Dynamic Intraligamentary Stabilization Research Articles

Functional recovery following primary ACL repair with dynamic intraligamentary stabilization

BackgroundRecently, a new technique, dynamic intraligamentary stabilization (DIS) was introduced for the acute repair of ACL ruptures. The purpose of this study was to report the functional recovery for patients undergoing acute anterior cruciate ligament (ACL) repair alongside DIS. MethodsForty five patients sustaining acute ACL rupture and treated with DIS repair were retrospectively evaluated. Limb symmetry index of the hop test as well as knee function by means of range of motion, knee swelling, pain and maximum strength were evaluated. Following completion of the rehabilitation program, the difference in anterior–posterior translation (Δ-AP Translation), IKDC, Tegner score (TAS) was additionally analyzed. ResultsForty five (13 females, 32 males) patients were included in the study. Mean age was 26years (range 18 to 54years). Median time to successfully complete hop test was 22.0weeks (range 11 to 32weeks) postoperatively. Median limb symmetry index 91.6%±8.3%. Median delta anterior-posterior translation compared to the healthy side was plus 0.0mm±1.6mm. Median IKDC was 89.5±6.5. Mean Tegner score (TAS) at 12months of follow-up was seven (range four to nine). Three patients suffered a rerupture during the first 12 postoperative months. ConclusionsDIS technique with proper rehabilitation following acute ACL rupture provides successful functional recovery and low rerupture rate at one-year follow-up.

Five year results of the first ten ACL patients treated with dynamic intraligamentary stabilisation.

BackgroundIn recent years, the scientific discussion has focused on new strategies to enable a torn anterior cruciate ligament (ACL) to heal into mechanically stable scar tissue. Dynamic intraligamentary stabilization (DIS) with LigamysTM was first performed in a pilot study of 10 patients. The purpose of the current study was to evaluate the five year results of this group.MethodsInclusion criteria were an ACL rupture not older than 14 days, patient age <45 years, no previous surgery on the injured knee, and regular participation in sports requiring pivoting of the knee joint. Ten consecutive patients (eight males, two females) underwent surgery between August 2009 and February 2010. They were treated by DIS employing an internal stabilizer to keep the unstable knee in a posterior translation, combined with microfracturing and platelet-rich fibrin induction at the rupture site to promote self-healing. Postoperative clinical outcome [Tegner, Lysholm, International Knee Documentation Committee (IKDC), visual analogue scale patient satisfaction score] and assessment of knee laxity was performed at 3, 6, 12, 24 and 60 months.ResultsMedian patient age at time of surgery was 23.3 years (range 19–41 years). The median time to surgery was 10 days (range 5–13 days). The rupture was located in the middle third of the ligament in seven patients and in the proximal third in three patients. Eight patients showed additional meniscal lesions, which were surgically treated in six patients. Eight of the ten patients reached the five-years follow-up. Median Lysholm score was 100 (range 90–100); the IKDC score was 98.9 (range 79.3–100); Tegner score was 5.5 (range 5–7); median Lachman difference to the other side was 2 mm (range 0–4 mm). Median patient satisfaction was 10 points (range 8–10 pts.). Four of the ten patients underwent metal removal (tibial implant component) after ACL healing and a consequently stable knee joint. Two patients suffered from a re-rupture at 5 months and 4.2 years after surgery and were treated with a bone-tendon-bone ACL graft.ConclusionsDynamic intraligamentary stabilization in ten active patients with a fresh ACL rupture showed a 5-years survival rate of 80 %. At the last follow-up all patients with a functionally healed ACL showed excellent outcomes and satisfaction with regards to the treatment result.

