The Fundamental Considerations of PCL Surgery

Wilfred Krudwig , Marienhospital Eriwitte Germany

The anatomy of the PCL with 2 separate bundles and contrary functional behavior is quite different to the ACL and  requires different considerations concerning operative reconstructions depending on the individual type of injury.

The anatomical 2 bundle reconstruction needs 2 grafts, each accompanying tear of any other ligament demands an additional one. A 4-bundle reconstruction was presented for the first time last PCL study group meeting in Columbus GA USA. The functional one bundle reconstruction requires one graft.

The operative treatment of multiple ligament tears and revisions as well seen to base on different procedures especially concerning the grafts, autogenous, allografts, synthetic grafts combinations, etc.

The actual situation and the advantages and disadvantages of different procedures are presented and discussed; the following discussion might be helpful to find common ways.

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Epidemiology of PCL lesions

K. Rube, M. Schulz, M. Strobel – Straubing Germany

            Epidemiological studies are known in patients with PCL injury. But often only a small number of patients are analyzed.

Patients

            From 1993 to 1997 we treated 316 patients with PCL ruptures.

            Male 260

            Female 56

            Age 30.7 years (min 15 yr Max 60 yr)

                        Male 30.4 Female 32.1

            Interval between trauma and first examination in Straubing 3.9 yr. (min 0 max 36 yr)

            Interval from trauma to operation 4.7 yr (min 0 max 27 yr)

            Right – 165 left – 151

Therapy

            Conservative 171 (52 waiting for operation)

            PCL reconstruction / suture 145

Trauma

            Sports         108 (34%)

            Working        29 (9.2%)

            Car accident 41 (13%)

            Dashboard    25 (7.9%)

            Motorcycle    67 (21%)

            Others           15 (15%)

Former operations in 107 patients

ACL reconstructions  46

PCL reconstructions  45

Medial menisectomy 54

Lateral menisectomy 37

Medial collateral        11

Lateral collateral         7

Associated cartilage lesions are localized mainly at the medial femoral condyle and retropatellar.  

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Femoral Landmarks for PCL Insertion

J.P. Laboureau – Dijon France

            Femoral landmarks and direction of the tunnels have been more or less neglected, each of us basing his way on his own experience. Buy we should have a reproducible and constant technique.

Entries of the tunnels

            We did cadaveric studies, placing a simple fishing lead in the center of the PCL femoral attachment insertion and then taking lateral x-rays. The center of the PCL appears to be always at 40% of a line drawn parallel to the Blumensat line and passing through the most prominent point of the posterior condyle. This point corresponds to that was described by Ogata as the isometric point.

            In acute tears the concept is to hold the tibia recentered to allow healing of the ruptured PCL in it’s initial length. One bundle is enough and should be placed at this so called isometric point. In chronic cases the physiology of both the main anterior and posterior bundle should be reproduced. Two separate bundles are necessary. When using artificial ligaments, we have to have a “limited non-isometry”. This is achieved by inserting the anterior bundle between the isometric point and Ogata’s point D and the posterior bundle between the isometric point and Ogata’s point C.

            Point E is at an average of 15 mm from the roof of the notch, 10 mm from the cartilage edge. Distance point C and D is 12 mm. These distances are smaller or bigger according to the size of the bone.

Directions of the tunnels

            To avoid any increasing of the rotational stresses in the artificial ligament during flexion and extension, as well as an important angulation during extension, we must adopt a compromised solution. The femoral tunnels must be as close to the direction of the intra-articular PCL itself when the knee is extended. Therefore they must be directed towards the anterior and medial aspect of the femoral metaphyseal cortex.

Surgical Procedures

            The isometric point E can be determined on a pre-op x-ray with the 40% rule, or during surgery with the help of an image intensifier. Because of the directions of the tunnel they cannot be easily drilled from outside in. The drilling is made from inside out.

            Because of the obliquity of the drill bits, the entrance of the tunnel on the medial wall of the notch will be oval. Therefore the posterior wall of each tunnel will be more posterior than expected. The tip of the drill bits must be very sharp and placed very close to the cartilage limit.

            Since we have used this technique, we have been improving our mechanical results. Particularly we get over 90% normal knees in acute PCL tears, which is even better than the ACL injuries, most probably because  of the vascularization and high healing potential of the PCL.

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Tensile Properties of the human PCL in depence of age and immobilization.

Dr. Jorge Petermann.

Purpose of the study

            Some investigations of the tensile properties of the human PCL have been performed, but the period of immobilization of the specimen before harvesting is not reported in any study. The amount of the specimen ranged from 3-12, and only in one study was looked whether the tensile properties of the PCL depend on the age of the patient. The aim of this study was to investigate the influence of age of the speciman and the period of immobilization  on the tensile properties of the PCL

Statement of the methods used

            In 62 cadaver knee joints tensile properties of the human PCL are described with a computer controlled material testing machine. The age of the specimen and the time of immobilization before harvesting (as soon as possible after death) was registered. The cause of death was noted. All knee joints used had no ligament instabilities, severe degenerative changes or acute ligamentous or osseous lesions. The tensile testings were performed in a special frame, the angle between the tibia and femur was 30*. The rupture speed was of 500 mm/min. The PCL was tested as a bone-tendon-bone graft in its natural insertion positions. The length, width and depth of the PCL was registered. Maximum rupture force, rupture force at break and elongation was measured. Tensile stress, tensile stress at break and modulus was calculated. The datas were analysed with the multiregressional analysis by spearman rank.

Summary of Results

            The mean age was 61.5 with range 21 to 90 years.

