Remnant Preservation Research Articles

Remnant preservation does not affect accuracy of tibial tunnel positioning in single-bundle ACL reconstruction.

Remnant preservation, in anterior cruciate ligament (ACL) reconstruction, has potential biological advantages. However, graft positioning remains vital to functional outcome and the prevention of failure. The aim of this study was to investigate the accuracy and precision of tibial tunnel positioning in remnant preservation single-bundle hamstring reconstruction. Fifty consecutive adult patients, with isolated ACL rupture, were recruited to a prospective study. Remnant preservation was performed in all cases where > 25% of the native ACL was present. Three-dimensional computer tomography was preformed 3-6months post-operatively to assess tibial tunnel position (using a grid-based measurement). Accuracy and precision of this technique were assessed against published anatomical data in direct comparison with the group where remnant preservation could not be performed. Two patients withdrew following surgery. In the remaining groups (31 remnant preservation; 17 non-remnant preservation), no difference was demonstrated in tunnel position (40.4 ± 6.7% (anterior-to-posterior) and 47.4 ± 1.5% (medial-to-lateral) vs. 38.8 ± 4.9% and 46.7 ± 1.5%, respectively; n.s.), accuracy (6.1% vs. 4.8%; n.s.) or precision (3.9% vs. 2.8%; n.s.). Remnant preservation can be safely performed without compromising tunnel position. Therefore, the potential benefits of this technique can be utilised, in clinical practice, without sacrificing the ability to optimize tibial tunnel positioning. III.

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.

Biomechanical and Histopathological Analysis on Different Approaches for Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) injury is one of the common injuries in sports and vehicle accidents. ACL decreases joint stability, leading to increased incidence of osteoarthritis. Although there are various approaches for the reconstruction of ACL, no consensus has been reached on the safest and most effective method to achieve joint stability. Here we have compared the biomechanical and histopathological outcomes of three different approaches: intra-articular ACL reconstruction, remnant-preserving and re-tensioning and non-remnant-preservation technique, using finite element analysis, histopathologic observation as well as qPCR and western blot analysis. Results of the current study showed no significant differences among the three methods concerning biomechanical, histopathological analysis and mRNA and protein levels of chondrocyte apoptotic markers such as JNK, MMP-1 and SIRT1 (P > 0 05). Those results indicated that remnant preservation techniques such as intra-articular ACL reconstruction and remnant-preserving and re-tensioning are similar in their ability to achieve joint stabilization and prevent chondrocyte regeneration to non-remnantpreservation technique.

Remnant Tendon Preservation Enhances Rotator Cuff Healing: Remnant Preserving Versus Removal in a Rabbit Model

To assess whether anatomic repair preserving remnant tendon tissue can enhance tendon-to-bone healing biomechanically and histologically in a rabbit rotator cuff tear model. In this controlled laboratory study, bilateral infraspinatus tenotomy from the greater tuberosity, with remnant tendon on the footprint, was performed in 26New Zealand white rabbits. An open transosseous technique was used to perform bilateral infraspinatus tendon repair 1 week later. Preservation and removal of the remaining tendon were performed on the left and right sides, respectively. Seven rabbits each were killed humanely for biomechanical testing and 6 rabbits each were killed humanely for histologic evaluation at 4 and 12 weeks. Significantly superior biomechanical properties were shown in the remnant tissue-preservation group at 4 and 12 weeks in terms of maximum load (89.6 ± 24.3 N vs 68.2 ± 20.7 N at 4 weeks, P=.048; 120.8 ± 27.5 N vs 93.3 ± 25.1 N at 12 weeks, P= .035) and stiffness (25.3 ± 3.4 N/mm vs 17.7 ± 5.2 N/mm at 4weeks, P= .009; 26.7 ± 5.2 N/mm vs 19.4 ± 5.2 N/mm at 12 weeks, P < .001). Improved bone-tendon interface histologic maturity scores (14.8 ± 0.9 vs 8.2 ± 1.5 at 4 weeks, P= .027; 16.8 ± 0.7 vs 10.5 ± 1.4 at 12 weeks, P= .027) and large metachromasia areas (0.117 ± 0.053 mm2 vs 0.032 ± 0.017 mm2 at 4 weeks, P= .022; 0.14 ± 0.046 mm2 vs 0.037 ± 0.016 mm2 at 12 weeks, P= .007) were obtained in the preservation group compared with the removal group at 4 and 12 weeks. This study showed that preserving remnant tissue in anatomic repair can significantly improve rotator cuff healing compared with remnant tissue removal on the footprint in terms of biomechanical properties, bone-tendon interface histologic maturity scores, and metachromasia at 4 and 12 weeks after repair in a rabbit rotator cuff tear model. The results suggest that preservation of remnant tissue on the footprint containing the native bone-tendon interface, when present, may be a better option for rotator cuff healing in rotator cuff repair surgery.