An Assessment of Rehabilitation Protocols following Anterior Cruciate Ligament Reconstruction: A Systematic Review

The present study provided a systematic review with meta-analysis of randomized controlled trials involving the effectiveness of various rehabilitation methods that have been implemented for the treatment of anterior cruciate ligament reconstruction (ACLR). The review of the literature revealed the following as evidence for effective ACLR rehabilitation: early intervention strategy focused on restoring range of motion, muscle strength, and ligament stability with the utilization of closed kinetic chain exercises. The literature supports the use of dynamic intraligamentary stabilization, which should also be implemented in the rehabilitation protocol within the first three months after surgery. The research suggests that the patient should undergo at least 30-90 minutes of cryotherapy immediately following ACLR surgery. There is also some evidence regarding the effectiveness of neuromuscular rehabilitation training programs, but further investigations are needed. Future research should consider the timing of rehabilitation as well as supplemental rehabilitation exercises to continue to improve the quality of care delivered to patients following ACLR.

Collagen application reduces complication rates of mid-substance ACL tears treated with dynamic intraligamentary stabilization.

Dynamic intraligamentary stabilization was recently proposed as an option for the treatment of acute ACL ruptures. The aim of this study was to investigate the feasibility of the procedure in mid-substance ACL ruptures andexamine whether the additional application of a bilayer collagen I/III membrane would provide for a superior outcome. The study group consisted of patients presenting with a mid-substance ACL rupture undergoing dynamic intraligamentary stabilization using the Ligamys™ device along with application of a collagen I/III membrane to the surface of the ACL (group A, n=23). The control group comprised a matched series of patients presenting with a mid-substance ACL rupture also treated by dynamic intraligamentary stabilization Ligamys™ repair, however, without additional collagen application (group B, n=33). Patients were evaluated preoperatively and at 24-month follow-up forstability as well as Tegner and Lysholm scores. Knee laxity was measured as a difference in anterior translation (ΔAP) and pivot shift. Any events occurring during the follow-up period of 24months were documented. Logistic regression of complications was performed, and adjustment undertaken where necessary. A hightotal complication rate of 78.8% was noted in group B, compared to group A (8.7%) (p=0.002). The addition of a collagen membrane was the only independent prognostic factor associated with reduced complications (OR 8.0, CI 2.0-32.2, p=0.003, for collagen-free treatment). In group B, 6 patients suffered a re-rupture with subsequent instability requiring secondary hamstring reconstruction surgery, and 11 developed extension loss requiring arthroscopic debridement, whilstin group A, 2 patients required arthroscopic debridement for loss of exension, with no further encountered complication.Median Lysholm score was significantly higher in group A compared to group B (median 100 range 93-100vs median 95 range 60-100, p=0.03) at final follow-up. A high complication rate following ACL Ligamys™ repair of mid-substance ruptures was noted. Application of a collagen membrane to the surface of the ACL resulted in a reduced incidence of extension deficit and re-ruptures. The results indicate that solitary ACL Ligamys™ repair does not present an appropriate treatment modality for mid-substance ACL ruptures. Collage application proved to providehealingbenefitswith superiorclinicaloutcome after ACL repair. Case control study, Level III.

Knee joint kinematics after dynamic intraligamentary stabilization: cadaveric study on a novel anterior cruciate ligament repair technique.

Dynamic intraligamentary stabilization (DIS) has been introduced for the repair of acute anterior cruciate ligament (ACL) tears as an alternative to delayed reconstruction. The aim of the present study was to compare knee joint kinematics after DIS to those of the ACL-intact and ACL-deficient knee under simulated Lachman/KT-1000 and pivot-shift tests. We hypothesized that DIS provides knee joint kinematics equivalent to an intact ACL. With the use of a robotic knee simulator, knee kinematics were determined in simulated Lachman/KT-1000 and pivot-shift tests at 0°, 15°, 30°, 60°, and 90° of flexion in eight cadaveric knees under the following conditions: (1) intact ACL, (2) ACL deficiency, (3) DIS with a preload of 60N, and (4) DIS with a preload of 80N. Statistical analyses were performed using two-factor repeated-measures analysis of variance. The significance level was set at a p value of <0.05. After DIS with a preload of either 60N or 80N, the anterior translation was significantly reduced in the simulated Lachman/KT-1000 and pivot-shift tests when compared to the ACL-deficient knee (p<0.05). No significant differences were observed between the DIS reconstruction with a preload of 80N and the intact ACL with regard to anterior laxity in either test. However, DIS with a preload of only 60N was not able to restore knee joint kinematics to that of an intact knee in all degrees of flexion. DIS with a preload of 80N restores knee joint kinematics comparable to that of an ACL-intact knee and is therefore capable of providing knee joint stability during ACL healing. DIS therefore provides a new technique for primary ACL repair with superior biomechanical properties in comparison with other techniques that have been described previously, although further clinical studies are required to determine its usefulness in clinical settings.