            The mean length was 40.7 mm, the area of the tibial insertion point 41.4 +/- 2.3 mm2 The maximum rupture force ranged from 0-3152N, the rupture force at break from 0-2756N. Tensile stress ranged from 0-103 N/mm2 and tensile stress at break point from 0-122N/mm2. The period of immobilization till harvesting was 0-9 weeks. Analysing the results we could show that the factor of immobilization weakens the PCL 4 times more than the age of the specimen measuring max rupture power (max rupture force N – 104 X immobilization in weeks + (20.7Xage in years) = 26664 N) and five times measuring the tensile stress (tensile stress (N/mm2)=2.4X immobilization in weeks+(0.48Xage in years)+62.3Nmm2) We found a linear correlation for all tested parameters.

Major Conclusions

            Immobilization leads to a quick change of tensile properties and weakens the ligament, the age has less influence. The indications for a ligament reconstruction in knee joints of older patients should respect their activity level. After the operative procedures and during rehabilitation, no immobilization should be performed. In cases of harvesting a ligament for transplantation, the period of immobilization has about a 4X higher influence of the tensile properties of the graft.

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Dynamic Stability of the Knee: Normal and ACL Deficient Subjects - N. St-Onge,  Nic Duval

Authors : N. St-Onge N. Duval, L'H Yahia, KG. Feldman.

Introduction and objective. Knee ligament injuries present an increasing annual incidence. These injuries usually occur in young, healthy, active people, The resulting instability produces an abnormal joint movement provoking pain, swelling, cartilage lesions, and early degenerative arthrosis. Tests available for knee stability evaluation whether manual or instrumented measure mechanical stability only. However, if we take into account the neurosensorial component of ligaments, evaluating only the mechanical stability of the knee might be insufficient (Duval and St-Onge, 1996). That could explain the poor correlation between the results obtained with those tests and the patients satisfaction level.

The aim of this project is thus to develop a method to evaluate tridimensional dynamical stability of the knee. Since one of the more frequent problems is the rupture of the anterior cruciate ligament, the modifications produced by this injury will be studied.

Methods. Subjects executed one-legged jumps and projections, Movements were performed vertically, forward, backward, and sideway. Projections took place on the ground and on a wobbling board. Some projections were executed from the ground to a. platform and from the platform to the ground. Movements were performed 10 times on each leg. Results obtained with normal subjects are necessary to learn about the normal difference between the legs of a given person. We can then compare the injured and the non-injured leg of ligament-deficient subjects to find out how this difference varies from that of the normal population. During those movements, we recorded kinematics of the leg. We then computed flexion/extension, internal/external rotation, adduction/abduction of the hip and knee, as well as flexion/extension and adduction abduction of the ankle. We also recorded EMG activity of the pectoralis, erector spinae, gluteus maximus, rectus fernoris, vastus medialis, biceps femoris, medial gastrocnemius, and tibialis anterior.

Results. We will present the co-ordination between the various angles and try to identify typical patterns in normal subjects. If we find such patterns, we will analyse the difference between normal and ligament-deficient patterns. We will look at EMG activity to understand compensatory muscle patterns. This might help understand how a ligament­deficient person with poor mechanical stability can improve dynamical stability.

Conclusions, ligaments offer not only mechanical but also dynamical stability to the oint. A method that evaluates tridimensional dynamical stability of the knee in an objective manner would therefore be very useful to determine the functional state of the knee of people suffering from ligament injuries. It would help in choosing the necessary treatment as well as in the follow-up of the patient. Such a method would allow the objective comparison between the existing treatments and the various types of reconstructions. The analysis of the variation between the co-ordination patterns of the normal and the ligament-injured population during the execution of dynamical movements could help the elaboration of such a method.

Reference. Duval, N. and SI.-Onge, N. 1996. in Yahia, ed., ligaments and ligamentoplasties, 19-, Springer-Verlag, Heidelberg.

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Biodegradable Interference Screws in Cruciate Ligament Surgery

- Biomechanics and Biology —

Andreas Weller, M.D.

Trauma & Reconstructive Surgery, Virchow Kilnikum, Humboldt University Berlin

The authors will present recent biomechanical results of six different biodegradable interference screws ¼ Data presented include failure load, stiffness of fixation and screw insertion torque in a model of standardized bone density in calf tibial bone. Six different screws representing six different threading and drive designs, consisting of five different biodegradable polymers were studied. Due to recent reports on screw breakage, additionally torsional failure load data will be presented.

Experimental and clinical experiences concerning degradation and biocompatibility of different biodegradable polymers proposed for implants in orthopaedic and trauma surgery will be presented. The authors will discuss demands and factors influencing biocompatibility and degradation 2,3,4

1.             Weller A, Windhagen HJ, Raschke MJ, Laumeyer A, Hoffmann REG. Biodegradable interference screw fixation exhibits similar pullout force and stiffness as compared to titanium screws. Am. J. Sports Med., 25, 1997, in press

2.             Weller A, Helling HJ, Kirch U, Zirbes TK, Rehm KE: Foreign-body reaction and the course of osteolysis after polyglycolide implants for fracture fixation - Experimental study in sheep. J. Bone Joint Surg., 78B: 369-3 76, 1996

3.             Hoffmann R, Weller A, Helling HJ, Krettek C, Rehm K.E: [Local foreign-body reactions to biodegradable implants— A classification system.] Unfallchirurg, 100, 1997, in press

4.          Staehelin AC, Weiler A, Ruftnacht H, Hoffmann R, Geissmann A, Feinstein R: Clinical degradation and biocompatibility of different bioabsorbable interference screws - A report of six cases. Arthroscopy, 13: 238-244, 1997

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Biodegradable Interference Screws in ACL and PCL Reconstruction

  - Clinical Degradation and Biocompatibility —

Andreas Staehelin, M.D.