Arthroscopic Standard Anterior and Posteromedial Portal Posterior Cruciate Ligament Reconstruction With Remnant Preservation : 2-Year Follow-up

BACKGROUND: Grade 3 posterior cruciate ligament (PCL) injury needs surgical intervention, but there is no consensus on the optimal technique in PCL reconstruction. The old technique always removes the remnant for good visualization of tunnel replacement. Recently, many studies proposed the concept of preservation of PCL remnant with achieve good visualization.&#x0D; AIM: The aim of the study is to evaluate PCL reconstruction with remnant preservation using the standard anterior and posteromedial portal at 2-year follow-up.&#x0D; METHODS: We conducted a cohort retrospective study between January 2013 and December 2015. In this study, 25 patients underwent PCL reconstruction using the standard anterior and posteromedial portal with remnant preservation. We used quadrupled hamstring autograft. The patients were assessed using the International Knee Documentation Committee (IKDC) score, Lysholm Knee Score, Modified Cincinnati Score, and knee society score (KSS) at pre-operative and 2-year post-operative. Range of motion (ROM) and complications were evaluated postoperatively.&#x0D; RESULTS: The mean diameter of the quadruple hamstring graft was 8 mm. Clinical outcomes enhanced significantly (p &lt; 0.05). The average of Lysholm activity scale improved from 65.12 ± 10.48 to 94.96 ± 4.80. The IKDC score improved from 60.50 ± 15.10 to 95.60 ± 3.44. Modified Cincinnati score improved from 62. 28 ± 13.6 to 96.04 ± 1.62. The KSS also improved from 60.12 ± 18.01 to 94.88 ± 6.36. Twenty-two patients had 0–135° full ROM and three patients had 0–110° ROM. Two patients had surgical site infection but recovered with local debridement.&#x0D; CONCLUSION: PCL reconstruction using the standard anterior and posteromedial portal with remnant preservation at 2-year follow-up resulted in satisfactory clinical and functional outcomes.

Arthroscopic Primary Repair of the Anterior Cruciate Ligament With Single-Bundle Graft Augmentation

Recently, there has been a resurgence of interest in ligament preservation of the anterior cruciate ligament (ACL) that has the advantage of preserving the native tissue and maintaining proprioceptive function. Studies reporting outcomes of remnant-preserving ACL surgery have shown encouraging results with a higher potential for early healing and better functional outcomes compared with remnant-resecting surgery. Over the past decade, several surgical techniques for remnant preservation of the ACL have been proposed. In this technical note, the technique of primary ACL repair with graft augmentation is described. The goal of this technique is to preserve and tension the native tissue, thereby restoring the anatomy as much as possible while avoiding cyclops lesions, whereas the additional graft provides strength to the repaired ligament.

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.

