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Arthrosc Tech
Arthrosc Tech
Arthroscopy Techniques
2212-6287
Elsevier

S2212-6287(24)00153-1
10.1016/j.eats.2024.103044
103044
Technical Note
Knee
Repair of the Anterior Horn of the Lateral and Medial Meniscus With Knotless Suture Anchor
Pimprikar Milind V. M.S.D. Ortho., P.G. Dip. Sports and Exercise Medicine milindpimprikar95@gmail.com
∗
Patil Hitendra G. M.B.B.S., D.N.B.
Dr. Pimprikar’s ADTOOS Clinics, Nashik, Maharashtra, India
∗ Address correspondence to Dr. Milind V. Pimprikar, M.S.D., P.G.Dip., Dr. Pimprikar’s ADTOOS Clinics, Nashik, Maharashtra, India. milindpimprikar95@gmail.com
03 8 2024
9 2024
03 8 2024
13 9 10304422 1 2024
3 4 2024
© 2024 The Authors
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
The anterior horn lateral meniscus tear often is accompanied by perimeniscal cysts, which are treated with arthroscopic cyst excision with outside-in repair of the anterior horn. After cyst excision, there is a large gap between the thin anterior capsule and the anterior horn, which sometimes does not allow a stable repair. The suture knots may be palpable below the skin postoperation and cause irritation. A recently published technique repairs the anterior horn with a suture anchor using a suture lasso technique. We suggest a modification using a knotless anchor instead of a suture anchor, which allows a predictable tension across the repair when deployed. This technique can be used for both anterior horn lateral meniscus and anterior horn medial meniscus repairs. This technique is easy to perform, less time consuming, and reproducible.

Technique Video
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pmcThe menisci in the knee are important structures that impart stability, load distribution, and lubrication to the joint. They function as secondary stabilizers, providing proprioception and cartilage nutrition.1 Anterior horn tears of the lateral meniscus (AHLM) with perimeniscal cysts are a common occurrence (Fig 1). They are treated by arthroscopic cyst excision with the repair of AHLM using an outside-in technique.2 After the cyst excision, there is a large gap left behind between the thin anterior capsule and the AHLM, thus making outside-in repair difficult. In this Technical Note, we describe a technique using a knotless anchor to repair the AHLM securely and predictably after resection of the cyst. The same technique is used for anterior horn tears of the medial meniscus (AHMM) repairs.Fig 1 (A) Left knee at 90° of flexion showing parameniscal cyst at anterolateral soft spot of the knee. (B) Left knee at 90° of flexion showing parameniscal cyst at anterolateral soft spot of the knee. (C) MRI sagittal section T2-weighted image showing parameniscal cyst and extent of the cyst. Blue stars: multiloculated parameniscal cyst. (D) MRI sagittal section T2-weighted image showing parameniscal cyst and extent of the cyst. Blue star: infrapatellar fat pad; red star: area of anchor insertion. (AHLM, anterior horn lateral meniscus; MRI, magnetic resonance imaging.)

Operative Steps (AHLM)

Patient Positioning and Portals

The patient, under spinal anesthesia with a tourniquet applied, is placed supine on the operation table. Standard arthroscopic portals are used. The anterolateral (AL) portal is made first in a higher position, avoiding the cyst on the anterolateral aspect. An anteromedial portal (AM) is made under arthroscopic visualization with a 30° arthroscope. A diagnostic round of the knee is taken to identify the exact cyst location below the intermeniscal ligament (Fig 2, Video 1).Fig 2 Left knee at 90° of flexion viewing through the anteromedial portal showing blue line: intermeniscal ligament (IML); blue star: perimeniscal cyst, probe from AL port probing the IML and lateral femoral condyle (LFC). (ACL, anterior cruciate ligament.)

