[The S2k guideline: Indications for knee endoprosthesis : Evidence and consent-based indications for total knee arthroplasty]. / S2k-Leitlinie: Indikation Knieendoprothese : Evidenz- und konsensbasierte Indikationsstellung in der Knie-Endoprothetik (EKIT-Knie).

Total knee arthroplasty (TKA) is one of the most frequent surgical procedures in orthopaedic surgery. Until now there have not been any standardized indication criteria, which might contribute to the large geographical differences in the frequency of TKA. This guideline aims to consent minimal requirements (main criteria), additional important aspects (minor criteria), as well as relative and absolute contraindications for TKA. The following main criteria have been consented: knee pain, radiological confirmation of osteoarthritis or osteonecrosis, inadequate response to conservative treatment, adverse impact of knee disease on the patient's quality of life and the burden of suffering due to the knee disease. Relative contraindications have been consented as severe general disease with reduced life expectancy and a BMI ≥40; absolute contraindications are an active infection and if the patient is not able to undergo major surgery.

[Non-dislocated osteoporotic insufficiency fracture of the medial femoral neck. SPECT/CT makes the diagnostic difference]. / Undislozierte osteoporotische Insuffizienzfraktur des medialen Schenkelhalses. SPECT/CT macht den diagnostischen Unterschied.

Osteoporotic fragility fractures of the femoral neck are the most common type of fractures in the elderly and are associated with a high mortality. Most frequently these fractures are due to falls but spontaneous onset has also been described. In these patients the insufficient quantity and quality of the osteoporotic bone finally leads to the development of a fragility or insufficiency fracture. In some cases of nondisplaced insufficiency fractures the diagnosis cannot be established by conventional radiographs alone and magnetic resonance imaging (MRI), single proton emission computed tomography (SPECT) or SPECT/CT are considered as diagnostic adjuncts. We report the case of an 83-year-old patient who had complained of ongoing weight-bearing pelvic pain for over 6 months. There was no history of trauma. The clinical conventional radiographs as well as CT could not elucidate the cause of the problems. To differentiate between lumbal and hip pain a SPECT/CT was performed and the diagnosis of a medial femoral neck insufficiency fracture was established. In the delayed phase a band-like increased tracer uptake within the medial femoral neck was observed. The SPECT/CT procedure is a promising diagnostic alternative for geriatric patients and can be particularly recommended in cases of persistent unclear pelvic or lumbar spine pain in the elderly.

Effect of ibandronate on spontaneous osteonecrosis of the knee: a randomized, double-blind, placebo-controlled trial.

UNLABELLED: Based on this double-blind, placebo-controlled study, ibandronate has no beneficial effect on clinical and radiological outcome in patients with spontaneous osteonecrosis of the knee over and above anti-inflammatory medication. INTRODUCTION: Observational studies suggest beneficial effects of bisphosphonates in spontaneous osteonecrosis (ON) of the knee. We investigated whether ibandronate would improve clinical and radiological outcome in newly diagnosed ON. METHODS: In this randomized, double-blind, placebo-controlled trial, 30 patients (mean age, 57.3 ± 10.7 years) with ON of the knee were assigned to receive either ibandronate (cumulative dose, 13.5 mg) or placebo intravenously (divided into five doses 12 weeks). All subjects received additional treatment with oral diclofenac (70 mg) and supplementation with calcium carbonate (500 mg) and vitamin D (400 IU) to be taken daily for 12 weeks. Patients were followed for 48 weeks. The primary outcome was the change in pain score after 12 weeks. Secondary endpoints included changes in pain score, mobility, and radiological outcome (MRI) after 48 weeks. RESULTS: At baseline, both treatment groups (IBN, n = 14; placebo, n = 16) were comparable in relation to pain score and radiological grading (bone marrow edema, ON). After 12 weeks, mean pain score was reduced in both ibandronate- (mean change, -2.98; 95% CI, -4.34 to -1.62) and placebo- (-3.59; 95% CI, -5.07 to -2.12) treated subjects (between-group comparison adjusted for age, sex, and osteonecrosis type, p = ns). Except for significant decrease in bone resorption marker (CTX) in ibandronate-treated subjects (p < 0.01), adjusted mean changes in all functional and radiological outcome measures were comparable between treatment groups after 24 and 48 weeks. CONCLUSIONS: In patients with spontaneous osteonecrosis of the knee, bisphosphonate treatment (i.e., IV ibandronate) has no beneficial effect over and above anti-inflammatory medication.

