Anterior cruciate ligament suture in comparison with plasty. A 5-year follow-up study

Repair versus reconstruction for proximal anterior cruciate ligament tears: a study protocol for a prospective multicenter randomized controlled trial

Background

For active patients with a tear of the anterior cruciate ligament (ACL) who would like to return to active level of sports, the current surgical gold standard is reconstruction of the ACL. Recently, there has been renewed interest in repairing the ACL in selected patients with a proximally torn ligament. Repair of the ligament has (potential) advantages over reconstruction of the ligament such as decreased surgical morbidity, faster return of range of motion, and potentially decreased awareness of the knee. Studies comparing both treatments in a prospective randomized method are currently lacking.

Methods

This study is a multicenter prospective block randomized controlled trial. A total of 74 patients with acute proximal isolated ACL tears will be assigned in a 1:1 allocation ratio to either (I) ACL repair using cortical button fixation and additional suture augmentation or (II) ACL reconstruction using an all-inside autologous hamstring graft technique. The primary objective is to assess if ACL repair is non-inferior to ACL reconstruction regarding the subjective International Knee Documentation Committee (IKDC) score at two-years postoperatively. The secondary objectives are to assess if ACL repair is non-inferior with regards to (I) other patient-reported outcomes measures (i.e. Knee Injury and Osteoarthritis Outcome Score, Lysholm score, Forgotten Joint Score, patient satisfaction and pain), (II) objective outcome measures (i.e. failure of repair or graft defined as rerupture or symptomatic instability, reoperation, contralateral injury, and stability using the objective IKDC score and Rollimeter/KT-2000), (III) return to sports assessed by Tegner activity score and the ACL-Return to Sports Index at two-year follow-up, and (IV) long-term osteoarthritis at 10-year follow-up.

Discussion

Over the last decade there has been a resurgence of interest in repair of proximally torn ACLs. Several cohort studies have shown encouraging short-term and mid-term results using these techniques, but prospective randomized studies are lacking. Therefore, this randomized controlled trial has been designed to assess whether ACL repair is at least equivalent to the current gold standard of ACL reconstruction in both subjective and objective outcome scores.

Trial registration

Registered at Netherlands Trial Register (NL9072) on 25th of November 2020.

Clinical and radiological results after Internal Brace suture versus the all-inside reconstruction technique in anterior cruciate ligament tears 12 to 18 months after index surgery

BACKGROUND

 Anterior cruciate ligament (ACL) injury can lead to reduced function, meniscal lesions, and early joint degeneration. Preservation of a torn ACL using the Internal Brace technique might re-establish normal knee kinematics, avoid donor-site morbidity due to tendon harvesting, and potentially maintain proprioception of the knee.

METHODS

 Fifty subjects were recruited for this study between December 2015 and October 2016. Two groups of individuals who sustained a unilateral ACL rupture were included: those who underwent surgery with preservation of the injured ACL (Internal Brace technique; IB) and those who underwent ACL reconstruction using a hamstring tendon graft (all-inside technique; AI). Subjective self-administered scores were used: the German version of the IKDC Subjective Knee Form (International Knee Documentation Committee), the German version of the WOMAC (Western Ontario and McMaster Universities Arthritis Index), SF-36 (short form), the German version of the KOOS (Knee Osteoarthritis Outcome Score), and the German version of themodified Lysholm Score by Lysholm and Gillquist. Anterior tibial translation was assessed using the KT-1000 Arthrometer (KT-1000 Knee Ligament Arthrometer, MEDmetric Corp., San Diego, CA, USA). Magnetic resonance evaluation was performed in all cases.

RESULTS

 Twenty-three subjects (46 %) were men, and the mean age was 34.7 years. The objective IKDC scores were "normal" in 15 and 14 patients, "nearly normal" in 11 and 7 patients, and "abnormal" in 1 and 2 patients, in the IB and AI groups, respectively. KT-1000 assessment showed a sideto-side difference of more than 3 mm on maximum manual testing in 11 (44 %) and 6 subjects (28.6 %) in the IB and AI groups, respectively. In the postoperative MRI, 20 (74 %) and 22 subjects (96 %) in the IB and AI groups had an intact ACL. Anterior tibial translation was significantly higher in the IB group compared with the AI group in the manual maximum test.

CONCLUSIONS

 Preservation of the native ACL with the Internal Brace primary repair technique can achieve comparable results to ACL reconstruction using Hamstring autografts over a short term. Clinically relevant limitations such as a higher incidence of pathologic laxity, with patients more prone to pivot-shift phenomenon were observed during the study period.