Private Orthopaedic Practice, Basel, Switzerland

The use of biodegradable interference screws in cruciate ligament reconstruction has recently raised continuous interest which lead to a large variety of implants being available. However, these screws not only differ in design from one another but more importantly, they differ in choice of polymer material, which ultimately determines the biocompatibility and in vivo degradation behaviour. Due to several reports on foreign-body reactions to biodegradable implants in fracture fixation there are still controversies on the use of biodegradable implants in orthopaedic sports medicine.

Since November 1992 in a series of more than 400 patients five different biodegradable interference screws, consisting of four different polymers (poly-L-lactide, PLA 98, Poly-D,L-lactide, poly-D,L­lactide co glycolide) have been used for AOL or POL reconstructions 1,2· 2% of these patients underwent repeat arthroscopies unrelated to the implanted screw material at different intervalls after the index operation. Biopsies were taken at the implant site and the author will present radiological, intraoperative and histological findings.

1.  Stahelin AC, Weiler A, Rllftnacht H, Hoffmann R, Geissmann A, Feinstein R: Clinical degradation and biocompatibility of different bioabsorbable interference screws - A report of six cases. Arthroscopy, 13: 238-244, 1997

2.  Staehelin A, Feinstein R, Friedench N: Clinical experience using bioabsorbable interference screw for ACL reconstruction. Orthop Trans 19:287-288, 1995

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Measurment of Rotational Stability of the Knee and Clinical Applications

RaviKumar. R., Beacon, IF, Chatoo, M., Laboureau, J.-P. West Herts Knee Unit, Hemel Hempstead, Herts, UK

INTRODUCTION

A major part of knee stability is rotational. Our previous studies show there is a difference in stability between internal and external rotation of the tibia on the femur. The obliquity of the two cruciate ligaments and the wind-up of these during internal rotation of the tibia on the femur, provide a major component to knee stability.

The Rotational Laxiometer has been developed in the Unit over the last 10 years, in order to measure the internal and external rotation of the tibia on the femur. It is a portable, electronic goniometer which permits measurement of rotation of the tibia on the femur in any degree of knee flexion.

This paper records the arc of tibial rotation in 120 pairs of normal knees at 30 and 90 degrees of flexion. The results do not demonstrate a significant difference in the rotation arcs between each knee in a normal pair of knees. The technique of measurement using the Rotational Laxiometer and the physiological range of tibial rotation arcs are presented. The present system of instruments used to detect and assess knee laxity depends mainly on AP Glide. None of the systems measure rotational laxity which is of paramount importance.

In a knee which has received certain injuries affecting rotational stability, the change in the arc of tibial rotation can be measured. The contralateral uninjured knee can act as control. Therefore, a quantitative assessment of knee stability can be gained, by using the Rotational Laxiometer.

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Stress X-rays in diagnosis of PCL lesions

M. Strobel, K. Rulle, M. Schulz (Straubing, Germany)

Clinical diagnosis of PCL lesions is very difficult. Therefore a lot of these serious injuries are misdiagnosed or not diagnosed. The integrity of the PCL can be evaluated with MRI,  but this technique only describes the morphology of the PCL. A functional evaluation 15 given with stress-X-rays.

Patients: From 1.1.1993-30.6.1997 313 patients with isolated PCL-ruptures are treated. Male 258 / female 55.               3 patients with bilateral PCL rupture are excluded.

Results

 Stress X rays: Posterior tibial displacement (PTD) in posterior drawer test

PDT 90* flexion of the injured side - 13.9 mm (min 4 max 30mm)

lntact knee PTD (PDT 90* flexion  1.6 mm (min +2, max 4 mm) PTD in PDT 30* flexion of the injured knee 11.9 mm (min 3, max. 25 mm), intact knee 6.1 mm (min 2, max 10 mm)

Conclusions

Stress X-rays are a sufficient examination technique to show fresh and chronic PCL lesions We emphasize the PDT in 90* flexion When the PD >5 mm this is an indication for a PCL injury, especially when PD of the contralateral side is < 1 mm PTD > 10 mm is a reliable indication of a complete PCL rupture 1 insufficiency. Arthroscopic examination is not very helpful for diagnosing PCL insufficiency.

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KT-1000 Testing Technique for Identifying PCL Injury or Insufficiency

 Mary Lou Stone

Clinical application of instrumented testing in the PCL deficient knee has been problematic. Measurement technique needs to take into account limb position, starting position and external muscle forces. This paper will discuss proper testing technique with the KT-1000 and clinical results In 25 PCL-deficient patients.

With the knee in slight flexion tension through the anteriorly oriented patellar tendon results in anterior tibial translocation which is constrained by the ACL. As the knee flexes, the patellar tendon orientation in the intact knee changes from an anterior orientation to a neutral orientation to a slightly posterior orientation. A major determinant of the AlP tibial/femoral position is the interaction between the quadriceps tendon and the cruciate ligaments, ACL in slight flexion and PCL in marked flexion. In the mid arc of flexion. the quadriceps tension alone dictates the A/P joint position and neither cruciate ligament is loaded therefore the joint position is not affected by cruciate ligament integrity.