The effect of interleukin-8 in the early stage after anterior cruciate ligament reconstruction with remnant preservation

PurposeWe studied the effect of interleukin-8 (IL-8) as the factor for angiogenesis in the joint fluid of remnant-preserved anterior cruciate ligament reconstruction (RP-ACLR).Materials and methodsWe measured 12 cytokines in joint fluid by multiplex assay and assessed the relationship between IL-8 and vascular endothelial growth factor (VEGF) concentrations. The signal intensity and mean sagittal diameter via postoperative magnetic resonance imaging (MRI) scans were evaluated and the stress X-ray image was analyzed at 3, 6, and 12 months after operation.ResultsThe IL-8 concentration was highest 3 months postoperatively in those patients who underwent RP-ACLR. Clinical data also showed that the signal intensity and stress radiography of the knee graft were significantly better at the early postoperative stage.DiscussionOur results show that IL-8 plays an important role in angiogenesis within 3 months after RP-ACLR. This effect yields better recovery after operation. RP-ACLR patients with high knee stability in clinical data were identical to those with high expression of IL-8 in experimental data. Therefore, IL-8 has been shown to help revascularization and ligamentization of the grafted tendon. These results indicate that IL-8 in RP-ACLR is an important factor for angiogenesis after operation. Unfortunately, the relationship of IL-8 and VEGF in vivo has not been studied.ConclusionOur results showed that the IL-8 concentration was very high within 3 months after RP-ACLR operation. The increase in concentration of IL-8 over time was consistent with the increase in VEGF concentration. In the IL-8 clinical setting, MRI analysis showed that ACL synovialization and tension were better in patients who underwent the remnant preservation method. In addition, it was shown that RP-ACLR may be advantageous for early anterior stability within 1 year post operation and beneficial for tendon graft in the early stage post operation. Taken together, our findings suggest that IL-8 may contribute to angiogenesis which is helpful for revascularization and ligamentization of the graft tendon in the early stages of RP-ACLR.

To compare the results of anterior cruciate ligament reconstruction with preservation versus total removal of torn anterior cruciate ligament stump

PURPOSE: Reconstruction of anterior cruciate ligament (ACL) with torn ligament remnant preservation is done with the aim to improve the proprioceptive function and vascularization of new graft. In our study, we compared the results of ACL reconstruction with and without preservation of femoral and tibial ACL torn stumps.MATERIALS AND METHODS: This is a prospective study consisting of 100 patients distributed into two groups. Group A (n = 50) underwent reconstruction of ACL with remnant stump preservation and Group B (n = 50) underwent reconstruction of ACL with total removal of ACL remnant from the femur and tibia.RESULTS: The present study did not show any significant differences in terms of stability and ACL laxity in the study groups. However, a remarkable difference was noted in proprioception and functional results in both the groups, with Group A (>20%) showing better results.CONCLUSION: Based on our study, we can conclude that it is judicious to keep ACL stump as much as possible, and it is advisable to wait till 4 weeks to get inflammatory phase subsided. Preservation of remnant should not interfere with ACL footprint visualization. Remnant preservation improves proprioception of the knee and functional outcome.

ACL reconstruction preserving the ACL remnant achieves good clinical outcomes: A case control study

Introduction: Orthopaedic surgeons have been trying hard to optimize the technique of ACL reconstruction to have better functional outcome. In addition to stability a high quality of proprioception is also required. The presence of remnant containing mechanoreceptors and free neural endings, can help reinnervate the ACL autograft. Aims & Objectives: To compare clinical outcomes in patients undergoing ACL reconstruction with or without remnant preservation. Materials & Methods: 86 patients who underwent ACL reconstruction between September 2016 and March 2018. These patients were divided into 2 groups : those in whom the remnant was preserved (group 1 = 22) and those in whom the remnant was not preserved (group 2= 64). Patients were followed up for atleast 18 months. Results: The Tegner Lysholm score was higher in group 1 than group 2 (p

Arthroscopic Standard Anterior and Posteromedial Portal Posterior Cruciate Ligament Reconstruction With Remnant Preservation: 2-Year Follow-up