One-year clinical and MR imaging outcome after partial meniscal replacement in stabilized knees using a collagen meniscus implant.

PURPOSE: The purpose of the study was to evaluate the clinical and radiological outcomes after medial/lateral collagen meniscus substitution (CMI) at 12 months postoperatively. METHODS: Sixty-seven patients (m:f = 47:20, mean age 36 ± 10 years) underwent arthroscopic CMI after previous subtotal medial (n = 55) or lateral meniscectomy (n = 12) due to persistent joint line pain (n = 25) or to prophylactic reasons (n = 42). Clinical follow-up consisted of IKDC score, Tegner score, Lysholm score, and visual analog scale for pain and satisfaction (preinjury, preoperatively, and 12 months postoperatively; follow-up rate 90 %). MRI scans were analyzed according to the Genovese criteria. RESULTS: Nineteen patients (29 %) showed a normal (A), 35 nearly normal (B), 5 abnormal (C), and 1 patient severely abnormal total IKDC score (D). The median Tegner preinjury score was 7 (range 2-10) and at follow-up 6 (range 2-10). The mean Lysholm score before surgery was 68 ± 20 and 93 ± 9 at follow-up. Preoperatively, the mean VAS pain was 4.4 ± 3.1 and 2.0 ± 1.0 at follow-up. Clinical failure of the CMI occurred in 3 patients (n = 1 infection, n = 1 failure of the implant, n = 1 chronic synovitis). On MRI, the CMI was completely resorbed in 3 patients (5 %), partially resorbed in 55 (92 %), and entirely preserved in 3 (5 %) patients. In 5 patients (8 %) the CMI was isointense, in 54 (90 %) slightly and 1 (2 %) highly hyperintense. 43 (72 %) patients showed an extrusion of the CMI implant of more than 3 mm. CONCLUSIONS: Significant pain relief and functional improvement throughout all scores at 1 year was noted. The CMI undergoes significant remodeling, degradation, resorption, and extrusion in most of the patients. No difference in outcomes between the medial and lateral CMI was observed. LEVEL OF EVIDENCE: Prospective therapeutic study, Level IV.

The position and orientation of total knee replacement components: a comparison of conventional radiographs, transverse 2D-CT slices and 3D-CT reconstruction.

We studied the intra- and interobserver reliability of measurements of the position of the components after total knee replacement (TKR) using a combination of radiographs and axial two-dimensional (2D) and three-dimensional (3D) reconstructed CT images to identify which method is best for this purpose. A total of 30 knees after primary TKR were assessed by two independent observers (an orthopaedic surgeon and a radiologist) using radiographs and CT scans. Plain radiographs were highly reliable at measuring the tibial slope, but showed wide variability for all other measurements; 2D-CT also showed wide variability. 3D-CT was highly reliable, even when measuring rotation of the femoral components, and significantly better than 2D-CT. Interobserver variability in the measurements on radiographs were good (intraclass correlation coefficient (ICC) 0.65 to 0.82), but rotational measurements on 2D-CT were poor (ICC 0.29). On 3D-CT they were near perfect (ICC 0.89 to 0.99), and significantly more reliable than 2D-CT (p < 0.001). 3D-reconstructed images are sufficiently reliable to enable reporting of the position and orientation of the components. Rotational measurements in particular should be performed on 3D-reconstructed CT images. When faced with a poorly functioning TKR with concerns over component positioning, we recommend 3D-CT as the investigation of choice.

Kinematical and EMG-classifications of a fencing attack.

8 expert fencers were studied with a 3-dimensional motion analysis system. Each subject performed 10 flèche attacks toward a standardized target. Surface electromyography signals (EMG) were recorded of the deltoid pars clavicularis, infraspinatus and triceps brachii caput laterale muscles of the weapon arm. The recorded EMGs were averaged using EMG wavelet-transformation software. 4 phases were defined based on the arm kinematics and used to classify fencers into 2 groups. A first group of 4 fencers showed an early maximal elbow extension (Early MEE) whereas the second group presented a late maximal elbow extension (Late MEE). 2 EMG-classifications were based on this kinematical classification, one in the time-domain and the other in the frequency-domain by using the spherical classification. The time-domain EMG-classification showed a significantly ( P=0.03) higher normalized deltoid intensity for the Early MEE group (91 ± 18%) than the Late MEE group (36 ± 13%) in the attack phase. The spherical classification revealed that the activity of all the muscles was significantly classified (recognition rate 75%, P=0.04) between the 2 groups. This study of EMG and kinematics of the weapon upper limb in fencing proposes several classifications, which implies a relationship between kinematic strategies, muscular activations and fencing success.