Probing polydopamine adhesion to protein and polymer films: microscopic and spectroscopic evaluation

Polydopamine has been found to be a biocompatible polymer capable of supporting cell growth and attachment, and to have antibacterial and antifouling properties. Together with its ease of manufacture and application, it ought to make an ideal biomaterial and function well as a coating for implants. In this paper, atomic force microscope was used to measure the adhesive forces between polymer-, protein- or polydopamine-coated surfaces and a silicon nitride or polydopamine-functionalised probes. Surfaces were further characterised by contact angle goniometry, and solutions by circular dichroism. Polydopamine was further characterised with infrared spectroscopy and Raman spectroscopy. It was found that polydopamine functionalisation of the atomic force microscope probe significantly reduced adhesion to all tested surfaces. For example, adhesion to mica fell from 0.27 ± 0.7 to 0.05 ± 0.01 nN nm-1. The results suggest that polydopamine coatings are suitable to be used for a variety of biomedical applications.

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

Background

In 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.

Methods

Acute 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.

Results

278 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.

Conclusions

Anatomical 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.

Dynamic intraligamentary stabilization: novel technique for preserving the ruptured ACL

PURPOSE

Replacement 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.

METHODS

Ten 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.

RESULTS

One 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.

CONCLUSIONS

DIS 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 EVIDENCE

Case series with no comparison group, Level IV.

Isolation and characterization of multipotent stem cells from human cruciate ligaments

OBJECTIVES

Mesenchymal stem cells have great potential for tissue regeneration, and these cells can be harvested from a variety of tissues; however, up to now it has not been clear whether stem cells could be isolated from cruciate ligaments of the knee joint. The aim of our study was to isolate and characterize stem cells from both anterior and posterior cruciate ligaments (ACL and PCL) of humans.

MATERIALS AND METHODS

Cruciate ligaments were obtained from patients receiving total knee arthroplasty for advanced osteoarthritis and plastic-adherent cells were serially passaged. In vitro chondrogenic, osteogenic and adipogenic abilities of the cells were evaluated by reverse transcriptase-polymerase chain reaction and histological study. Karyotyping and surface immunophenotyping of the cells were performed.

RESULTS

It was found that a population of ligament-derived cells could be expanded and subcultured extensively. These cells were able to differentiate into osteoblasts, chondrocytes and adipocytes under appropriate inductions. Their phenotypic characteristics were similar to those of bone marrow mesenchymal stem cells. Karyotyping was normal after serial passage.

CONCLUSIONS

In summary, our study demonstrates that human multipotent stem cells can be isolated and expanded from human ACL and PCL, which are easily obtained from patients following total knee or cruciate ligament reconstructive surgery. Self-renewal and mesodermal differentiation potential of these cells make them a viable alternative source for use in regenerative medicine.

Arthroscopic single-stranded semitendinosus tendon- versus PDS-augmentation of reinserted acute femoral anterior cruciate ligament tears: 7 year follow-up study

This study reviews the long-term results of acute complete femoral tears or combined femoral (2/3 of the ligament diameter) /interstitial tears of the anterior cruciate ligament (ACL) that were reinserted. Out of 27 patients, 11 were treated with reinsertion plus augmentation with single-stranded semitendinosus tendon, 16 patients had a reinsertion and augmentation with a double-stranded PDS-band. Operation was carried out 10 (2-42) days after trauma. A brace was applied for 12 weeks, full weight bearing was allowed after 6 weeks according to our standard rehabilitation protocol. Twenty two patients (81%) could be reevaluated after a mean follow-up time of 7 years 1 month (range 3 years 8 months -11 years 5 months). No statistically significant difference was found between both techniques concerning patient's satisfaction and subjective evaluation of knee function, OAK-scores (semitendinosus-augmentation: 96 point, SD 2.0 PDS-augmentation: 94 points, SD 5.1) and IKDC-scores. Only in the PDS-augmentation group a statistically significant decrease was found in the level of activity in sports (P=0.046). At follow-up, radiological evaluation of the anterior drawer test was performed. In the group of patients who had undergone semitendinosus augmentation (n=9), anterior displacement of the tibia (determined radiologically using the TELOS-device) of 0-2 mm was found in five patients, displacement of 3-5 mm was seen in three cases and displacement of 6-10 mm in one patient (average 2.7 mm). Patients treated with PDS-augmentation (n=13) showed anterior tibial displacement of 0-2 mm in five cases, 3-5 mm in five cases, and 6-10 mm in two knees (average 3.6 mm). One patient of this group underwent ACL-reconstruction 6 years after reinsertion because of recurrent instability. At follow up, flexion was limited to less than 135 degrees in three patients (12.5%). One patient who had undergone semitendinosus augmentation and three patients from the PDS-augmentation group developed a cyclops syndrome and intraarticular adhesions that were treated arthroscopically 6 to 18 month after reinsertion surgery. A tendency towards a higher rate of limitation in range of motion was found for the PDS augmentation group. The reinsertion of a femoral torn ACL plus augmentation with a single strand of semitendinosus tendon or a PDS-band leads to acceptable results, an aggressive rehabilitation protocol may help to decrease the rate of limitation of flexion.