Dynamic Intraligamentary Stabilization (DIS) for treatment of acute anterior cruciate ligament ruptures: case series experience of the first three years.

BackgroundIn recent years, the scientific discussion has focused on new strategies to enable a torn anterior cruciate ligament (ACL) to heal into mechanically stable scar tissue. Dynamic intraligamentary stabilization (DIS) was first performed in a pilot study of 10 patients. The purpose of the current study was to evaluate whether DIS would lead to similarly sufficient stability and good clinical function in a larger case series.MethodsAcute ACL ruptures were treated by using an internal stabilizer, combined with anatomical repositioning of torn bundles and microfracturing to promote self-healing. Clinical assessment (Tegner, Lysholm, IKDC, and visual analogue scale [VAS] for patient satisfaction scores) and assessment of knee laxity was performed at 3, 6, 12, and 24 months. A one-sample design with a non-inferiority margin was chosen to compare the preoperative and postoperative IKDS and Lysholm scores.Results278 patients with a 6:4 male to female ratio were included. Average patient age was 31 years. Preoperative mean IKDC, Lysholm, and Tegner scores were 98.8, 99.3, and 5.1 points, respectively. The mean anteroposterior (AP) translation difference from the healthy contralateral knee was 4.7 mm preoperatively. After DIS treatment, the mean 12-month IKDC, Lysholm, and Tegner scores were 93.6, 96.2, and 4.9 points, respectively, and the mean AP translation difference was 2.3 mm. All these outcomes were significantly non-inferior to the preoperative or healthy contralateral values (p < 0.0001). Mean patient satisfaction was 8.8 (VAS 0–10). Eight ACL reruptures occurred and 3 patients reported insufficient subjective stability of the knee at the end of the study period.ConclusionsAnatomical repositioning, along with DIS and microfracturing, leads to clinically stable healing of the torn ACL in the large majority of patients. Most patients exhibited almost normal knee function, reported excellent satisfaction, and were able to return to their previous levels of sporting activity. Moreover, this strategy resulted in stable healing of all sutured menisci, which could lower the rate of osteoarthritic changes in future. The present findings support the discussion of a new paradigm in ACL treatment based on preservation and self-healing of the torn ligament.

Mesenchymal stem cells and collagen patches for anterior cruciate ligament repair.