Materials and Methods: AlP joint laxity was measured with a portable knee ligament arthrometer (Medmetric KT-1000 Twenty-five patients with a unilateral PCL disruption were measured. In all subjects the active quadriceps drawer was performed at 900 of flexion. at 30* and at the active quadriceps neutral angle which was determined by the subject’s normal knee. The Active Quadriceps Neutral Angle (AQNA) is the angle in which there is no tibial translocation with a quadriceps contraction in the subject’s normal knee. In all subjects, anterior and posterior passive drawer measurements were also performed.

Results: With the knee in 90* of flex-ion the tibia was subluxated (sagged) posterior in all subjects with a PCL disruption. In all subjects the active quadriceps drawer resulted in anterior tibial translocation in the PCL deficient knee. The normal knee revealed one to two mm of posterior tibial translocation with an Active Quadriceps Drawer (AQD) test. At the AQNA by definition the AQD in the normal knee was zero. The mean AQNA was 70* with a range from 60* to 85* All PCL patients demonstrated a tibial sag at the QNA (mean 8mm, range 2 to 16.5mm).

 1) In the standard 90 drawer testing position the tibia in patients with a PCL disruption is subluxated posterior. This posterior subluxation (sag) can be diagnosed by documenting anterior tibial displacement with the active quadriceps drawer test (AQD). 2) At the active quadriceps neutral angle (AQNA) the tibial/femoral position during a quadriceps contraction is not influenced by cruciate ligament integrity an therefore may serve as a reference position. the active quadriceps neutral position (AQNP). The AQNP serves as the position from which anterior and posterior laxity may be measured.

 1) Daniel, D et al Ortho Transactions Vol 2 p 192, 1982. 2) Barnett, P et al. ORS Transactions 0 133, 1984. 3) Malcom. L et al. ORS Transactions p 253, 1982.

A video tape will be presented during the testing technique for PCL injury insufficiency with the Medmetric KT-1000

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The Biomechanical Effect of Posterior Cruciate Graft Angulation

Author William G. Raasch, M.D., Medical College of Wisconsin, Milwaukee, WI, USA

Introduction & Purpose: Posterior cruciate ligament (PCL) reconstruction has not succeeded in returning baseline laxity to the knee. The reason for the stretching of the graft has not been determined. PCL reconstruction involves significant graft angulation which may contribute to graft stretching. Angulation results in non uniform graft loading and may lead to sequential failure of the outer graft fibers and graft elongation. The purpose of this study is to determine if the biomechanical structural properties of the graft are different when loaded in angulation than longitudinally.

Materials and Methods: Six matched fresh frozen cadaveric 10mm bone-patellar-bone grafts were harvested. One of each pair was loaded longitudinally while the other in 90 degrees of angulation about a 5mm radius of curvature. Angulation and the radius of curvature were determined by digitizing photographic markers on a bisected cadaveric knee following PCL reconstruction. Grafts were loaded for 30 cycles from 100 to 500 newtons under load control. Load deformation curves (Figure 1) were obtained and subjected to statistical analysis.

Results: The average elongation over 30 cycles for the longitudinally loaded graft was 0.079 cm and for the angulated graft 0.285 cm (P=0.036). This represents a 318% difference in graft elongation. The average hysteresis over 30 cycles for the longitudinally loaded graft was 1.739 Ncm and for the angulated graft 3.478 Ncm (P0.0 19).

Conclusion: Graft angulation results in a change of the structural behavior. With angulation the graft elongates an average of 318% over the non angulated graft. This angulation may cause early failure of outer graft fibers due to non uniform loading. This may contribute ultimately to graft elongation. Reconstructive procedures which minimize graft angulation may reduce the risk of graft stretching.

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ANALYSIS OF THE INTERNAL AND EXTERNAL ROTATION ROLE OF THE POSTERIOR CRUCIATE LIGAMENT AND THE ANTERIOR CRUCIATE LIGAMENT

Beacon JP Aichroth, P.

West Hens, Knee Unit, Hemel Hempstead. UK

INTRODUCTION

The rotational bio-mechanics of the knee were studied in 6 cadaveric knees. The first study was carried out at The Westminster Hospital in 1977. In order to access the A.C.L. and P.C.L.. all other soft tissues were dissected from knee joint. Using a special jig, x-ray studies were performed and these studies were collerated with mechanical measurements using a transducer hot-wire. Different bio­mechanics were found to operate in internal rotation as opposed to external rotation.

The findings will be presented in this paper.

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Reconstruction of Acute Isolated Lesions of the Posterior Cruciate Ligament -Surgical Procedure and Follow-up Results

Petermann J, Ishaque B, Gotzen L

Department of Trauma Surgery, Philipps-University, Baldinger Strasse 

Purpose of the study: The indication for the surgical reconstruction of the acutely torn posterior cruciate ligament (PCL) is discussed controversially. Osseous avulsion fractures are always an indication for an operative procedure as nearly in every case good or excellent results with stable knee joints can be achieved. Therefore the different results of the PCL reconstruction should be caused by the method of surgery. After the experimental study to define the isometric placement of the PCL substitutes and measurement of the tensile properties we standardized our new surgical procedure. Purpose of the study was to perform a follow-up examination to compare the results of the old anatomical (group A) with the new isometric reconstruction group (group B).

Statement of methods used: The follow-up examination included the patients history, clinical examination, an instrumented measurement of the anterior-posterior translation with the KT 1000 the scoring by Lysholom, Marshall, OAK and IKDC including the measurement of muscle force by isokinetics in an angular velocity of 6o and 18o drg. / sec.