Background: Grade 3 Posterior Cruciate Ligament (PCL) injury needs surgical intervention, but there is no consensus on the optimal technique in PCL reconstruction. The old technique always removes the remnant for good visualization of tunnel replacement. Recently, many studies proposed the concept of the preservation of PCL remnant with achieving good visualization. The aim of the study is to evaluate PCL reconstruction with remnant preservation using the standard anterior and posteromedial portal at 2-years follow-up. Methods: We conducted a cohort retrospective study between January 2013 to December 2015. In this study, 25 patients underwent PCL reconstruction using standard anterior and posteromedial portal with remnant preservation. We used quadrupled hamstring autograft. The patients were assessed using the International Knee Documentation Committee (IKDC) score, Lysholm knee score, Modified Cincinnati Score, and Knee Society Score (KSS) at pre-operative and 2-years post-operative. Range of Motion (ROM) and complication were evaluated post-operatively. Results: The mean diameter of the quadruple hamstring graft was 8 mm. Clinical outcomes enhanced significantly (p&lt;0.05). The average Lysholm activity scale improved from 65.12 ± 10.48 to 94.96 ± 4.80. The International Knee Documentation Committee (IKDC) score improved from 60.50 ± 15.10 to 95.60 ± 3.44. The Modified Cincinnati Score improved from 62. 28 ± 13.6 to 96,04 ± 1.62. The KSS also improved from 60.12 ± 18.01 to 94.88 ± 6.36. 22 patients had 0-135° full ROM and 3 patients had 0-110° ROM. Two patients had surgical site infection but recovered with local debridement. Conclusion: PCL reconstruction using standard anterior and posteromedial portal with remnant preservation at 2 years follow up resulted in satisfactory clinical and functional outcomes.

Anatomical Arthroscopic Anterior Talofibular Ligament Repair and Reconstruction Using a Free Tendon

Arthroscopic techniques for anterior talofibular ligament (ATFL) repair and reconstruction have been developed in recent years. We simultaneously performed anatomical arthroscopic ATFL repair and reconstruction using a free tendon graft. The ATFL remnant is carefully dissected only at the footprint of the superior limb of the ATFL, and a bone tunnel is created on each side of the fibula and talus. A soft suture anchor with 2 sets of threads is inserted into the fibular tunnel. One set of threads is used to grab the ATFL remnant via a lasso-loop technique, whereas the other set of threads is used to introduce the ATFL graft. The graft is first fixed with a screw in the talar tunnel. Subsequently, the ATFL remnant and the graft are tightened simultaneously by pulling the 2 sets of suture anchor threads at the fibular tunnel and are fixed with a screw. This technique provides the possible advantages of remnant preservation and promotion of load sharing by the repaired ATFL remnant and the reconstructed ATFL graft.

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.

Primary ACL Repair Revisited: Back to the Future?

Primary repair of the Anterior Cruciate Ligament (ACL) had some popularity among a select group of surgeons in the mid 20th century. Techniques described by Ivar Palmer of Sweden were adopted in the United States by surgeons such as O’Donoghue, Marshall, and Feagin. However, promising early results were followed by disappointing failure rates at 5-year follow-up, and ACL reconstruction became the norm. Recently there has been a renewed interest in ACL repair. One use has been in conjunction with ACL reconstruction as remnant preservation. Isolated repair has been reported using a variety of techniques, including bridge-enhanced repair (BEAR) with a sheath, meticulous suturing with or without suture tape reinforcement, and repair to a dynamic intraligamentary stabilization (DIS) device. Early reports have been encouraging. However, in the case of the BEAR, the series is so far small and short-term; the two other techniques have more results reported but they include some studies with a concerning level of failure, especially in younger or more active patients. My current recommendation is to await more clinical documentation before adopting these technique in lieu of ACL reconstruction.

The femoral posterior fan-like extension of the ACL insertion increases the failure load.