[Fixed posterior sag position after ACL reconstruction for an apparently "isolated" ACL tear]. / Fixierte hintere Schublade nach VKB-Ersatzplastik bei scheinbar "isolierter" vorderer VKB-Ruptur.

We present the case of a paraglider who suffered a valgus external rotation hyperextension injury of the right knee. The incomplete diagnosis of an isolated anterior cruciate ligament (ACL) intrasubstance tear was made and a reconstruction of the ACL with semitendinosus autograft was performed. The associated lesion of the posterior cruciate ligament (PCL) was overlooked and thus the ACL was fixed in a posterior sag position. This led to activity-related pain without any instability. The patient underwent revision surgery with débridement of the ACL and reconstruction of the PCL with quadriceps tendon.

Weak effect of metal type and ica genes on staphylococcal infection of titanium and stainless steel implants.

Currently, ica is considered to be the major operon responsible for staphylococcal biofilm. The effect of biofilm on susceptibility to staphylococcal infection of different implant materials in vivo is unclear. The interaction of ica-positive (wild-type (WT)) and ica-negative (ica(-)) Staphylococcus aureus and Staphylococcus epidermidis strains with titanium and both smooth and rough stainless steel surfaces was studied by scanning electron microscopy in vitro and in a mouse tissue cage model during 2 weeks following perioperative or postoperative inoculation in vivo. In vitro, WT S. epidermidis adhered equally and more strongly than did WT S. aureus to all materials. Both WT strains, but not ica(-) strains, showed multilayered biofilm. In vivo, 300 CFUs of WT and ica(-)S. aureus led, in all metal cages, to an infection with a high level of planktonic CFUs and only 0.89% adherent CFUs after 8 days. In contrast, 10(6) CFUs of the WT and ica(-) strains were required for postoperative infection with S. epidermidis. In all metal types, planktonic numbers of S. epidermidis dropped to <100 WT, and adherent CFUs were low in WT-infected cages and absent in ica(-)-infected cages after 14 days. Perioperative S. epidermidis inoculation resulted in slower clearance than postoperative inoculation, and in titanium cages adherent WT bacteria survived in higher numbers than ica(-) bacteria. In conclusion, the metal played a minor role in susceptibility to and persistence of staphylococcal infection; the presence of ica genes had a strong effect on biofilm in vitro and a weak effect in vivo; and S. epidermidis was more pathogenic when introduced during implantation than after implantation.

Comparison of sagittal and frontal plane alignment after open- and closed-wedge osteotomy: a matched-pair analysis.

High tibial osteotomy (HTO) is a procedure for treating medial compartment osteoarthritis (OA) of the varus deformed knee. Frontal and sagittal alignment after closed- and open-wedge HTO were compared radiologically in a matched-pair study. The mean intra-operative frontal plane correction (FT axis) was +7.5 degrees for closed-wedge HTO and +8 degrees for open-wedge HTO; it increased by +0.5 degrees in closed-wedge HTO and decreased by -0.5 degrees in open-wedge HTO at last follow-up. Post-operatively, tibial slope had decreased by -0.5 degrees in closed-wedge HTO and increased significantly by +3 degrees in open-wedge HTO. Both techniques effectively and safely corrected varus deformity. A high degree of stability of the frontal plane correction was noted, however a significant change in the tibial slope after open-wedge HTO was observed post-operatively. As no loss of correction was shown, it may be related to the surgical technique rather than to the implant used.

The use of computer-assisted orthopedic surgery for total knee replacement in daily practice: a survey among ESSKA/SGO-SSO members.