Summary of results: From 1985 to 1994 we performed PCL surgery in 38 patients with isolated lesions. 28 were male, the mean age was 3o,4 years. The follow-up included 4 of the six patients with an osseous avulsion fracture. They all got an open reduction with a screw fixation and healed stable with the best results in scoring and isokinetics. For the PCL reconstruction we standardized use a substitute taken from the central part of patellar tendon (13mm) with an augmentation (5 mm Trevira-ligament, tetra-L by telos). Only lesions close to the attachments were refixed. Patients with a PCL-refixation or reconstruction in the anatomical position (group A) showed a Lyshoim-score of 86.7, a Mar­shall-score of 38.6 and a posterior translation of 4.8 mm in the 900 position with the KT boo (follow-up 97 months). Patients (nlo) with the isometric prode­cures (group B, refixation n=5) had a Lysholm-score of 91.1, a Marshall-score of 39.8 and a posterior KT 1000 translation of 3.1 mm in the same position (follow-up period 23 months). The IKDC scoring and the isokinetic testing showed better results in group B than A.

Major conclusions: In changing the surgical procedure from the anatomical femoral tunnel placement to the isometric placement for the augmentation band or the combined PCL substitutes we could achieve better results in the knees of patients with an acute isolated PCL rupture, but the coming out of the ligamen­tous lesions was not as good as the femoral avulsion fractures treated by open reduction and screw fixation. Furthermore the groups are very small and there is a shorter time of follow-up for the group with the isometric placement.

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Direct Tendon to Bone Fixation With Interference Screws

- Biomechanics and Biology

Andreas Weller, M.D.

Trauma & Reconstructive Surgery, Virchow Kilnikum, Humboldt University Berlin

The authors will present recent biomechanical data on fixation strength of direct hamstring tendon graft fixation using biodegradable and round threaded titanium interference screws 1, 2 Additionally, preliminary data on construct elongation and slippage in young human cadaveric knees will be presented

Preliminary biomechanical and histological results of reconstructed ACLs in sheep will be demonstrated 5. 36 six animals received ACL reconstruction using direct tendon to bone fixation with biodegradable interference screws. 24 animals were evaluated after sacrifice, 6, 9,12 and 24 weeks after surgery.

1.         Weller A, Hoffmann R, Staehelin A, Bail H, Raschke M, Sudkamp NP: Semitendinosus graft fixation with bioabsorbable interference screws. Trans. Orthop. Res. Soc., 43rd Annual Meeting, San Francisco 1997

2.         Weiler A, Scheffler 5, Gockenjan A, Hoffmann R: Fixation slipage, construct elongation and failure load of anatomic, semi-anatomic and extraarticular hamstring tendon fixation techniques for ACL reconstruction under incremental cyclic loading conditions. Unpublished data

3.         Weiler A, Peine R, Pashmineh-Azar R, Hoffmann R: Biomechanics of direct tendon to bone healing under interference screw fixation in a sheep model. Unpublished data

4.         Weiler A, Bail H, Peine R, Rehm 0, Hoffmann R. Histological analysis of tendon to bone healing after ACL reconstruction using direct interference screw fixation. Unpublished data

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The Direct Tendon to Bone Fixation with Biodegradable Interference Screws

- A New Operative Technique for ACL and PCL Reconstruction —Andreas StaeheIin, M.D. Private Orthopaedic Practice, Basel, Switzerland

A modification of ACL reconstruction using minimally invasive and endoscopic all-inside technique is presented Both, the femoral and tibial socket are approached through the joint, so there is no open tibial tunnel. The autologous semitendinosus tendon is harvested with a bone plug attached from its tibial insertion site. The triple stranded semitendinosus tendon is looped around the adjacent bone plug and fixed at the original tibial attachment site of the ACL using a soft threaded biodegradable interference screw. The screw is inserted endoscopically in an inside-out direction. In the femoral socket the graft is fixed directly without bone plug to the tunnel wall.

The PCL is reconstructed with a quadrupled semitendinosus — gracilis ,,Y shaped tendon graft 2,3· In the medial femoral condyle two tunnels are created inside-out through a low anterolateral arthroscopy portal 4. First in 90 degree of flexion the double-stranded gracilis tendon graft is fixed with a biodegradable screw inside the lower femoral socket. In full extension the quadruple graft end is fixed inside the single tibial tunnel under 80 N of pretension. Finally 80 N of pretension is applied to the double-stranded semitendinosus tendon proximally and in 90 degree of flexion the second femoral interference screw is inserted. Using this technique the stronger semitendinosus part (anterolateral bundle) is fixed in 90 degree of flexion whereas the smaller gracilis tendon part (posteromedial bundle) is fixed in full extension.

1.         StaeheIin AC, Weller A: All-inside ACL reconstruction using semitendinosus tendon and soft threaded biodegradable interference screw fixation. Arthroscopy, 1997, in press 

2.         Morgan CD, Kalman VR, Grawi DM: The anatomic origin of the posterior cruciate ligament: Where is it? Reference landmarks for PCL reconstruction. Arthroscopy 13: 325-33 1, 1997

3.         Laboureau JP: The two bundle PCL reconstruction: Technique and results. In Friedman MJ ed., Allograft and Artificial Ligaments, Philadelphie: Saunders, 1995

4. Kim SJ, Mm Arthroscopic intra-articular interference screw technique of posterior cruciate ligament reconstruction: One-incision technique. Arthroscopy 10: 3 19-323, 1999t

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The Straight Medial Ligamentous Instability of the Knee Joint Surgical Procedure and Follow-up Results