To investigate collagen patches seeded with mesenchymal stem cells (MSCs) and/or tenocytes (TCs) with regards to their suitability for anterior cruciate ligament (ACL) repair. Dynamic intraligamentary stabilization utilizes a dynamic screw system to keep ACL remnants in place and promote biological healing, supplemented by collagen patches. How these scaffolds interact with cells and what type of benefit they provide has not yet been investigated in detail. Primary ACL-derived TCs and human bone marrow derived MSCs were seeded onto two different types of 3D collagen scaffolds, Chondro-Gide(®) (CG) and Novocart(®) (NC). Cells were seeded onto the scaffolds and cultured for 7 d either as a pure populations or as "premix" containing a 1:1 ratio of TCs to MSCs. Additionally, as controls, cells were seeded in monolayers and in co-cultures on both sides of porous high-density membrane inserts (0.4 μm). We analyzed the patches by real time polymerase chain reaction, glycosaminoglycan (GAG), DNA and hydroxy-proline (HYP) content. To determine cell spreading and adherence in the scaffolds microscopic imaging techniques, i.e., confocal laser scanning microscopy (cLSM) and scanning electron microscopy (SEM), were applied. CLSM and SEM imaging analysis confirmed cell adherence onto scaffolds. The metabolic cell activity revealed that patches promote adherence and proliferation of cells. The most dramatic increase in absolute metabolic cell activity was measured for CG samples seeded with tenocytes or a 1:1 cell premix. Analysis of DNA content and cLSM imaging also indicated MSCs were not proliferating as nicely as tenocytes on CG. The HYP to GAG ratio significantly changed for the premix group, resulting from a slightly lower GAG content, demonstrating that the cells are modifying the underlying matrix. Real-time quantitative polymerase chain reaction data indicated that MSCs showed a trend of differentiation towards a more tenogenic-like phenotype after 7 d. CG and NC are both cyto-compatible with primary MSCs and TCs; TCs seemed to perform better on these collagen patches than MSCs.

Dynamic intraligamentary stabilization and primary repair: A new concept for the treatment of knee dislocation

BackgroundTraumatic knee dislocation represents a rare but devastating injury. Several controversies persist regarding type of treatment, surgical timing, graft selection, repair versus reconstruction of the medial and lateral structures, surgical techniques and postoperative rehabilitation. A new technique for primary ACL stabilization, dynamic intaligamentary stabilization (DIS) was developed at the authors’ institution. The purpose of this study was to analyze the clinical and radiological outcomes of surgically treated traumatic knee dislocations by means of the DIS technique for the ACL, primary suturing for PCL, MCL and LCL. MethodsBetween 2009 and 2012, 35 patients treated surgically for traumatic knee dislocation with primary anterior cruciate ligament (ACL) reconstruction with DIS, suturing of the posterior cruciate ligament (PCL) and primary complete repair of collaterals, were evaluated clinically (IKDC score, SF12 health survey, Lysholm score, Tegner score) and radiologically with a mean follow up of 2.2 years (range 1.00–3.50 years) years. Instrumented anterior–posterior translation was measured (KT-2000). ResultsAnterior/posterior translation (KT-2000) for the healthy and injured limb was 4.8mm (range 3–8mm) and 7.3mm (range 5–10) (89N) respectively. Valgus and varus stress testing in 30° flexion was normal in 26 (75%) and 29 (83%) patients, respectively. The IKDC score was B in 29 (83%) and C in 6 (17%) patients, while the mean Tegner score was 6 (range 4–8). The mean Lysholm score was 90.83 (range 81–95) and mean SF-12 physical and mental scores were 54.1 (range 45–60) and 51.0 (range 39–62) respectively. In 2 patients, a secondary operation was performed. ConclusionsEarly, one stage reconstruction with DIS can achieve good functional results and patient satisfaction with overall restoration of sports and working capacity without graft requirements.

Dynamic intraligamentary stabilization: novel technique for preserving the ruptured ACL

