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Operating Technique: Anatomic Reconstruction of the Medial Patellofemoral Ligament with a Free Gracilis Tendon Graft

Arno SCHMELING, M.D.Andreas WEILER, M.D., Ph.D.

Sporthopaedicum Berlin, Germany

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Operating Technique: Anatomic Reconstruction of the Medial Patellofemoral Ligament with a Free Gracilis Tendon GraftArno SCHMELING, M.D. Andreas WEILER, M.D., Ph.D. Sporthopaedicum Berlin, Germany Address for correspondence: Dr. med. Arno Schmeling Sporthopaedicum Berlin Oranienburger Strasse 70 D-13437 Berlin, Germany Telephone: +49 (0) 18 05 - 888 9 119 Fax: +49 (0) 18 05 - 888 9 113 E-mail: [email protected] Web: www.sporthopaedicum.de

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KS721: Schmeling A, Weiler A. Anatomic Reconstruction of the Medial Patellofemoral Ligament (MPFL) with a Free Gracilis Tendon Graft

KARL STORZ MediaService Tuttlingen, Germany Telephone: +49 (0) 74 61/708-0 Fax: +49 (0) 74 61/708-547 E-mail: [email protected] Internet: www.karlstorz.com

Operating Technique: Anatomic Reconstruction of the Medial Patellofemoral Ligament with a Free Gracilis Tendon Graft4

Table of Contents1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.1 Patellofemoral Instability – The Risk Factors . . . . . . . . . . . . . . . . . . . . . . 6

2. Operating Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.1 Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.2 Positioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.3 Arthroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.4 Harvesting the Graft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.5 Graft Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.6 Patellar Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.7 Femoral Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.8 Graft Passage and Fixation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.9 Postoperative Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3. Variants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.1 Open Epiphyseal Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.2 Mixed Pathologies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.3 Revisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5Operating Technique: Anatomic Reconstruction of the Medial Patellofemoral Ligament with a Free Gracilis Tendon Graft

1. Introduction

1.1 Patellofemoral Instability – The Risk FactorsIn recent years there has been an extremely rapid growth of knowledge, as well as a paradigm shift, with regard to the patellofemoral joint37.

Patellofemoral instability is the result of multiple competing factors, or risk factors, which never occur in isolation but are always present in varying degrees and are interrelated with one another.

Three main factors determine the function and stability of the femoropatellar joint:

Active stabilizers (muscles) Passive stabilizers (capsule and ligaments) Static factors (bony geometry of the femoropatellar joint).

Table 1: Overview of risk factors for patellofemoral instability

Passive stabilizers Lateral retinaculum Medial retinaculum: MPFL (medial patellofemoral ligament)

Static stabilizers Trochlear geometry: trochlear dysplasia Patellar dysplasia: no proven effect Patella alta

Alignment of extensor apparatus Tibial tuberosity-trochlear groove (TTTG) distance or Q angle

Valgus deformity Femoral anteversion, external rotation of the tibia

Other risk factors Contralateral patellar dislocation Familial occurrence

At the start of knee flexion (approximately 0–20°), mediolateral translation of the patella is limited chiefly by the medial patello-femoral complex. But as flexion increases and the patella glides into the trochlear groove (approximately 20–100°), the bony geometry of the trochlea becomes an increasingly important and dominant factor.1–3 The role of the active stabilizers past 60° of knee flexion is controversial4–5.

Based on the above combination of factors that affect patellar stability, it is clear that patellofemoral instability has a multifactorial cause. The ability to make an individual analysis and treatment decision in everyday practice depends critically on our ability to analyze the individual risk factors and their contributions on a case-by-case basis.

The great majority of patellar dislocations occur at small degrees of knee flexion.

When the knee is near extension, the medial patellofemoral ligament (MPFL) functions as the primary restraint to lateral patellar translation1, 6–8. Up to 95% of MPFL tears occur in the setting of a dislocation event9–11. It has been postulated, therefore, that reconstruction of the MPFL can restore ligamentous stability in the patellofemoral joint12–15.

2. Operating Technique

2.1 IndicationsReconstruction of the MPFL is indicated in patients with chronic recurrent dislocations of the patella. MPFL reconstruction can also be used in cases where multiple prior dislocations have already caused cartilage damage that in itself would contraindicate other procedures such as trochleoplasty or medialization of the tibial tuberosity, or in patients with concomitant rotational deformities that would require significant additional surgery16–18.