Petermann J, Ishaque B, Gotzen L

Department of Trauma Surgery, Philipps-University, Baidinger Strasse

FRG-35o33-MARBURG, 3 -6421 - 286216, FAX, 6421- 286721

Introduction:    Straight ligamentous instabilities are a rare and severe injury for the knee joint. For the reconstruction of this we perform an augmented techni­que (Tetra L) using the central third of the patellar tendon of the injured and, if necessary, of the uninjured side addionationally. The lesions of medial collateral ligaments were reconstructed by an PDS-band augmented technique. Immediately postoperatively an accelerated rehabilitation program with an unlimited range of motion was performed and braces were not be used. Material and Methods: a follow-up study we looked for the patients with straight medial instabilities of the knee joint treated in our hospital at least one year after surgery. The follow-up criterion was the IKDC-score, including an isokinetic testing protocol ( 6o dig. and 180 dig. v/sec angular velocity). Results: During 1985-1995 we treated 35 patients with this rare and severe injury. The average age was 33.4 years and 28 patients were m1e The mean time after the reconstruction at the time of follow-up examination was 3,4 years. The right knee was involved in 18 cases, the medial opening was 2-s- in 5 and 3 + 3o knee joints. The mechanism of injury was mostly a high energy trauma an a traffic injury. In knee joints with a 3+ medial opening we found I femoral osseous avulsion fracture, 16 ruptures close to the femoral insertion, 9 interligamentous lesions and 4 ruptures close to the tibial attachment. In knee joints with a 2+ medial opening we found 2 interligamentous lesions, 2 ruptures close to the tibial attachments and I osseous tibial avulsion fracture. Lesions close to the attachments we treated by an augmented trans­osseous reconstruction technique, PCL reconstruction by patellar tendon substitutes were performed by interligamentous lesions. In cases with a simultaneous reconstruction of the ACL and the PCL we took the patellar tendon transplanted from the uninjured side. All patients underwent an accelerated rehabilitation program. An unlimited range of motion was allowed postoperatively and full weight bearing was allowed after the 6 week. 27 patients came to the follow-up examination The scores were 5 x A, 14 x B, 5 C, 3 x D. Problems at the knees with the harvested central third of the patellar tendon could not be found Conclusions With the described surgical procedure and the accelerated rehabilitation program we can achieve in most of the cases staple knee joints and for the patients good or satisfying results in most of these rare and severe injures.

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Fixed posterior drawer -  history, diagnosis, therapy

M. Strobel, B. Brand, K. Ruse (Straubing, Germany)

Knee injuries with cruciate lesions and no exact diagnostic evaluation are often treated with immobilization in a splint or cast with slight flexion. A PCL lesion in this patients leads to a posterior position of the tibia and slight flexion immobilization leads to healing of associated injured sublux (posterior capsule, collateral) The result is a fixed posterior position of the tibia with or without an extension deficit But there are also other reasons for this disastrous condition

Patients: In 37patients we find a posterior position of the tibia in stress X-rays for anterior drawer test ADT 90 flexion PTD with APT 6.2mm (mm 2, max 13 min) Posterior tibial displacement in PDT 90 flexion PTD  14.7 mm posterior drawer test PDT 90 (mm. 9, max. 19mm).

Former treatment: ACL reconstruction (n= 14), suture medial collateral (n = 2), ACL reconstruction and suture med. coil. (n=2), PCL reconstruction (n= 1), conservative (immobilization) or no treatment (n=18)

Therapy: Arthroscopy with resection of mechanical scars in extension deficit or after ACL reconstruction. PTS brace for 6 weeks Physiotherapy, Stress X-ray (APT 90) control every 6 weeks.

Results: Reduction of the fixed posterior drawer in 34 patients (04.1 mm).

Conclusions:   For getting good results in PCL reconstruction it is important to exclude a fixed posterior drawer of the tibia (stress X-rays ADT 90) in this patients. To avoid fixed posterior drawer it is very important to immobilize a knee without exact diagnosis in flexion and to pay attend to the arthroscopic signs of PCL insuff. (lax  ACL )

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PCL RECONSTRUCTION USING A SYNTHETIC LIGAMENT OF POLYETHYLENE-TEREPHTHALATE

(TREVIRA-LIGAMENT) 8-YEAR FOLLOW-UP

Wilfried K. Krudwig, Marienhospital Erwitte, Germany

Between 1989 and 7/1996 - 52 PCL reconstructions have been performed.

37 cases are presented and discussed. The follow-up time is 4,3 years

(1,6-8,1).

The outcomes base on a questionnaire, the clinical examination and a radiological Lachman test.

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COMBINED PCL+ACL RECONSTRUCTION USING A SYNTHETIC LIGAMENT OF POLVETHYLENE-TEREPHTIIALATE (TREVIRA-LIGAMENT)

8-YEAR FOLLOW-UP 

Wilfried K. Krudwig, Marienhospital Erwitte, Germany

Between 1989 and 7/1996 23 PCL combined reconstructions habe been performed. 17 cases are presented and discussed. The follow-up time is 5,2 years (1,8—8,3).

The outcomes base on a questionnaire, the clinical examination and a radiological Lachman test.

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Combined Posterior Cruciate Ligament Reconstruction Together With Posterolateral Tenodesis Using Four Strand Hamstring Graft 

Paul Aichroth MS FRCS, Zaid Dun MB Mch (Orth)

Wellington Knee Surgery Unit, The Wellington Hospital, London, NW8 9LE 

At the Columbus Meeting one year ago, the principle of combined posterior cruciate ligament reconstruction together with posterolateral tenodesis was established for severe Cooper grade or 3 injuries, in which there was posterolateral rotary instability. 