To examine the role of the posterior fan-like extension of the ACL's femoral footprint on the ACL failure load. Sixteen (n = 16) fresh frozen, mature porcine knees were used in this study and randomized into two groups (n = 8): intact femoral ACL insertion (ACL intact group) and cut posterior fan-like extension of the ACL (ACL cut group). In the ACL cut group, flexing the knees to 90°, created a folded border between the posterior fan-like extension and the midsubstance insertion of the femoral ACL footprint and the posterior fan-like extension was dissected and both areas were measured. Specimens were placed in a testing machine at 30° of flexion and subjected to anterior tibial loading (60mm/min) until ACL failure. The intact ACL group had a femoral insertion area of 182.1 ± 17.1mm2. In the ACL cut group, the midsubstance insertion area was 113.3 ± 16.6mm2, and the cut posterior fan-like extension portion area was 67.1 ± 8.3mm2. The failure load of the ACL intact group was 3599 ± 457N and was significantly higher (p < 0.001) than the failure load of the ACL cut group 392 ± 83N. Transection of the posterior fan-like extension of the ACL femoral footprint has a significant effect on the failure load of the ligament during anterior loading at full extension. Regarding clinical relevance, this study suggests the importance of the posterior fan-like extension of the ACL footprint which potentially may be retained with remnant preservation during ACL reconstruction. Femoral insertion remnant preservation may allow incorporation of the fan-like structure into the graft increasing graft strength.

Restorative Possibilities Using Zirconia Ceramics for Single Crowns.

Two clinical cases are presented to explore technical differences and discusses the advantages and disadvantages of using veneered or monolithic zirconia to manufacture posterior single crowns. The first case describes the clinical steps in manufacturing a monolithic crown on a mandibular left second premolar using high translucency zirconia. It shows the use of a conservative tooth preparation based on the superior mechanical properties that this material presents as well as the final optical characteristics achieved by shading and staining. In the second case, a conventional bilayer restorative treatment was made using zirconia framework followed by veneering with feldspar ceramic on a mandibular left first molar. Recent literature indicates that each of these restorative alternatives presents specific advantages and disadvantages. Factors such as mechanical performance, fracture, esthetic characteristics, clinical success, complication rates, adhesion and antagonist wear performance are discussed comparing the two restorative assemblies. The data highlight that monolithic crowns prevent a major problem reported on bilayer restorations: the chipping of veneering ceramic. Monolithic crowns also allow minimally invasive tooth preparations, thus increasing tooth remnant preservation. However, data that support esthetic performance similarity between monolithic and bilayer assemblies are lacking, thus the predictability of use is restricted for the posterior region, as cases demanding high esthetic appeal continue to fundamentally use bilayer restorations. Failures were not found, and patient satisfaction was reported in both techniques after the 12-month follow up.

Anterior cruciate ligament grafts display differential maturation patterns on magnetic resonance imaging following reconstruction: a systematic review.

The appearance of anterior cruciate ligament (ACL) grafts on magnetic resonance imaging (MRI) is related to graft maturity and mechanical strength after ACL reconstruction (ACLR). Accordingly, the purpose of this review was to quantitatively analyze reports of serial MRI of the ACL graft during the first year following ACLR; the hypothesis tested was that normalized MRI signal intensity would differ significantly by ACL graft type, graft source, and postoperative time. PubMed, Scopus, and CINAHL were searched for all studies published prior to June 2018 reporting MRI signal intensity of the ACL graft at multiple time points during the first postoperative year after ACLR. Signal intensity values at 6 and 12months post-ACLR were normalized to initial measurements and analyzed using a least-squares regression model to study the independent variables of postoperative time, graft type, and graft source on the normalized MRI signal intensity. An effect of graft type (P = 0.001) with interactions of graft type * time (P = 0.012) and graft source * time (P = 0.001) were observed. Post hoc analyses revealed greater predicted normalized MRI signal intensity of patellar tendon autografts than both hamstring (P = 0.008) and hamstring with remnant preservation (P = 0.001) autografts at postoperative month 12. MRI signal varies with graft type, graft source, and time after ACLR. Enhanced graft maturity during the first postoperative year was associated with hamstring autografts, with and without remnant preservation. Serial MRI imaging during the first postoperative year may be clinically useful to identify biologically or mechanically deficient ACL grafts at risk for failure. IV.