We believe that open epiphyseal plates, high-grade trochlear dysplasia, or a TTTG distance greater than 20 mm are limited indications for performing an MPFL reconstruction alone. It may be appropriate in these cases to select a different treatment or combine the MPFL reconstruction with another procedure.

Based on our experience, however, the majority of recurrent patellar dislocations can be successfully managed with an MPFL reconstruction, since most patients have moderate trochlear dysplasia with a normal TTTG distance and their dislocations occur predominantly near extension.

Various techniques for MPFL reconstruction have been described in recent years and have yielded good results17, 19–29. As the primary passive stabilizer, the MPFL is the only structure that medializes the patella at small flexion angles and also helps to stabilize the patella at higher degrees of flexion (20–45°).

1 Anatomy of the MPFL.

Adductor tubercle

Med. epicondyle

MCL

MPFL

Table 2: Indications for the MPFL reconstruction

We believe that an MPFL reconstruction is indicated for:

chronic recurrent dislocation with moderate trochlear dysplasia a torn or deficient MPFL salvage procedures in patients with cartilage damage or after failedprevious operations

adjunct for correction of other risk factors (e.g., may be combined with trochleoplasty)


Thus, if trochlear dysplasia is present, the MPFL functions as a key stabilizer even at higher angles of knee flexion. Because the MPFL does not have isometric attachment sites on the pa-tella or femur, reconstruction of the ligament should be conform to the anatomy of those attachments1, 30.

The nonisometric ligament inserts anteriorly on the upper third of the medial patellar border and posteriorly on an area between the medial epicondyle and adductor tubercle of the femur (Fig. 1).

A nonanatomic reconstruction gives rise to unphysiologic loads in the patellofemoral joint, while reconstructing only one bundle on the patella may lead to increased patellar tilt and increased rotation7, 29, 31.

Many of the techniques previously described do not take into account the actual anatomy of the MPFL. If a tendon is transferred or transposed on a pedicle, then one of the attachments – patellar or femoral – will be nonanatomic, and it will be possible to reconstruct only one of the two ligament bundles1, 32. But almost all methods with free tendon grafts employ a “single-strand” technique in which the graft is attached at one point24, 25. Besides an anatomic reconstruction, stable fixation of the tendon graft is necessary to allow for early functional rehabilitation.

The operating technique presented here for anatomic reconstruction of the MPFL (Fig. 2) uses a gracilis tendon as the free tendon graft because the mean tensile strength of the MPFL is approximately 208 N, and the tensile strength of the gracilis tendon exceeds that value1, 18. The femoral end of the graft is anchored with a biodegradable interference screw (Mega Fix®, KARL STORZ Tuttlingen). On the patellar side, two biodegradable suture anchors (4.2-mm BioPlug, KARL STORZ Tuttlingen) provide for adequate stability.

2 Principle of the anatomic MPFL reconstruction.

3 The patient is positioned supine with the leg slightly flexed and external rotated.

2.2 PositioningWe prefer a simple supine position for the MPFL reconstruction, with a side support to aid arthroscopic examination. Before the leg is exsanguinated it is wrapped with an Esmarch bandage. The leg can then be positioned comfortably on the operating table in a position of slight flexion and external rotation (Fig. 3). The slightly flexed position is advantageous as it provides some stabilization of the patella by the trochlear groove.


4 Key landmarks are drawn on the skin (a). Arthroscopy of the patellofemoral compartment in trochlear dysplasia (b–e).

b

a

d e

c

2.3 ArthroscopyFirst, the key anatomic landmarks are palpated and marked on the skin (Fig. 4a). They include the patella, medial femoral epicondyle, and adductor tubercle. It is important to know the locations of the tibial tuberosity and patellar tendon for harvesting the graft and performing arthroscopy.

An anterolateral camera portal is created, and an arthroscope is introduced to check for cartilage damage and evaluate the morphology of the trochlea.

The arthroscopic survey begins in the lateral recess (Fig. 4b). It is common to find sheared-off cartilage fragments at that location. Attention is then turned to the lateral femoral condyle (Fig. 4c), where it is common to find a small contused area. The Gilquist position, in which the light cord points downward, is a good position for evaluating the lateral overhang of the patella relative to the margin of the lateral femoral condyle (Fig. 4d). The camera is then swung into the patellofemoral compartment to check for trochlear dysplasia and evaluate the width and pathology of the medial retinacular complex (Fig. 4e).