PurposeReplacement of the torn anterior cruciate ligament (ACL) with a transplant is today`s gold standard. A new technique for preserving and healing the torn ACL is presented. Hypothesis: a dynamic intraligamentary stabilization (DIS) that provides continuous postinjury stability of the knee and ACL in combination with biological improvement of the healing environment [leucocyte- and platelet-rich fibrin (L-PRF) and microfracturing] should enable biomechanically stable ACL self-healing.MethodsTen sportive patients were treated by DIS employing an internal stabilizer to keep the unstable knee in a posterior translation, combined with microfracturing and platelet-rich fibrin induction at the rupture site to promote self-healing. Postoperative clinical [Tegner, Lysholm, International Knee Documentation Committee (IKDC), visual analogue scale patient satisfaction score] and radiological evaluation, as well as assessment of knee laxity was performed at 6 weeks, 3, 6, 12, and 24 months.ResultsOne patient had a re-rupture 5 months postoperative and was hence excluded from further follow-ups. The other nine patients presented the following outcomes at 24 months: median Lysholm score of 100; IKDC score of 98 (97–100); median Tegner score of 6 (range 9–5); anterior translation difference of 1.4 mm (−1 to 3 mm); median satisfaction score of 9.8 (9–10). MRI showed scarring and continuity of the ligament in all patients.ConclusionsDIS combined with microfracturing and L-PRF resulted in stable clinical and radiological healing of the torn ACL in all but one patient of this first series. They attained normal knee scores, reported excellent satisfaction and could return to their previous levels of sporting activity.Level of evidenceCase series with no comparison group, Level IV.

A novel technique, dynamic intraligamentary stabilization creates optimal conditions for primary ACL healing: A preliminary biomechanical study

BackgroundAnterior cruciate ligament (ACL) rupture is a common lesion. Current treatment emphasizes arthroscopic ACL reconstruction via a graft, although this approach is associated with potential drawbacks. A new method of dynamic intraligamentary stabilization (DIS) was subjected to biomechanical analysis to determine whether it provides the necessary knee stability for optimal ACL healing. MethodsSix human knees from cadavers were harvested. The patellar tendon, joint capsule and all muscular attachments to the tibia and femur were removed, leaving the collateral and the cruciate ligaments intact. The knees were stabilized and the ACL kinematics analyzed. Anterior–posterior (AP) stability measurements evaluated the knees in the following conditions: (i) intact ACL, (ii) ACL rupture, (iii) ACL rupture with primary stabilization, (iv) primary stabilization after 50 motion cycles, (v) ACL rupture with DIS, and (vi) DIS after 50 motion cycles. ResultsAfter primary suture stabilization, average AP laxity was 3.2mm, which increased to an average of 11.26mm after 50 movement cycles. With primary ACL stabilization using DIS, however, average laxity values were consistently lower than those of the intact ligament, increasing from an initial AP laxity of 3.00mm to just 3.2mm after 50 movement cycles. ConclusionsDynamic intraligamentary stabilization established and maintained close contact between the two ends of the ruptured ACL, thus ensuring optimal conditions for potential healing after primary reconstruction. The present ex vivo findings show that the DIS technique is able to restore AP stability of the knee.

Anterior crucial ligament rupture: self-healing through dynamic intraligamentary stabilization technique

Surgery involving arthroscopic reconstruction of the injured ligament is the gold standard treatment for torn anterior cruciate ligament (ACL). Recent studies support the hypothesis of biological self-healing of ruptured ACL. The aim of the study is to evaluate, in an animal model, the efficacy of a new technique, dynamic intraligamentary stabilization that utilizes biological self-healing for repair of acute ACL ruptures. The ACL in 11 adult female white alpine sheep was transected and in 8 sheep reconstructed by dynamic intraligamentary stabilization. To enhance the healing potential, microfracturing and collagen were used in all animals. The contralateral, non-operated knees served as controls. At 3months postkilling, all animals were submitted to magnetic resonance imaging and biomechanical and histological evaluation. No surgery-related complications were observed. Postoperatively, all animals regularly used the operated leg with full weight bearing and no lameness. At the time of killing, all animals exhibited radiological and histological healing of the transacted ACL. Biomechanical tests confirmed successful restoration of anteroposterior translation in the dynamic intraligamentary stabilization knees. Histological examination revealed dense scar tissue at the ends of the transected ligaments exhibiting hypercellularity and hypervascularization. The dynamic intraligamentary stabilization technique successfully induced self-healing of ruptured ACL in a sheep model. Knee joints remained stable during the healing period allowing free range of motion and full weight bearing, and no signs of osteoarthritis or other intraarticular damage in the follow up were observed.