Computer-assisted orthopedic surgery (CAOS) for total knee arthroplasty is an emerging surgical tool, yet little is known about how it is being used in everyday orthopedic centers. We sought to better understand physicians' current practices and beliefs on this topic through performing a Web-based survey. Between December 2006 and January 2007, a 24-question survey was emailed to 3,330 members of the European Society of Sports Traumatology Knee Surgery and Arthroscopy (ESSKA) and the Swiss Orthopedic Society (SGO-SSO), with 389 (11.7%) agreeing to participate. Of this group, 202 (51.9%) reported that their center was equipped with a navigation system, which was an image-free based system for most (83.2%) and was primarily used for total knee arthroplasty (61.4%). In terms of the proportion of use, 50.5% of respondents used their navigation system in less than 25% of cases, 16.3% in 25-50% of cases, 7.4% in 51-75% of cases, and 25.7% in more than 75% of cases. The potential for improving the alignment of prosthesis was the most strongly cited reason for using a navigation system, while the potential for increasing operation times and the risk of infections were the most strongly cited reasons for not using a navigation system. Approximately half of respondents surveyed believed navigation systems were a real innovation contributing to the improvement of total knee implantation. However, heavy usage of computer-assisted navigation (> or =51% of cases) was observed in only 33.1% of respondents, with only a quarter using it at rates that could be considered frequent (>75% of cases). Forty-eight percent of respondents said they will use a navigation system in more cases and 39.1% that their usage will stay the same. These findings indicate that CAOS is being used only moderately in current practices, though respondents generally had a positive opinion of its potential benefits. Physicians may be awaiting more data before adopting the use of these systems, though survey responses also suggest a projected increase in their use in the coming years.

Multicenter-study of operative treatment of intraligamentous tears of the anterior cruciate ligament in children and adolescents: comparison of four different techniques.

Tears of the anterior cruciate ligament in skeletally immature patients were operated with four different methods and their outcome compared to each other. Sixty-eight patients (33 males, 35 females), mean 12.5 years, were treated in four different centers from 1984 to 2001. Twenty-eight patients underwent the ACL-reconstruction with hamstring grafts, 16 patients with bone-patella-bone autografts, 12 patients with quadriceps grafts and 12 patients with facia lata. The mean follow-up was 32 months. Postoperative evaluation included radiographs, KT-1000/2000 stability measurements, Lysholm score, The Tegner activity scale and IKDC score. Neither leg length discrepancy nor angular deformities were noted. Mean KT-1000 difference was 2.1 mm, mean postoperative Lysholm knee score 93.3, IKDC 87% normal or nearly normal. The Tegner index decreased from 6.6 to 5.7. In total, six patients developed instability due to an adequate trauma 1 year after the index operation. Two patients showed mild arthrotic changes. All but two patients were able to return to the same level of preoperative sports participation. None of the four methods studied showed major differences in outcome compared to the other. No growth disturbance could be noted.

Pulsatile dynamic stiffness of cartilage-like materials and use of agarose gels to validate mechanical methods and models.

Stiffness is a fundamental indicator of the functional state of articular cartilage. Reported test modes include compressive incremental strain to determine the equilibrium modulus, and sinusoidal strain to determine the dynamic modulus and stress/strain loss angle. Here, initial development is described for a method recognizing that gait is pulsatile. Agarose gels have been used by others for validation or comparison of mechanical test methods and models for cartilage and proteoglycan aggregate. Accordingly, gels ranging from 0.5 to 20% agarose were prepared. Pulsatile stiffness in both indentation and unconfined compression were closely reproducible. Stiffness as a function of agarose concentration rose exponentially, as found using other methods. Indentation stiffness was higher than for unconfined compression and ranged from approximately 2.0 kPa for 0.5% gel to approximately 3,800 kPa for 20% gel. Pulsatile dynamic stiffness appears to be a useful method, although further development is needed. Agarose gel stiffness values obtained by other methods were reviewed for comparison. Unfortunately, reported values for a given agarose concentration ranged widely (e.g. fourfold) even when test methods were similar. Causes appear to include differences in molecular weight and gel preparation time-temperature regimens. Also, agarose is hygroscopic, leading to unintended variations in gel composition. Agarose gels are problematic materials for validation or comparison of cartilage mechanical test methods and models.

[Analysis of wavelet transformed electromyographic signals that were altered by wearing a knee brace]. / Analyse der Veränderungen von Wavelet-transformierten elektromyographischen Signalen, wie sie beim Tragen einer Kniebandage entstehen.