Next the rest of the knee joint is routinely evaluated to exclude any associated pathology. Particular attention is given to the anterior cruciate ligament (ACL), whose femoral attachment can be clearly inspected in the figure-four position. A small mirror can be used to assess the condition of the cartilage on the medial patellar facet. A switching stick is inserted, and the arthroscope sheath and scope are reintroduced from the medial side to evaluate local pathology.

5 The gracilis tendon is elevated from its bed with a tendon hook.

2.4 Harvesting the GraftWhen the diagnosis has been confirmed, the gracilis tendon is harvested from the ipsilateral side. The gracilis tendon makes a good graft for anatomic reconstruction of the MPFL because its tensile strength is somewhat higher than that of the native ligament. For harvesting the gracilis tendon, an anteromedial incision approximately 1.5–2 cm long is made parallel to the tibial margin approximately 5–10 mm distal to the tibial tuberosity.

A Langenbeck retractor is placed on the medial side of the incision and a small sharp hook on the lateral side in preparation for dissection of the sartorius fascia (Fig. 5). The prominent gracilis tendon is easily palpated with a curved forceps. The sartorius aponeurosis is incised with a small scalpel just below the prominent gracilis tendon, and the tendon is exposed. At this point the gracilis tendon can easily be mobilized from its bed with a tendon hook.

Its attachments are sharply divided with a scissors, initially leaving the distal insertion intact. Next the gracilis tendon is detached proximally from its muscle belly with an open tendon stripper and then sharply released from the pes anserinus. The sartorius fascia should be closed with 3 or 4 absorbable interrupted sutures to keep the donor defect as small as possible.


2.5 Graft PreparationThe graft should have a usable length of at least 18–20 cm, depending on patient size. The gracilis tendon is placed on a tendon board and freed of muscular tissue with a sharp periosteal elevator. After the tendon has been mounted on the board and clamped at each end, all residual adherent tissues are sharply removed. The distal end of the graft is whipstitched with a No. 2 polyester suture over a length of approximately 2 cm (Fig. 6). The proximal end is initially left unsutured. Finally the tendon is wrapped in a wrung-out, slightly moist compress until reimplantation.

6 Preparation of the gracilis tendon on a tendon board: suturing the distal end of the graft.

7 Small incisions are made for the MPFL reconstruction, with landmarks drawn on the skin.

8 A bony groove approximately 1.5 cm long is cut in the superomedial patellar border with a fine rongeur (a, b).

a b

2.6 Patellar Attachment Physiologic attachment of the graft to the patella begins by making an approximately 2-cm-long incision from the supero-medial aspect of the patella to the center of the medial patellar border. The femoral incision can also be preplaced at this time by palpating the medial femoral epicondyle. The medial patellar border and the anterior and posterior patellar boundaries can be identified by palpation (Fig. 7).

The area where the patellofemoral ligament inserts on the patella is sharply exposed with a scalpel, and a bony groove approximately 1.5–2 cm long is made along the medial aspect of the patella with a fine rongeur (Figs. 8a, b). The groove must be deep enough that the gracilis tendon can be completely embedded within it.


The next step is to separate the second and third anatomic layers of the MPFL33 and dissect back to the medial epicondyle and adductor tubercle with a scissors (Fig. 9). Care is taken not to perforate the joint capsule so that intra-articular proprioception remains intact. When the graft bed has been developed, a small curved clamp is used to place a shuttle suture for passing the graft through the plane between the dissected layers.

Two absorbable suture anchors (4.2-mm BioPlug anchors) are used to attach the gracilis tendon to the patella. First, two holes are drilled at the proximal and distal ends of the notch previously cut in the patella. The laser marking on the drill bit should be watched closely to ensure that the anchors are not placed too deeply (Fig. 10a). Also, the holes should be drilled tangential to the patella so that the anchor tips will not pierce the anterior or posterior patellar surface. Next the two BioPlug suture anchors, each threaded with a No. 2 nonabsorbable braided polyester suture, are driven into the proximal and distal drill holes in the bony notch, making certain that the anchor eyelets are at a 45° angle to the bony groove (Figs. 10b, c). The anchors are driven into place with gentle hammer taps. It is essential that the holes and anchors be placed at the correct angle to ensure that the implants will have maximum pull-out strength. When the suture anchors have been inserted, they are manually tested for stability. The polyester sutures should glide freely through the eyelets.

