Abstract
Background:
Meniscal radial tears are associated with altered contact mechanics, as they have the potential to disrupt the meniscal hoop stress mechanism. In prior studies, radial tears are associated with higher grade of cartilage damage, as well as higher rate and severity of meniscal extrusion in knees with a radial tear relative to other types of tears. Improved understanding of the meniscus biological potential together with modern developments in surgical technique has paved the way for the current emphasis on repairing even radial tears.
Indication:
Large or complete radial tears of the meniscus without prohibitive joint space narrowing or severe cartilage damage.
Technique Description:
A hybrid technique of meniscal radial repair is described, combining (1) 2 transtibial pullout cinch-loop sutures, (2) 2 inside-out vertical rip-stop sutures and 2 oblique sutures in a “cross-tag” configuration, and (3) 1 horizontal mattress all-inside suture. The repair is biologically augmented with a notch marrow-venting procedure.
Results:
Recent evidence has demonstrated significant biomechanical benefit in terms of increased load to failure and construct strength when adding transtibial tunnel augmentation to radial repairs. In addition, rip-stop sutures decrease the chance of cut-out relative to nonreinforced repairs. Those biomechanical advancements are reflected in excellent patient-reported outcomes as well as healing rates following radial repair.
Discussion/Conclusion:
We present a hybrid technique encompassing the most biomechanically effective novel radial repair techniques, backed by excellent clinical outcomes following radial repair in the current literature.
Patient Consent Disclosure Statement:
The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.
This is a visual representation of the abstract.
Video Transcript
Radial tears of the meniscus have the potential to damage the vital circumferential fibers, resulting in significant loss of hoop stress function that leads to increased contact pressure, leading to cartilage damage and meniscal extrusion.1,12
Radial tears encompass the avascular white-white zone of the meniscus and have been historically considered irreparable and therefore treated with meniscectomies. 11 While patients largely experience short-term symptomatic relief following a meniscectomy, 4 an overwhelming number of studies ultimately demonstrated the deleterious long-term effects of this approach, ultimately leading to an increased risk of knee osteoarthritis (OA).2,5,6,8,11
The biological healing potential in the more central areas of the menisci has been found to be higher than previously thought, as multipotent mesenchymal stromal progenitor cells and microvasculature were recently demonstrated in the white-white zone. 3 Improved understanding of the meniscus biological potential together with modern developments in surgical technique has paved the way for the current emphasis on repairing even radial tears.3,7,9-11
In this video, we present a case of a medial meniscus mid-body radial tear treated with a hybrid technique of meniscal repair.
Our patient was a 53-year-old man who sustained an episode of acute pain during hiking, without direct trauma, 3 months prior to the first consultation. Patient reported persistent right knee medial pain, but no clear mechanical symptoms. Physical examination revealed a slight varus alignment without dynamic lateral thrust, 1+ effusion, full range of motion, medial joint line tenderness to palpation, and a positive McMurray test.
Preoperative radiographs revealed minimal medial joint space narrowing and a 2° varus alignment on standing long-limb radiograph.
Magnetic resonance imaging (MRI) revealed a radial tear at the mid-body of the medial meniscus, demonstrated here on coronal, sagittal, and axial sequences.
Following a complete arthroscopic inventory, the radial tear is visualized at the mid-body of the medial meniscus and palpated here with a probe in order to fully assess tear configuration. The portals will then be subsequently switched, to allow for a better attack angle via anterolateral portal instrumentation. The frayed margins of the tear are debrided with the use of a shaver, and both fragments of the meniscus are mobilized to determine fragment reduction. An arthroscopic rasp is used to stimulate healing potential.
The repair is initiated with a self-retrieving all-inside all-suture device, which is used to pass one high-strength nonabsorbable suture in each meniscal fragment, using a cinch-loop configuration. With the aid of an anterior cruciate ligament (ACL) aiming device, a transtibial tunnel is created under the reduced meniscal fragment in order to promote reduction of the displaced fragment during suture tensioning. The sutures are shuttled through the tunnel with the aid of a Prolene suture or Nitinol monofilament wire, tensioned and tied over a suspensory cortical fixation device.
Next, using an inside-out technique with the aid of an accessory posteromedial incision for placement of a popliteal retractor, 2 vertical mattress “rip-stop” sutures are passed in order to enhance the biomechanical strength of the repair construct. These are followed by 2 horizontal—or in this case oblique—inside-out sutures in a “cross-tag” configuration (a recently described modification of the hash-tag technique).
The inside-out sutures are tensioned and then knot tying ensues. The repair is finished with one all-inside anchor-based suture, in a horizontal configuration, to optimize the apposition of the tear margins. A notch marrow-venting technique is finally performed with 3 to 5 small perforations on the anterior aspect of the lateral wall to promote migration of mesenchymal cells and stimulate healing.
Postoperative radiographs reveal the trajectory of the transtibial pullout tunnel and the suspensory cortical fixation device on the anteromedial tibia.
Rehabilitation is approached in a stepwise fashion, with a critically important 6-week period of nonweightbearing to avoid irreversible stretching of the repair before healing takes place. The patient will ideally have recovered full range of motion at 6 weeks, at which point weightbearing as tolerated is initiated and progressed to full weightbearing and independent gait by week 8. Strengthening progression ensues, and running progression and sports-specific gestures are initiated at 12 to 16 weeks.
Technical pearls to radial repair include always working under optimal visualization, with medial collateral ligament (MCL) pie-crusting as a procedural step whenever there is a radial tear or a tear of the posterior horn of the medial meniscus. Positioning of the tunnel is under the nondisplaced meniscal fragment to achieve optimal reduction and apposition of the margins. Biomechanically augment your radial repair with a transtibial pullout and/or vertical rip-stop sutures. And biologically augment your repair with techniques such as marrow venting, fibrin clot, and trephination.
A recent systematic review assessed the collective evidence regarding the biomechanical properties of radial repair, including novel techniques. 9 Across 20 studies, there was evidence of significant biomechanical benefit to using transtibial pullout augmentation, with improved load to failure and smaller displacement. Investigations on the effect of “rip-stop” reinforcement sutures have consistently pointed to minimized risk of suture cut-out in reinforced constructs (eg, “hash-tag,”“cross-tag,”“rebar”) relative to nonreinforced ones. The authors reported that all-inside techniques largely resulted in higher load to failure and construct stiffness relative to inside-out repair in the collated literature. 9
In terms of clinical outcomes following radial repair, a systematic review with 12 eligible studies and a pooled sample of over 200 repairs found significantly improved patient-reported outcomes at a mean 35-month follow-up, with marked improvements in Lysholm, International Knee Documentation Committee (IKDC), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Tegner scores. The authors also reported that upon second-look arthroscopy, 92% of the cases in the literature display some degree of healing, with more than 60% of cases presenting complete healing. 7
In summary, we present a hybrid technique for radial repair of the medial meniscus, employing all techniques that are found to have significant biomechanical benefit, that is backed by current biomechanical and clinical literature, reflecting the current emphasis on meniscal preservation.
Footnotes
Submitted June 11, 2023; accepted July 27, 2023.
One or more of the authors has declared the following potential conflict of interest or source of funding: C.E.F. has received educational support from Smith + Nephew. M.S.K. has received educational support from Johnson & Johnson. M.V.L. has received educational support from Johnson & Johnson and Zimmer Biomet. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