Excision of the Cyst

After performing a diagnostic arthroscopy, the scope is switched to the AM portal, and a 3.5-mm. shaver (DYONICS; Smith & Nephew, Andover, MA) is introduced through the AL portal. The fat around the cyst wall is shaved, and the cyst is exposed. A punch biopsy is taken from the cyst wall and is sent for the histopathology (Fig 3). The cyst is then entered from the outside with an 18-gauge spinal needle to locate the position inside the joint. The cyst wall is completely excised with the help of a shaver and the radiofrequency ablator (Fig 4).Fig 3 Left knee at 90° of flexion viewing through the anteromedial portal showing punch biopsy from the wall with a biopsy punch (ACUFEX; Smith & Nephew) from the anterolateral portal. (ACL, anterior cruciate ligament; LFC, lateral femoral condyle.)

Fig 4 Left knee at 90° of flexion viewing from the anteromedial portal with scope directed towards the retropatellar region showing a red star: excised cyst, edge of the capsular rent; blue star: exposed tibia; blue line: lateral edge of the patellar tendon.

Passage of Sutures

A No. 2 FiberWire (Arthrex, Naples, FL) is loaded on a self-suture retrieving device FIRSTPASS MINI (Smith & Nephew), and a stitch is taken through the meniscocapsular junction of AHLM in a mattress fashion (Fig 5). Another stitch is taken similarly to cover the entire length of the tear. The knots are tied using a knot pusher with half hitches to secure the fixation (Fig 6).Fig 5 (A) Left knee at 90° of flexion viewing through the anteromedial (AM) portal showing the first completed mattress suture. Self-retrieving device inserted from the anterolateral port (FIRSTPASS MINI; Smith & Nephew) taking a bite through the meniscocapsular junction (MCJ) and lateral femoral condyle (LFC). (B) Left knee at 90° of flexion viewing through the AM portal showing blue stars: bites taken through the MCJ with a no. 2 FiberWire in mattress configuration. (AHLM, anterior horn of lateral meniscus; LFC, lateral femoral condyle.)

Fig 6 Left knee at 90° of flexion viewing through the anteromedial port showing knot pusher using a sliding knot to secure the repair from anterolateral port. Black line: edge of the capsule. (AHLM, anterior horn of lateral meniscus; LFC, lateral femoral condyle.)

Tibial Preparation and Anchor Fixation

The anterolateral aspect of the tibia is prepared, and a hole is punched with a starting awl. Taking care of the soft-tissue bridges, (Fig 7) a 4.5-mm. knotless suture anchor (Biotek, Gujarat, India) is inserted in the punched hole (Fig 8). The tension over the sutures is adjusted, and the anchor is fixed at 90° of knee flexion. The procedure is completed by cutting the suture ends (Fig 9).Fig 7 (A) Left knee at 90° of flexion viewing through the anteromedial (AM) portal showing 2 mattress sutures taken through the meniscocapsular junction (MCJ) and site of anchor fixation (blue star). (B) Left knee at 90° of flexion viewing through the AM portal showing suture retriever through the anterolateral portal retrieving all the sutures to avoid soft-tissue bridge. (C) Left knee at 90° of flexion viewing through the AM portal showing the meniscocapsular junction (MCJ), starting punch for the knotless anchor (4.5-mm PEEK [polyether ether ketone]; Biotek), and patellar tendon. (AHLM, anterior horn of lateral meniscus; LFC, lateral femoral condyle.)

Fig 8 Left knee at 90° of flexion viewing through the anteromedial portal showing a knotless anchor (4.5-mm PEEK; Biotek) from the anterolateral portal fixed in the previously punched hole. (AHLM, anterior horn of lateral meniscus.)

Fig 9 Left knee at 90° of flexion viewing through the anterolateral portal showing completed repair with knotless anchor in place. (AHLM, anterior horn of lateral meniscus; LFC, lateral femoral condyle.)