Over the past year, 13 patients have been so treated. In 10 patients, a combined procedure was undertaken with hamstring graft, harvested from both ipsilateral and contra-lateral sides. In a further three patients with grade Cooper lesions, in which the anterior cruciate ligament was also ruptured the reconstruction technique used allograft for the posterior cruciate ligament and hamstring grafts for the anterior cruciate ligament and posterolateral tenodesis.

Although the follow-up is short, all but one had good restoration of stability and function. The posterior cruciate ligament laxity remained less than 5 mm at 900 and the posterolateral rotary instability was reduced to less than grade 1 with completely controlled external rotation. These early results will be discussed and criticized.

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The Preliminary Results of Posterior Cruciate Ligament Reconstruction Transtibial Two Tunnel Technique vs. Tibial Inlay Technique

Young Bok Jung, M.D., Suk Ki The, ALD., Jac Kwang Yeum, M.D., Ban Ho Koc, M.D.

Department of Orthopeadic Surgery, Young San hospital,

Qwng-Ang University, Seoul, Korea

<Introduction> From 1989 to 1994, authors had arthroscopic assisted reconstructed the posterior cruciate ligament (PCL) in 51 knees with the autogenous central one-third of patellar tendon by transtibial two tunnel technique, but there were not a few cases of unfavorable results. So from 1995, we have reconstructed the PCL deficient knee by modified tibial inlay technique to avoid the graft tendon abrasion at the posterior opening of the tibial tunnel killer turn). And we have reconstructed the posterolateral instability, even though it is a mild degree, simultaneously with the PCL reconstruction by the modified tibial inlay technique. Purpose of this study was compare to the results of two surgical technique and what is its advantages and disadvantages.

<Method> We could follow up 39 cases in transtibial two tunnel technique group(group A) more than one year, average being 23.1 months and 21 cases in modified tibial inlay technique group (group B) more than 12 months, average being 14.7 months. The clinical results were analyzed by the OAK knee scoring system (Muller’s criteria) and the radiographic results were analyzed by lateral knee roentgenography and the posterior stress roentgenography with Telos stress device (push view) compared with the normal side knee. The arthroscopic second-look findings were included in analysis of the results.

In group A: The Muller’s knee sore was average 80.1 points, the position of the femoral bone block was mean 31% and the posterior displacement in push view was average 4.4mm at the last follow up. There were 17 cases (44%) of unfavorable results which showed unstable posterior displacement more than 4mm compare with the normal knee in push view. Among the

19 cases of arthroscopic second look examinations, the neatly normal PCL features of the grafted tendons were noted only in 9 cases (47%).

In group B: The Muller’s knee score was average 86.7 points, the position of the femoral bone block was mean 32% and the posterior displacement in push view was average 3.6mm at the last follow up. There were 5 cases (23.8%) of unfavorable results which showed unstable posterior displacement more than 4mm compared with the normal knee in push view but 4 out of

5 cases showed 6mm of posterior displacement in push views Among the ‘/ cases of arthroscopic second-look examinations 6 cases (86%) showed nearly normal PCL features of the grafted tendons. The combined PCL injury cases which showed  posterior instability more than 11mm in push views preoperatively had worse final results in clinically and radiographically than the isolated PCL injury cases in group

A (P<O.OI).

<Discussion & Conclusion> In modified inlay technique easier to pull out the PTB and also in cases remained meniscofemoral ligament was easier preserve it than in two tunnel technique. We think that any degree simultaneously with the PCL reconstruction. And we expect the modified tibial inlay technique may solve the problem of grafted patellar tendon abrasion at the “killer turn” and may contribute to the successful PCL reconstruction. However, further studies with many cases and long term follow up are needed, we think. Even though modified inlay technique some laxity was recurred in 17.2% of the cases. We need more develop new surgical technique and post operative rehabilitation, especially in severely unstable knee.

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The functions of the PCL 

The cruciate ligaments originated 300 million years ago, and consisted originally of 3 liga­ments, 2 anterior (medial and lateral cruciates) and I posterior (intermediate cruciate). In birds and in higher mammals, the medial cruciate disappeared. This enabled the intermediate (posterior) cruciate, originally situated in the middle of the knee, to extend to the medial femoral condyle in mammals and to the medial tibial condyle in birds. Hence the posterior cruciate ligament disposes of an oblique orientation which is responsible for the various functions. The PCL consists of 4 different fiber types: 1) one isometric bundle, 2) extension restricting fibers. 3) flexion restricting fibers, and 4) fibers which are taut in intermediate positions and which support the isometric bundle. The origin of the latter fibers within the femoral footprint is shaped like a fan, the center or area of divergence of this fan corresponds to the isometric bundle. The general doctrine in anatomical textbooks concerning the winding—up of the two cruciates leads to the explanation of the restriction of voluntary internal rotation. This, however, is not true. After having removed the collateral ligaments, the capsular ligaments, and the menisci, the shank can be internally rotated up to 90. The collateral and capsular ligaments are responsible for the restriction of internal rotation.

At the end of extension the shank performs a compulsory outward rotation, the so called automatic rotation. Three structures are responsible for this motion: 1) the ACL (it would become “too short”), 2) the curvature of the medial femoral condyle, and 3) the PCL. The first 2 structu­res are merely consequences and not causes. Would the PCL be straight in the middle of the knee and not oblique, it would not be able to cause an automatic rotation.