The comparison of electromyograms represents a challenge for data analysis. The aim of the project was to present a method that uses a minimal computational effort to resolve small but significant changes in the muscular activity that occur while walking with and without a knee brace. The wavelet transformed electromyograms were represented as intensity patterns that resolve the power of the signal in time and frequency. The intensity pattern of each electromyogram defines single points in a pattern space. The distance between these points in pattern space were used to detect and show the separation between the groups of electromyograms that were recorded while walking with and without a knee brace. The method proposes a distance versus angle representation to visually discriminate the intensity patterns. Once it has been shown that the differences are statistically significant, one can visualize the result in a difference intensity pattern that indicates at what time and at what frequency the electromyograms vary between the two conditions tested. It is to be expected that interventions that are more intrusive than a knee brace will reveal even more distinct differences.

[Preliminary results after multiple knee injuries with operative reconstruction of chronic posterior-lateral instabilities]. / Erste Ergebnisse einer neuen Technik zur Rekonstruktion des hinteren Kreuzbandes bei komplexen chronischen Knieverletzungen.

AIM: The operative treatment of posterior knee instability is a difficult problem and the literature does not offer methods as good as ACL reconstruction. METHODS: With a new operative approach the authors have attempted to improve the surgical procedure and the final outcome in terms of stability and function. To illustrate our clinical findings, 20 cases of chronic posterior-lateral knee instability were retrospectively reviewed following PCL reconstruction. We examined 5 women and 15 men. The average follow-up period was 14 months (6 - 24 months) and the average age was 30 (17 - 59) years. RESULTS: Subjectively all patients were satisfied with the surgical outcome and there were no intraoperative technical difficulties and no patient had a postoperative problem. The p.-a. instability measured at 20 degrees of knee flexion was preoperatively 11.7 mm, postoperatively 7.2 mm and 6.7 mm on the uninjured side. The Lysholm score was preoperatively 59 (35 - 71) points and postoperatively 85 (65 - 100) points. 19 patients returned to work and 14 patients were able to participate in sports. CONCLUSION: The results demonstrate that the knee still does not have a normal stability postoperatively, but the results were reproducible and the method appears to be reliable.

[Bore canal site in surgical reconstruction of the anterior cruciate ligament. Position--placement errors--anatomic measurement]. / Bohrkanallokalisation in der operativen Rekonstruktion des vorderen Kreuzbandes. Position--Fehlplatzierung--Anatomometrie.

The goal of surgical reconstruction of the anterior cruciate ligament (ACL) is restoration of its function as closely as possible to a physiological roll-and-glide mechanism. Clinical success means knee joint stability, physiological joint biomechanics, and full range of motion. Anatomical placement of the graft insertion points and anatomical direction of the drilled tunnels are necessary to obtain isometric (anatometric) conditions. Despite technical advances in (arthroscopic) surgery, it is not yet possible to obtain absolute "isometricity" for ACL grafts. However a "physiological" or "relative" isometricity seems to be sufficient for successful clinical results. In 1986 Werner Müller proposed the term "anatometrics" in ACL reconstruction to describe this graft behavior and function. The knee joint is a complex motion system including many active and passive stabilizing elements (ligaments, tendons, muscles) as well as a proprioceptive function of the central column ligaments. Reconstruction of this "system" required the surgeon to have good surgical skills and a well-based knowledge of knee anatomy and function. Wrong placement of insertion points and bone tunnels carry the risk for ensuing graft insufficiency and resultant joint instability. The knee "prefers" a destroyed graft over an overconstrained biomechanical situation! Intraoperative factors for failure may be technical mistakes and intraoperative measuring devices for isometry, which might not guarantee true relations in a ligamentous deficient knee. Therefore, visualization of insertion points (and drilling) under direct arthroscopic view is still preferred over generalized rules and distances as proposed by many commercially available rulers and tapers. Recently, navigation and computer-assisted placement techniques have been developed. The clinical standards of those techniques are still under investigation. At our institution, an arthroscopic approach (visualization, palpation) for ACL reconstruction with a bone-patellar-tendon-bone graft technique is used.

[Validation of the Tekscan system for statistic and dynamic pressure measurements of the human femorotibial joint]. / Die Validierung des Tekscan-Systems für statische und dynamische Druckmessungen am humanen Femorotibialgelenk.

