserving procedure (group P), and the remaining 39 patients underwent the remnant-resecting procedure (group R). There were no differences between the 2 groups concerning all background factors, including preoperative knee instability and intraoperative tunnel positions. All patients were examined using computed tomography and a standard physical examination at 2 weeks and 1 year after surgery.Results:During surgery, the femoral and tibial anteromedial (AM) tunnel sizes in both groups averaged 6.6 and 6.5 mm, respectively. The femoral and tibial posterolateral (PL) tunnel sizes in both groups averaged 6 and 6 mm, respectively. There were no differences in the intraoperative tunnel positions and tunnel sizes between groups. Concerning the femoral AM tunnel, the degree of tunnel enlargement in the oblique coronal and oblique axial views in group P was significantly less than that in group R (P = .0068 and .0323, respectively). Regarding the femoral AM tunnel cross-sectional area, the degree and incidence of tunnel enlargement in group P were significantly less than those in group R (P = .0086 and .0278, respectively). There were no significant differences in tunnel coalition between groups. In each group, there were no significant relationships between tunnel enlargement and each clinical outcome.Conclusion:Remnant preservation in anatomic double-bundle ACL reconstruction reduced enlargement of the femoral AM tunnel and did not increase the incidence of tunnel coalition. This is one of the advantages of remnant-preserving ACL reconstruction.

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.

The Influence of Anterior Cruciate Ligament Remnant on Postoperative Clinical Results in Patients with Remnant Preserving Anterior Cruciate Ligament Reconstruction.

BACKGROUND:Anterior Cruciate Ligament (ACL) remnants have important biomechanical, vascular and proprioceptive function.AIM:To determine the influence of the ACL residual remnants after partial and complete ACL ruptures on postoperative clinical results in patients with remnant preserving ACL reconstruction.PATIENTS AND METHODS:The study included 66 patients divided into two groups. In patients from the investigation group remnant preserving ACL reconstruction was performed, in patients from the control group single bundle ACL reconstruction was performed. The results were assessed by Rolimeter measurements, Lysholm and Tegner scores and proprioception evaluation.RESULTS:The mean side-to-side difference of anterior tibia displacement (mm) was improved from 4.4 ± 1.06 to 0.4 ± 0.7 in the investigation group, and from 4.6 ± 0.68 to 1.9 ± 0.64 in the control group (p < 0.001). Difference in the angles in which the knee was placed by the device and the patient has improved from 1.5 ± 0.96° to 0.5 ± 0.53° in the investigation group and from 1.8 ± 0.78° to 1.3 ± 0.97° in the control group (p < 0.05). Tegner and Lysholm scores showed no difference between the groups.CONCLUSION:Preservation of the ACL residual bundle provides a better knee stability and proprioceptive function.

Immunohistochemical and immunocytochemical study of mechanoreceptors in anterior cruciate ligament reconstruction with the remnant-preserving technique using Achilles tendon allografts

BackgroundAttempts have been made to validate the significance of remnant preservation with anterior cruciate ligament (ACL) reconstruction using immunohistochemical and immunocytochemical techniques. The purpose of this study was to examine the expression of mechanoreceptors in the remnant tissue of ACL reconstruction performed with the remnant-preserving technique.MethodsTissue samples were obtained from 10 patients who underwent ACL reconstruction with the remnant-preserving technique. The specimens were obtained from remnant ACL tissue and Achilles allografts superficially and at the tibial attachment. The control group consisted of three normal ACLs procured from young males who underwent partial meniscectomy. Tissues and cells from the ACL remnants and Achilles allografts were characterized using hematoxylin and eosin (H&E) staining and immunohistochemical, immunocytochemical, and immunoblotting assays. In particular, the sensitivity of neural cell validation was improved using nerve growth factor (NGF) to stimulate the expression of neural cells.ResultsThe results are summarized as follows. (1) In H&E staining and immunohistochemical assays, no neural cells were detected in remnant or allograft tissue. (2) In the immunocytochemical study, neural cells were detected in remnant tissue. (3) The increased proliferation of remnant ACL cells with NGF treatment suggested their identity as neural cells. (4) NGF treatment also stimulated protein and RNA expression of Nestin (a specific marker for neural cells) in remnant ACL cells.ConclusionsThe improved immunocytochemical methodology proved useful. Although mechanoreceptors were detected relatively less frequently than expected, the authors consider that this finding does not negate the necessity of remnant-preserving ACL reconstruction.