Tensile properties and biological response of poly(L-lactic acid) felt graft: an experimental trial for rotator-cuff reconstruction

Poly(L-lactic acid) felt (PLLA felt) was prepared for reconstruction of the rotator cuff in animal models. Small changes were found in the tensile strength of both the cultured PLLA felt and the PLLA felt implanted on the paravertebral muscle of rabbits up to 16 postoperative weeks. The stiffness of the felt implanted on the muscle from 6 to 16 weeks showed a statistically significant increase. When the infraspinatus tendons of beagle dog were reconstructed with the PLLA felt, the ultimate strength of PLLA felt increased threefold, and the stiffness increased fivefold by 16 postoperative weeks compared to that of the initial PLLA felt. They were statistically significant (p < 0.01). All the implanted specimens ruptured at the junction between the bone and the PLLA felt. Histological examination demonstrated infiltration of fibrous tissue into the interstices of the PLLA felt fibers. Connection between the infraspinatus tendon and the PLLA felt was tight with the formed scar tissue, but the connective tissue between the bone and PLLA felt fibers was sparse even at 16 and 32 postoperative weeks. A few deteriorated PLLA felt fibers were observed at 32 postoperative weeks. It was concluded that the degradation rate of PLLA felt was low and the tensile recovery of the PLLA felt graft in beagle dogs was excellent. Thus, PLLA felt might be a useful bioabsorbable material for rotator-cuff reconstruction.

Augmentation in anterior cruciate ligament reconstruction-a histological and biomechanical study on goats

We studied reconstruction of the anterior cruciate ligament (ACL) in skeletally mature goats. In one group, the autogenous tissue was augmented with polydioxanone (PDS), the other group had no augmentation. Histological complete incorporation and remodeling of the transplant was found in both groups. The newly formed connective tissues gradually assumed the microscopic properties of the normal ligament. The augmented group showed a delay in remodeling and maturation of the fiber bundles. Mechanically, the PDS-augmented transplants were stronger than the nonaugmented transplants immediately after surgery. During the first 6 weeks, a rapid decrease in strength of the augmented transplants was found, whereas the strength of the nonaugmented group gradually increased. The results of our experiment do not favor augmentation of autografts in reconstruction of the ACL.

Resorbable polymer fibers for ligament augmentation

Resorbable augmentation devices for cruciate ligament surgery have been developed to temporarily protect healing tendon grafts or sutured ligaments against high tensile loads during the postoperative healing period. Materials available at present [e.g., polydioxanone (PDS)] show a half-life tensile strength of only 4-6 weeks, whereas the process of revitalization and recovering of the transplanted tendon graft can take up to 12 months. Therefore, a device that provides gradually decreasing mechanical properties with a half-time strength of at least 6 months would be desirable. In order to obtain a suitable material, we investigated the degradation kinetics of a variety of different resorbable fibers made of poly(L-lactide) and poly(L-lactide-co-glycolide). The fiber materials differed in processing and treatment parameters like thermal posttreatment, irradiation, and fiber diameter. The fibers were degraded in vitro and were tested for mechanical properties and molecular weight at various time points up to 72 weeks. The half-time strength of the materials ranged between 5 and 64 weeks, depending on their treatment parameters. In contrast, the stiffness did not decrease adequately. However, an augmentation stiffness that does not change much versus time could not provide a gradual increase in graft load, which is important to stimulate the orientation of the collagenous tissue. Therefore, design of an augmentation construct braided out of more than one quickly degrading fiber materials is suggested. After the breakdown of the faster-degrading fiber components the stiffness would automatically decrease by the diminution of the load-carrying fiber volume.