Operative Steps (AHMM)

Patient Positioning and Portals

The patient, under spinal anesthesia with a tourniquet applied, is placed supine on the operation table. Standard arthroscopic portals are used. A diagnostic round of the knee is taken to identify the exact cyst location below the intermeniscal ligament (Fig 10A, Video 1).Fig 10 (A) Left knee at 90° of flexion viewing through the anterolateral portal showing probing the perimeniscal cyst from anterior horn medial meniscus (AHMM), (B) Left knee at 90° of flexion viewing through the anteromedial (AM) portal showing a punch biopsy from the cyst wall with a biopsy punch (ACUFEX; Smith & Nephew) from the anterolateral (AL) portal, cyst fluid is seen extruding and the relation to the joint capsule. (C) Left knee at 90° of flexion viewing through AM portal showing complete cyst excision. Black outline shows cyst wall. (D) Left knee at 90° of flexion viewing through the AM portal showing antegrade suture passing device (FIRSTPASS MINI; Smith & Nephew) from the AL portal taking a stitch through the anteromedial capsule with No. 2 FiberWire. (E) Left knee at 90° of flexion viewing through the AM portal showing antegrade suture passing device (FIRSTPASS MINI) from the AL portal taking a stitch through the meniscocapsular junction of anterior horn of medial meniscus (AHMM) with No. 2 FiberWire. (F) Left knee at 90° of flexion viewing through AM portal showing an arthroscopic sliding knot tied with a knot pusher. (G) Left knee at 90° of flexion viewing through the AM portal showing deployment of a 4.5-mm knotless anchor (Arthrex) to fix the anterior horn of the medial meniscus. (H) Left knee at 90° of flexion viewing through the AM portal showing capsular closure over the AHMM repair using a transparent canula from the AL portal. (AHMM, anterior horn medial meniscus; AMC, anteromedial capsule; AMT, anteromedial tibia; MFC, medial femoral condyle.)

Excision of the Cyst

The scope is switched to AM portal and an 18-gauge spinal needle is used to puncture the cyst. A 3.5-mm shaver (DYONICS) is used to clear the cyst from the surrounding synovium. A hook probe and shaver are then used to completely dissect and excise the cyst after the punch biopsy from the cyst wall (Fig 10B). The cyst wall can now be seen (Fig 10C).

Suture Passage

With antegrade suture passing device (FIRSTPASS MINI) loaded with no. 2 FiberWire a stitch is taken through the capsule in mattress fashion and the sutures are parked in AL portal (Fig 10D). In the same manner another stitch is taken in the meniscocapsular junction of AHMM and a sliding knot is tied (Fig 10 E and F).

Tibial Preparation and Anchor Fixation

The anteromedial aspect of the tibia is prepared, and a hole is punched with a starting awl (Fig 7C). Taking care of the soft-tissue bridges, a 4.5-mm knotless suture anchor (Arthrex) is inserted in the punched hole (Fig 10G). The tension over the sutures is adjusted, and the anchor is fixed at 90° of knee flexion. The capsular stitch is now tied over the AHMM repair. The procedure is completed by cutting the suture ends (Fig 10H).

Discussion

AHLM tears usually are associated with the perimeniscal cysts.3 Achieving complete cyst excision and simultaneous repair of the AHLM is challenging. The integrity of the AHLM is important for normal knee kinematics, and the tear of AHLM increases the peak contact pressures over the lateral and medial tibiofemoral compartments.4 Among the prevailing methods of the meniscus repair (outside-in, inside-out, and all-inside), outside-in is the preferred method of repairing AHLM. This technique uses inexpensive material like spinal needles and sutures like polydioxanone for the repair.5 The thin nature of the anterolateral capsule is fraught with increased chances of a cutting through of the suture. Another recently published method uses a suture anchor for the fixation of the AHLM after taking a lasso loop around the meniscus tissue.6 A lasso loop around the AHLM may lead to strangulation of the meniscus tissue and may impede the healing.

Presently, the literature supports repairing AHLM with outside-in repair.7 Because of the thin nature of the anterolateral capsule and fewer attachments of the capsule to the lateral meniscus, imparting more mobility to the lateral meniscus, we feel the outside-in method of repair would constrain the excursion due to multiple sutures taken from the capsule and the meniscus. Knot irritation can also cause pain in the anterolateral aspect of the knee.8

To overcome these disadvantages (Table 1), we have used a horizontal configuration of the sutures taken through the periphery of the AHLM with No. 2 FiberWire and fixed to the anterolateral aspect of the tibia using a 4.5-mm knotless anchor (Biotek).Table 1 Advantages and Disadvantages

Advantages	Disadvantages	
Can be used for both AHLM and AHMM repairs.	Requires use of specific instruments (FIRSTPASS MINI).	
Does not strangle the meniscus tissue.		
No knot irritation.		
Easy to execute.		
Reproducible with lesser learning curve.		
AHLM, anterior horn lateral meniscus; AHMM, anterior horn medial meniscus.