In vitro dynamic pressure measurements in the healthy and pathologically altered knee joint help to improve our understanding of the loading pattern on femorotibial surfaces. The aim of the study was to evaluate a piezoresistive pressure measuring system. A human cadaveric knee was mounted in a material-testing machine (Bionix 858) using a specially designed knee-holding device. Axial loading of the knee, flexed at 20o, at 500 N, 1000N and 1500 N was then carried out. For the static investigations, the piezoresistive measuring system (Tekscan), was compared with the FUJI measuring system. In addition, dynamic measurements were also performed with the Tekscan System. With the exception of the lateral compartment at a load of 1500 N, no differences in maximum pressures were observed between the two systems. Nor were there any differences with regard to contact surfaces, either in the medial or lateral compartment (p > 0.05). However, the reproducibility of the data was significantly higher with the Tekscan System (p < 0.01). Dynamic pressure measurements obtained with the knee flexed 20 to 90o showed that the lateral contact area shifted from anterior to posterior, while the medial contact area remained virtually unchanged. The Tekscan System proved to be more reliable than the FUJI System, and permits simultaneous measurements in both compartments. The Tekscan System is suitable for dynamic measurement of the femorotibial joint, and permits measurements to be made under more physiological conditions.

Improperly placed anterior cruciate ligament grafts: correlation between radiological parameters and clinical results.

Despite increasing knowledge on knee biomechanics and refined operative techniques, an increasing number of patients are being seen with failed anterior cruciate ligament (ACL) reconstruction. Failure of the reconstruction and further damage to the knee are correlated with improper placement of the graft, which interferes with graft biology and biomechanical demands. Between 1994 and 1995, 63 patients with improperly placed ACL grafts were referred to our institution because of persistent knee instability and pain. A method for analysis of the femoral drill hole on radiography was developed. Before reoperation the radiograph was evaluated by our method, noting the clinical aspects according to the recommendations of the International Knee Documentation Committee (IKDC). The femoral placement of the ACL graft could easily be defined on the lateral and anteroposterior tunnel radiography. The most common error was a femoral placement anterior to the anatomical insertion of the ACL. A significant correlation (P < 0.05) was found between femoral placement of the graft in the sagittal plane and clinical results: the IKDC score declined with increasing distance of the graft from the most isometric bundle of the ACL in the anteroposterior direction.

Operative treatment of combined anterior and posterior cruciate ligament injuries in complex knee trauma: can the cruciate ligaments be preserved?

A retrospective study was performed focusing on operative treatment after combined anterior cruciate ligament (ACL)/posterior cruciate ligament (PCL) injuries. The operative treatment included the preservation of one or both cruciate ligaments. Twenty-eight patients, average age 30 years (range: 12-55 years), were evaluated 5.4 years (range: 1-14 years) postoperatively. Twenty-two operations were performed in patients with acute injuries (<30 days after trauma) and 6 operations in patients with chronic instabilities (>30 days after trauma). Both cruciate ligaments were preserved by suture or refixation in 16 patients. Suture of one and reconstruction of the other cruciate ligament with autologous tendon graft was performed in 12 cases. In addition, 61 procedures (meniscal suture/resection, medial/lateral reconstruction, tendon suture, and open reduction and internal fixation were performed. Postoperative treatment included continuous passive motion and protected weight bearing. Eleven (27% acute, 83% chronic) patients required revision (ACL/PCL reconstruction, osteotomy, and meniscal repair). At follow-up, 43% of the patients were very satisfied and 46% were satisfied. Seventy-one percent (89% preinjury) of the patients were able to maintain intensive and moderate International Knee Documentation Committee (IKDC) activity levels. The IKDC evaluation of the patients (acute %/chronic cases %) was graded for symptoms: A 39% (45/17), B 35% (27/67), C 15% (18/0), and D 11% (9/17); for range of motion: A 42% (36/67), B 42% (50/17), C 16% (14/17), and D 0%; and for ligaments: A 21% (18/17), B 33% (45/0), C 42% (32/83), and D 4% (5/0). Radiographic findings were A 18%, B 41%, and C 41%. Primary repair of acute injuries was superior to the delayed repair of chronic instabilities. Preservation of cruciate ligaments in acute combined ACL/PCL tears results in a satisfying knee function despite distinct residual ligament instability. Although suture of the cruciate ligaments in open technique is a therapeutic option in acute multiligamentous knee injuries, it is not recommended for the treatment of chronic instabilities.