9 The second and third medial patellofemoral layers of the MPFL are dissected to form a graft bed.

b

10 Patellar attachment: Two holes are drilled (a), and a 4.2-mm BioPlug anchor is inserted at the proximal and distal ends of the bony groove in the patella (b). KARL STORZ BioPlug anchor, 4.2 mm (c).

a c


11 Patellar attachment: Graft length is assessed, and the gracilis tendon graft is tied into place.

After graft length is assessed, the gracilis tendon is seated into the bony groove, held under tension, and tied into place (Fig. 11). An anatomical forceps may be helpful in positioning the graft. Care is taken that the tendon is completely embedded in the bony groove. The fixation is checked for stability, and the suture ends are trimmed.

2.7 Femoral Attachment The graft is pulled through the dissected tunnel with the preplaced shuttle suture (Fig. 12a), making sure that the limbs of the graft do not twist around each other. The distal limb is stretched to its full length with a small clamp, shortened as needed, and whipstitched with nonabsorbable polyester suture material (Fig. 12b). The two ends of the graft are tied together to form equal-length limbs, creating a triangular construct with a proximal and distal bundle.

To create an anatomic attachment for the graft, the medial epicondyle and adductor tubercle are palpated and dissected. Then a guidewire with eyelet is drilled in posteriorly between those two points. The wire should be drilled upward and forward so that it does not inadvertently perforate the notch. A small clamp is then placed to mark the insertion point of the guidewire (Fig. 13).

13 The femoral attachment site is marked with a guidewire and small clamp under fluoroscopic control.

12 The graft is passed through the dissected plane (a). Its distal limb is shortened and whipstitched (b).

a b

A precise anatomic insertion of the MPFL is essential for a good outcome. Incorrect placement can significantly increase the pressure on the medial patellar facet leading to a medial pain syndrome or painful flexion deficit31.

For this reason, we strongly recommend that the placement and drilling direction of the wire be checked intraoperatively, and corrected as needed, by fluoroscopic imaging in a true lateral projection of the distal femur (Fig. 13).


We know from a previous cadaver study that the radiographic femoral insertion point, when viewed in a true lateral projection (with both posterior condyles precisely superimposed), is located anterior to an imaginary line in continuity with the posterior cortex, between the proximal origin of the medial epicondyle and the most posterior point of Blumensaat’s line (Figs. 14a–d) 34–35.

2.8 Graft Passage and FixationThe correctly placed eyelet wire is brought out the lateral side of the femur. At this time the graft length is checked again so that the correct screw length can be determined. The screw should not be longer than the graft length within the bone tunnel. The tunnel is made by overdrilling the wire to the opposite cortex with a cannulated reamer. The tunnel diameter should be approximately 1 mm larger than the graft diameter. The tunnel is debrided of surrounding tissue to ensure problem-free passage of the graft. Finally the lead sutures from the graft are threaded through the tunnel with the eyelet wire and brought out the lateral side, and the graft is pulled into the femoral tunnel. Care should be taken that the proximal and distal leads do not twist around each other. To avoid irritation, the graft should be flush with the bone on the medial side.

The knee is now flexed to approximately 20–30°. This is the flexion angle at which the MPFL is under greatest tension1. The graft is pulled from the lateral side until the lateral border of the patella is even with the margin of the lateral femoral condyle (Fig. 15a).

The graft is now fixed in that position with a bioabsorbable Mega Fix® interference screw. This is done by first rechecking the tunnel position with the screwdriver to make sure that the screw is introduced in the same direction. Graft tension is checked by palpating the lateral edge of the patella with the finger (Fig. 15b).

15 The graft is pulled into position (a) and its tension checked with the knee in slight flexion (20–30°) while the patellar border is palpated (b).

a b

a b

14 Correct position of the femoral attachment on a lateral radiograph (a, b). The fluoroscopic view should be a true lateral projection of

the knee (c). Ap-view in same case (d).

c d


When driving the screw into place, make sure that the graft does not twist around the screw shank. Also, the screw should be inserted beneath bone level to prevent local irritation, especially in thin patients. This requires adequate exposure of the femoral insertion site (Fig. 16).