This technique is specifically indicated in patients with anterior horn tears with perimeniscal cysts, which will accomplish a complete cyst excision and anterior horn repair. This technique is not recommended in patients with advanced degeneration, AHLM radial, or macerated tears.

In this Technical Note, we propose a technique allowing complete excision of the perimeniscal cyst and AHLM repair using a knotless anchor. The bites are taken through the meniscocapsular junction and not through the entire anterior horn of the meniscus as described by some authors,6 which prevents strangulation of the meniscal tissue, thus providing a predictable and reproducible repair.

AHMM Cysts

AHMM cysts are less frequently seen than AHLM. They are about 9 times less frequent than AHLM.9 Approximately 85% of the cysts are associated with meniscus tears.10 To prevent the recurrence after cyst decompression, these tears should be repaired. The same technique described previously for the repair of AHLM can be used for AHMM.

The attachment of AHMM is classified into 4 types, of which type 2 forms 45.7%, followed by type 1, accounting for 42.9%.11 Type 3 and type 4 each account for 5.7% each.6 There is an additional attachment to the Intermeniscal ligament and the infrapatellar synovial fold.11,12 These insertion areas are amenable to arthroscopic intervention; hence, arthroscopic cyst excision with AHMM repair remains a good option.

The technique described in this article also can be used for the anterior horn of the medial meniscus with the perimeniscal cyst. Since the AHMM has an attachment to the synovial fold an additional stitch is taken through the capsule over and above the AHMM repair. This technique is useful in both AHLM and AHMM tears with parameniscal cysts. This technique should not be used in presence of macerated tears of AHLM. The risks and limitations are listed in Table 2.Table 2 Limitations and Risks

Limitations	Risks	
• Cannot be used in macerated anterior horn tears.

• Radial tears near the anterior horn need exclusion.

	• Incomplete removal of the cyst wall.

• Improper insertion of the anchor.

• Anchor breakage or pull out.

	

Disclosures

All authors (M.V.P. and H.G.P.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Supplementary Data

Video 1

A diagnostic arthroscopy is done using standard arthroscopy portals with the patient in the supine position with knee at 90° of flexion. The tear of the anterior horn of the lateral meniscus (AHLM) is confirmed. The probe is passed from the anteromedial (AM) portal to identify the presence of cyst below the intermeniscal ligament. The scope is switched to the AM portal, and the cyst is then entered from the outside with an 18-gauge spinal needle to locate the position inside the joint. A 3.5-mm. shaver (DYONICS; Smith & Nephew) is introduced through the anterolateral (AL) portal. The fat around the cyst wall is shaved, and the cyst is exposed. A punch biopsy was taken from the cyst wall and was sent for the histopathology. The cyst fluid can be seen exuding out, confirming intracystic location of the shaver tip. The cyst wall is completely excised with the help of a shaver and the radiofrequency ablator. The hook probe is inserted to palpate the retropatellar region, the patellar tendon, area of anchor insertion, and the AHLM. A No. 2 FiberWire is loaded on a self-suture retrieving device FIRSTPASS MINI (Smith & Nephew), and a stitch was taken through the meniscocapsular junction of AHLM in a mattress fashion. Another stitch is taken similarly to cover the entire length of the tear. The knots are tied using a knot pusher with half hitches to secure the fixation. A suture retriever is passed, and both the stitches are taken into the retriever through the same port to avoid soft-tissue bridge. Then, attention is directed toward the preparation of the anterolateral aspect of tibia for anchor fixation. The anterolateral aspect of the tibia is prepared to uncover the subchondral bone, and a hole is punched with a starting awl. Taking care of the soft-tissue bridges, a 4.5-mm knotless suture anchor is inserted in the punched hole. The tension over the sutures is adjusted, and the anchor is fixed at 90° of knee flexion. The procedure is completed by cutting the suture ends and examining the final repair. The same technique is used for the anterior horn of the medial meniscus (AHMM) tears with parameniscal cysts. With standard arthroscopy portals, a probe is passed through the AM portal and the extent of the cyst is examined. The scope is shifted to the AM port and an 18-gauge spinal needle was passed from the AL portal to puncture and confirm the location of the cyst. A 3.5-mm shaver tip (DYONICS; Smith & Nephew) is passed through the AL portal to completely expose the cyst. A hook probe was passed to delineate and dissect the cyst. A punch biopsy is taken for histopathological examination. The cyst fluid is seen extruding at this point in time. Complete cyst evacuation is carried out with the help of a hook probe and cyst wall was shaved off exposing the anteromedial aspect of the tibia. The capsular rent is identified and repairability is confirmed with the help of a tissue grasper (ice tong; Smith & Nephew). A self-retrieving suture passer (FIRSTPASS MINI) is passed to take the bites through the anteromedial capsule and is parked in the AL port. Now, attention is diverted to the AHMM. A stitch is taken through the meniscocapsular junction of the AHMM in a mattress configuration with an antegrade suture passing device. The arthroscopic knot is tied with a knot pusher. Here after the preparation of the anteromedial tibial surface is done with a starting punch, which is introduced to punch a hole for a 4.5-mm knotless anchor (Arthrex). The meniscocapsular sutures are threaded through the anchor and the anchor is deployed. After cutting the sutures from the anchor, the capsular stitch is tied to reattach the capsule completing the repair. The hook probe is then passed to examine the final repair along with the intermeniscal ligament.
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References