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THE DESIGN OF A TEMPLATE TO MEASURE SAGGITAL DISPLACEMENT ON LATERAL VIEW STRESS X-RAYS OF THE KNEE JOINT

By Angus Strover. FRCS

Presented by Glen Vardi FCSSA

OBJECTIVE

The new design of template aims to choose reference lines for the tibia and femur for measuring the relative saggittal positioning of the femoral and tibial components of the knee joint during stress Xray testing.

THE PROBLEM

The existing templates rely on tangential parallel lines drawn from the radiological projections of the posterior limits of the medial and lateral tibial and femoral condyles These condyles are relatively far apart in relation to the central saggittal plane of the knee and their Xray projections may create several difficulties in this respect, eg

I.          the difficulty in simultaneously superimposing all four projections of the tibial and femoral projections in an accurate lateral view.

2.         this difficulty may create observer error in calculating accurately the relative saggital displacement of the tibia and femur during saggittal stress radiography.

3.         these errors, due to parallax inaccuracies may be accentuated especially where anterolateral and/or posterolateral rotatory instability is involved

PRINCIPLES OF THE PRESENT DESIGN OF TEMPLATE

This the new template relies upon the projection of radiographic projection of structures placed close to the midline of the knee which produce little or no rotational change during axial rotation of the individual bones.

1.         The TIBIAL REFERENCE LINE (0-0) is applied to the radiograph along the shadow of the endocortex of  the tibia in the proximal half of the tibia with the inverted cup-shaped curved tine, or ‘cupola” applied at the apex of the inter condylar eminence This is the main reference line for the measurement of saggittal displacement.

2.         ANTERIOR FEMORAL REFERENCE LINE (B) touches the tangent to the shadow representing the subchondral bone in the depth of the trochlea.

3.         The posterior FEMORAL reference LINE (C) ( parallel to the TIBIAL REFERENCE LINE (A)) is drawn through thc angle created by the posterior endocortex of the femur and the posterior limit of the roof of the inter-condylar notch.

4.         The distances bet when 0-0 and lines B and C can be read directly from the template and the position of the anterior and posterior femoral reference lines when the knee is in the neutral or unstressed position should be marked on the acetate or paper template.

5.         During anterior translational stress, either by the application of the 1 Lachman test in 20 of flexion, or the drawer test in 90 , the translational distances can be read and marked again. The template can be kept in the patient’s notes for future reference.

EVALUATION OF THE TEMPLATE

It is proposed to give samples of the templates to several users to evaluate and report back on their convenience, any difficulties in use and their comparison with the present method of measuring anterior and posterior tibiofemoral translation.

Click here to view the template

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PTS Brace (posterior tibial Support) - a new brace concept -

M. Strobel, K. Ruse, J. Eichhom (Straubing, Germany)

In chronic PCL lesions the tibia moves posterior, clinically seen as the spontaneous posterior drawer. Patients often described pain during sitting and lying. In former times we tried reduce the pain with stretching exercises and immobilization. To reduce posterior directed forces postoperatively after PCL reconstruction we support the tibia with a towel, which is positioned at the dorsal side of the tibia in a removable 0 splint Therefore a special brace with a posterior tibial support was developed. This device we called PTS brace.

The first indication of the PTS brace was Immobilization after PCL reconstruction The patients describes a pain reduce in this brace. Therefore we used this brace to imitate the PCL function in chronic PCL insufficiencies when patients complain of pain and patellofemoral crepitus The result was an significant pain reduce. Because of the stress reduce in the femoropatellar joint and the anterior translation of the tibia we tested the brace in some patients with femoropatellar pain syndrome (IPPS), jumpers knee, femoropatellar osteoarthritis with very good results (pain reduce).

Because of this excellent first results we started to use the PTS brace since 1996 in

different indications

1.         Fresh PCL lesion (<l4d and PTD <lOmm)

2.         PCL lesion (partial rupture)

3.         PCL reconstruction     (postoperative immob. for 6 weeks)

4.         femoropatellar pain syndrome (after failing conservative conservative treatment

5.         extension deficit (after ACL reconstruction and resection anterior scars e g cyclops,

            IPCS)

6.         fixed posterior drawer

7.         Brace test in chronic PCL insuff. with FPPS)

 From 1.1.1996 -30.8.1997 we used the PTS brace for 2l2 indications in 172 patients. The indications are fresh PCL (n~18), PCL lesion (partial rupture) (n-22). PCL reconstruction (postoperative) (u=74), FPPS (n=26), Extension deficit (n~=29), fixed posterior drawer (n=47), brace test (n’26).

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THE Y LIGAMENT IN COMBINED POSTERIOR CRUCIATE AND POSTER-LATERAL COMPLEX INJURIES

BIOMECHANICS AND CLINICAL APPLICATION

Beacon. JP Laboureau. 1.-P., Ravi Kumar, R.

West Herts Knee Unit UK and Sports institute, Dijon, France

INTRODUCTION

The LARS Y ligament was developed in our Unit in 1993 from the anatomical placement system Two ­Bundle Synthetic ligament after a combined clinical programme in our Unit in Dijon.

The results from our early studies up to 1993 when analyzed and detailed found a progressive instability due to damage to the postero-lateral complex when it was not corrected.. Since 1993 we now routinely reconstruct the combined p.c.l. postero-lateral complex with the LARS  Y ligament. We have now used the Y ligament in 126 patients and our preliminary studies show that the external rotation had markedly reduced and good stability was restored following this reconstruction. The bio­mechanics and the rationale behind the design will be presented in detail.

The posterior cruciate ligament has been increasingly found to be associated with postero-lateral complex injuries and this needs to be recognized and treated at the same time as failure to do so will lead to progressive instability and a poor result as seen in our early series.

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