Before the screwdriver is removed, the knee should be taken through a full range of motion to assess patellar tracking. If necessary, graft tension can still be adjusted at this stage. If the graft is correctly positioned, the patella should track along the center of the trochlea and should still be mobile in full extension. Any lateral overhang should be corrected.

Now the tissue layers about the patella are reapproximated (Fig. 17). This is particularly important in thin patients to prevent impingement of the tendon or polyester knots on the medial patellar border. If necessary, the fixation can be reinforced by placing proximal and distal all-layer sutures through the gracilis tendon.

2.9 Postoperative CareThe knee is immobilized in a 0° splint for the first week after surgery. The splint is then replaced by a functional brace with a lateral patellar pad. The brace is set to a 60° flexion limit for 2 weeks and a 90° limit for an additional 3 weeks. Partial weight-bearing at 15–30 kg on forearm crutches is maintained for the first 3 postoperative weeks.

Quadriceps tensioning exercises should be started in the immediate postoperative period. The range of flexion is increased as the brace allows. Normal activity is permitted at 3 months, provided there is no longer a quadriceps deficit and full range of motion has been achieved. Contact sports should be avoided for at least 6 months. Generally, all patients regain a full range of motion by 4–6 weeks (Fig. 18). We have not observed a significant proprioceptive deficit in our patients compared with traditional operative techniques. This results in less thigh muscle atrophy than in other reconstructive procedures (e.g., ACL reconstruction) and provides an early capacity for quadriceps recruitment, often in the immediate postoperative period or during the first few days. This may be because the procedure is minimally invasive and extra-articular, the intraarticular situation remaines without irritation.

16 The femoral interference screw (Mega Fix®, KARL STORZ, Tuttlingen) is driven into place.

17 The medial tissue layers are reapproximated to prevent graft impingement (a). Postoperative appearance (b).

ba

18 Illustrative case at 1 week postoperatively. Full range of motion can usually be achieved within a short time.


3. Variants

3.1 Open Epiphyseal PlatesPatellofemoral instability in children with open growth plates implicates a special situation that may contraindicate bone-altering surgery. In children who have had an initial dislo-cation, primary repair of the medial retinaculum/MPFL may be appropriate in the acute stage, depending on associated pathology (intra-articular loose bodies), existing risk factors, and the precise rupture site, as this option will not alter the epiphyseal plates. As long as the repair addresses the exact rupture site, low redislocation rates can be achieved in patients with minimal trochlear dysplasia. But if a higher grade of troch-lear dysplasia is present, the redislocation rate rises significantly and there is only a relative indication for performing a repair36.

In the MPFL reconstruction, the femoral insertion is located precisely in the epiphyseal plate area of the distal femur. Consequently, a tradeoff must be made between stabilizing the patella and sparing the growth plates. Patellar graft fixation is also a frequent problem in children, since the patella is often quite small and cartilaginous and cannot withstand drilling.

19 Radiograph illustrating faulty graft placement (red). Green: correct placement.

Other causes are anchor penetration into the joint (Fig. 20), MPFL reconstruction in patients with markedly present patello-femoral osteoarthritis, and high-grade underlying trochlear dysplasia.

These errors can be avoided by the conscientious use of inra-operative fluoroscopy and by careful patient selection.

20 Illustrative case: intra-articular perforation of an anchor (retropatellar view) and its removal.

3.3 RevisionsAs growing numbers of MPFL reconstructions have been performed in recent years owing to the highly promising results, the number of revisions has also been increasing. Revisions are often performed to relieve medial pain syndrome due to faulty placement of the femoral graft attachment (Fig. 19).

If an MPFL reconstruction is still elected, the tendon graft can be fixed to the periosteum by suture in many cases. Depending on local anatomy, it may even be possible to insert two small suture anchors right next to the growth plate (under fluoro-scopic control!). The indications for an MPFL reconstruction should be carefully considered in this age group, however.

3.2 Mixed PathologiesAn MPFL reconstruction alone is often inadequate in patients with high-grade trochlear dysplasia, rotational deformities, massive patella alta, a lateral contracture, or an abnormally large TTTG distance (> 20 mm). The dominant pathology in these cases should be addressed (trochleoplasty, osteotomy of the tibial tuberosity, etc.) following a detailed analysis of risk factors.