1 Allen A.A. Caldwell Jr GL Fu F.H. Anatomy and biomechanics of the meniscus Op Tech Orthop 5 1995 2 9
2 Chen D. Li Q. Sun Y. Qin J. Yao Y. Jiang Q. Arthroscopic management for the unstable inferior leaf of the lateral meniscus anterior horn and associated cysts through a direct inframeniscal portal: A retrospective study Biomed Res Int 2017 2017 9264907
3 El-Assal M. Mostafa M. Abdel-Aal A. El-Shafee M. Arthroscopy alone or in association with open cystectomy: In treatment of lateral meniscal cysts Knee Surg Sports Traumatol Arthrosc 11 2003 30 32 12548448
4 Prince M.R. Esquivel A.O. Andre A.M. Goitz H.T. Anterior horn lateral meniscus tear, repair, and meniscectomy J Knee Surg 27 2014 229 234 24227397
5 Menge T.J. Dean C.S. Chahla J. Mitchell J.J. LaPrade R.F. Anterior horn meniscal repair using an outside-in suture technique Arthrosc Tech 5 2016 e1111 e1116 28224064
6 Fu G. Pang J. Li G. Lu J. Chen J. Arthroscopic repair for the anterior horn of the lateral meniscus with suture anchor Arthrosc Tech 12 2023 e635 e638 37323780
7 Rodeo S.A. Arthroscopic meniscal repair with use of the outside-in technique Instr Course Lect 49 2000 195 206 10829175
8 Thompson W.O. Thaete F.L. Fu F.H. Dye S.F. Tibial meniscal dynamics using three-dimensional reconstruction of magnetic resonance images Am J Sports Med 19 1991 210 215 ; discussion 215-216 1867329
9 Maffulli N. Petricciuolo F. Pintore E. Lateral meniscal cyst: Arthroscopic management Med Sci Sports Exerc 23 1991 779 782 1921669
10 Mills C.A. Henderson I.J. Cysts of the medial meniscus. Arthroscopic diagnosis and management J Bone Joint Surg Br 75 1993 293 298 8444952
11 Brown A.A. The insertion of the anterior horn of the medial meniscus: An anatomic study Muscles Ligaments Tendons J 3 2013 210 212 24367782
12 Ohkoshi Y. Takeuchi T. Inoue C. Hashimoto T. Shigenobu K. Yamane S. Arthroscopic studies of variants of the anterior horn of the medical meniscus Arthroscopy 13 1997 725 730 9442326