No evidence that remnant-preserving anterior cruciate ligament reconstruction ensures better proprioceptive function than a standard single-bundle reconstruction: a systematic review of randomised controlled trials

ImportanceInjury to the anterior cruciate ligament (ACL) causes significant mechanical instability and unequal functional deficits in patients with similar injury due to loss of proprioception. Therefore, the importance of the ACL remnant has been emphasised; it has the perceived potential to improve postoperative proprioception in knees with ACL reconstruction. However, the current literature shows unproven benefits of doing so, and thus the need for a systematic review.ObjectiveThe purpose of this systematic review was to review published randomised control trials (RCTs) to determine whether a remnant-preserving ACL reconstruction offers any proprioceptive benefit over a standard single-bundle ACL reconstruction.Evidence reviewThe PRISMA checklist was used for all aspects of this systematic review. The PubMed, EMBASE, Cochrane and HuGE databases were searched from their inception until 15 June 15 2016 with specific keywords. Trial registry databases were also searched.FindingsThe initial search yielded 3081 articles. Out of these 2841 did not relate to the research question and were removed. The remaining 240 articles were screened for their abstracts. 178 articles which were either non-clinical studies or not related to ACL remnant preservation and proprioception were excluded. For the remaining 62 studies, full-text articles were studied and 57 were excluded from the study as they were not RCTs or dealt with remnant preservation techniques only in isolation or were non-comparative outcome studies or reviews. That left 5 RCTs. Out of these, 4 did not deal with proprioception as an outcome measure and were excluded. This left only 1 RCT by Hong et al available for the review.Conclusions and relevanceAt present there is no direct evidence to favour or refute ACL remnant preservation at the time of reconstruction.

A Comparative Animal Study of Tendon Grafts Healing After Remnant-Preserving Versus Conventional Anterior Cruciate Ligament Reconstruction.

BackgroundThe aim of this study was to determine if anterior cruciate ligament (ACL) reconstruction by remnant preservation promotes cell proliferation, vascularization, proprioception recovery, and improved biomechanical properties of the tendon grafts.Material/Methods75 New Zealand rabbits were randomly assigned into the control group (group A), conventional ACL reconstruction group (group B), ACL reconstruction using remnant preservation and graft through remnant sleeve technique group (group C), and ACL reconstruction using remnant preservation and remnant tensioning technique group (group D). The remnant and healing of tendon grafts in groups C and D were observed at 3, 6, and 12 weeks after surgery, and the mRNA expression levels of VEGF, NT-3 and GAP-43 in ACL (group A) or tendon graft samples (groups B, C, and D) were determined by real-time PCR. Tendon graft cell count, microvessel density (MVD), and proprioceptors were determined by H&E staining, CD34, and S-100 immunohistochemical staining. The biomechanical properties of the tendon graft at week 12 in groups B, C, and D were examined by using a tensile strength test.ResultsRemnant and tendon grafts were not healed at 3, 6, and 12 weeks after the operation in groups C and D. VEGF, NT-3, and GAP-43 mRNA expressions in groups B, C, and D were higher than those in group A (P<0.05), but no significant difference was observed between groups B, C, and D (P>0.05). Furthermore, tendon graft cell count, MVD, proprioception, and biomechanical properties showed no significant differences (P>0.05) among groups B, C, and D at various time points.ConclusionsThere was no significant difference in cell proliferation, vascularization, proprioception recovery, or biomechanical properties of the tendon grafts between remnant-preserving and conventional ACL reconstruction methods.