Nevertheless, it may still be necessary to reconstruct the MPFL as an adjunct to trochleoplasty, for example, since the MPFL is often deficient in the presence of trochlear dysplasia.

Note: An analysis of individual risk factors and a thorough clinical examination are an essential prelude to patient selection!


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Tendon Harvesting and Preparation

28729AC Open Tendon Stripper, graduated, diameter 7.5 mm, length 30 cm

28729SH Tendon Hook

28729AC

28729SB Tendon Board, including FLIPPTACK® Retainer 28729SC

28729SB

213008 PLESTER Elevator, width 8 mm, length 18 cm

213008

It is recommended to check the suitability of the product for the intended procedure prior to use.


28729SD

28729SD Tendon Thickness Tester, for determination of tendon thickness size 4–7 mm at intervals of 0.5 mm

28729P Tissue Forceps, 1 x 2 teeth, medium, distal curved to left, length 14.5 cm

28729P

Tendon Harvesting and Preparation


Suture Anchoring System BioPlug

2870411BP BioPlug, bioresorbable suture anchor, diameter 4.2 mm, length 11 mm, sterile, for single use, for use with Inserter 28179TI or 28179KI

28179KB

28179KB Drill, for preparation of the tunnel for BioPlug 2870411BP, with lasermarking for the depth of the drill hole, diameter 3.7 mm, length 15 cm

28179KI Inserter, with lateral thread guide and thread clip at the handle, working length 9 cm, for use with BioPlug 2870411BP

28179KI


Bone Drill

28729BA–BH

28729BA Bone Drill, cannulated, diameter 4.5 mm, for use with Drilling Wire 28729D and Larding Wire 28729E

28729BB Same, diameter 5 mm28729BI Same, diameter 5.5 mm28729BC Same, diameter 6 mm28729BK Same, diameter 6.5 mm28729BD Same, diameter 7 mm28729BL Same, diameter 7.5 mm28729BE Same, diameter 8 mm28729BM Same, diameter 8.5 mm28729BF Same, diameter 9 mm28729BN Same, diameter 9.5 mm28729BG Same, diameter 10 mm28729BO Same, diameter 10.5 mm28729BH Same, diameter 11 mm


Mega Fix® B

Mega Fix® P

2870619B Mega Fix® B, bioresorbable interference screw, diameter 6 mm, length 19 mm, sterile

2870623B Same, length 23 mm




2870928B Same, length 28 mm

2870723B Same, length 23 mm2870728B Same, length 28 mm

2870823B Same, length 23 mm2870828B Same, length 28 mm

2870823P Mega Fix® P, bioresorbable interference screw, perforated, diameter 8 mm, length 23 mm, sterile

2870828P Same, length 28 mm


2870928P Same, length 28 mm2870935P Same, length 35 mm


2871035P Same, length 35 mm



Mega Fix® C

Mega Fix® CP

2870823CP Mega Fix® CP, bioresorbable composite interference screw, perforated, diameter 8 mm, length 23 mm, sterile

2870828CP Same, length 28 mm

2870928CP Same, length 28 mm2870935CP Same, length 35 mm

2871035CP Same, length 35 mm




2870728C Same, length 28 mm

2870819C Mega Fix® C, bioresorbable composite interference screw, diameter 8 mm, length 19 mm, sterile










Screwdriver

28789SK CrossDrive® Screwdriver, cannulated, size 8 – 11, for use with bioresorbable Mega Fix® screws diameter 8 – 11 mm and Nitinol Guide Wires 28789GW/KW

28770SK CrossDrive® Screwdriver, cannulated, size 7, for use with bioresorbable Mega Fix® screws diameter 7 mm and Nitinol Guide Wires 28789GW/KW

28760SK CrossDrive® Screwdriver, cannulated, size 6, for use with bioresorbable Mega Fix® screws diameter 6 mm and Nitinol Guide Wires 28789GW/KW

28789SK


Notes:


Notes:


Notes:


WITH COMPLIMENTS OF

KARL STORZ –– ENDOSKOPE

Documents

Operating Technique - Karl Storz SE · 2020-06-15 · Operating Technique: Anatomic Reconstruction of the Medial ... As new research and clinical experience broaden our knowledge,