Return to Sports and Clinical Outcomes After Arthroscopic Anatomic Posterior Cruciate Ligament Reconstruction With Remnant Preservation

To evaluate the clinical outcomes of transtibial posterior cruciate ligament reconstruction (PCLR) with remnant preservation in highly active patients and to investigate the rate of return to sports (RTS), quality of sports activities, and patient satisfaction. Patients with a Tegner activity scale of >5 who underwent isolated PCLR from 2013 to 2016 with minimum 2-year follow-up were retrospectively reviewed. Single-bundle PCLR was performed using fresh frozen allograft irradiated with 50kGy. Subjective assessments included the Lysholm score, subjective International Knee Documentation Committee score, and Tegner activity scale. A questionnaire elicited information associated with RTS and satisfaction. Functional tests included isokinetic muscle strength and single-leg hop tests. We evaluated 52patients, with a mean (± standard deviation) follow-up duration of 29.5 ± 8.6months. The subjective assessments andfunctional tests significantly improved postoperatively (all P < .001). Mean time to return to full sports activity was 9.7± 5.1months. Thirty-eight (73.1%) and 45 (86.5%) patients could return to previous sports activities at 9 and 24months, respectively. A sports-experience questionnaire indicated that 48% and 69.2% of the patients were participating with unlimited effort and performance, respectively, and no pain at 9 and 24months. Multivariate analysis indicated that extensor deficit (odds ratio [OR] 4.2, 95% confidence interval [CI] 1.342 to 17.839), flexor deficit at 60°/s (OR 3.8, 95% CI 1.081 to 14.476), Limb Symmetry Index (%) for the single-leg vertical jump test (OR 2.2, 95% CI 1.212 to 9.227), and satisfaction (OR 2.8, 95% CI 1.186 to 10.281) were significantly associated with failure of not returning to preinjury sports activity levels at the 9-month follow-up. Arthroscopic anatomic PCLR with remnant preservation showed high rates of RTS and high patient satisfaction, as well as satisfactory clinical results in highly active patients. This surgical technique could be an effective treatment for grade III posterior cruciate ligament injury in highly active patients. Level IV, therapeutic case series.

Ultrastructural and histological changes in tibial remnant of ruptured anterior cruciate ligament stumps: a transmission electron microscopy and immunochemistry-based observational study.

Anterior cruciate ligament (ACL) rupture is a common injury and has a non-union rate of 40-100%. Important cellular events, such as fibroblast proliferation, angiogenesis and change in collagen fibril thickness in the ACL remnant, as described in other dense connective tissue, might have an implication in graft recovery following ACL reconstruction. Thus we conducted a study with an aim to characterize the ultrastructural and histological features of ruptured ACL tibial stump and correlate the same with the duration of injury. This was a prospective observational study in which 60 ruptured human ACLs were evaluated for collagen fibril thickness, blood vessel density (per mm2) and fibroblast density (per mm2) with the help of transmission electron microscopy, immunohistochemistry via CD34 antibody staining and light microscopy (H&E staining). The findings were correlated with duration of injury. Fifty-four male and six female patients with a mean duration of the injury of 23.01weeks (SD = 26.09; range 2-108weeks) were included for the study and were divided on the basis of duration of injury as follows: Group I (≤6weeks; N = 16), Group II (7-12weeks; N = 18), Group III (13-20weeks; N = 7), Group IV (21-50weeks; N = 12), Group V (> 50weeks; N = 7). A significant correlation was seen with blood vessel density (r = 0.303, p = 0.01) and fibroblast density (r = - 0.503, p = 0.001). Thickness of collagen fibril did not correlate with the duration of injury (r = 0.15, p = 0.23). The thickness of the collagen reached its peak after 50weeks following injury, whereas highest density of blood vessel and fibroblast was seen at 12-20weeks. Matched pair analysis revealed a significant decrease in collagen fibril thickness and an increase in fibroblast density at 7-12weeks. Following injury to ACL, the ruptured tibial stump undergoes a series of changes at the cellular level vis-à-vis changes in collagen fibril thickness, vascular density and fibroblast density that possibly suggest an intrinsic healing response. This further may have implications on the functional outcome following ACL reconstruction with remnant preservation. III.

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.