The Meniscus by wuxiangyu

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									   The Meniscus
        &
  Meniscal Repair
      Mr. T.D. Tennent
MBBS, BSc(Hons), FRCS(Orth)
Structure
Function
Historical Management
Current Management Options
Repair Options
Augmentation
              Structure
Bullough 1970
Fibrocartilage structure
Circumferential collagen (90% type I)
Radial Fibres
Meniscal fibrochondrocytes
Water 78%
Collagen 75% dry wt
            Structure
Articulating surface 200um thick
  isotropically oriented mesh
Inner layer anisotropically arranged
  circumferential collagen fibres and
  radial fibres
Inc proteoglycan content at horns and
  inner rim
            Structure
O’Conner 1978
Anterior and posterior horns
 innervated
              Function
Cox 1975
 Degree of degenerative change
 proportional to amt of meniscus removed

Kurosawa 1979
  Meniscectomy & 1000N load:
  30-50% increase in tibiofemoral contact
   area
  2-3x subchondral stresses
            Function
Seedhom 1979
 Removal 16-34% meniscus – 350% inc
 in contact forces

Fukubayashi 1980
 Load Transmission
 50% extension, 85% flexion
              Function
Levy 1982
  If ACL intact, no inc AP instability
  If ACL deficient, 58% inc at 900
              Function
Radin 1984
  Confirmed Kurosawa findings
  If intact peripheral rim: stresses
   well distributed
                History
Sutton 1897
  “functionless remnants of intra-articular
    muscles”


Closed reduction standard
Open excision for re-tears
               History
King 1936
  Non-uniform fibrous regeneration
  Peripheral tears – healing


Smillie 1944
  600 cases - regeneration
                History
Fairbank 1948
  Pre & postop XR up to 14 yr
  Flattening, joint space loss, osteophytes
  “possible predisposition to early
    degenerative changes”

Jackson 1968
  Clinical confirmation
             Summary
No randomised trials or comparative
 studies

Good evidence for degenerative
 changes

Good arguments for meniscal
 preservation
     Management Options
Open total meniscectomy
Arthroscopic total meniscectomy
Arthroscopic partial meniscectomy

Open meniscal repair
Arthroscopic meniscal repair
           Management
Northmore-Ball & Dandy 1983
 Open total v Open partial v Arthroscopic
 partial meniscectomy
  knee scores
  pt satisfaction
  Fairbank changes
            Management
Allen 1984
Late degenerative changes after
  meniscectomy
  210 pts:10-22 years post meniscectomy
  Radiological degeneration was seen in 18%
  increased changes in older patients,
  abnormal leg alignment,
  lateral meniscectomy
           Management
Cochrane 2000
3 trials, 260 pts
Partial / total / surgical access
Long term adv partial not established
  @6yr

No conclusions can be drawn
Meniscal Repair
        Meniscal Repair
750,000 meniscal procedures/year



1996: 136,00 repairs
2000: 200,000 repairs
          Vascularity
Arnoczky & Warren 1982
          Basic Science
Red-Red: 0-3mm
Red-White: 3-5mm
White-White: >5mm

Limits healing potential
Limits repairable menisci
      Repair Techniques
Arthroscopic
 Inside-Outside
 Outside-Inside
 Inside-Inside
    No evidence to compare

Implants
      Repair Techniques
Inside-Outside
      Repair Techniques
Outside-Inside
      Repair Techniques
Inside-Inside
       Suture v Implant
Barber 2000
  Vertical 2-0 Mersilene
  Horizontal 2-0 Mersilene
  2 Vertical 2-0 Mersilene
  Bionx Meniscus arrow (hand)
  Biostinger
  Innovasive Clearfix Screw
     Suture v Implant
Sdsorb meniscal staple
Horzontal T-fix suture
Mitex meniscal repair system (gun)
Bionx Meniscus arrow (gun)
Biomet meniscal staple (gun)
         Suture v Implant




Fig. 1. The tested implants magnified 200%: (A) Fastener, (B) Meniscal Screw,
(C) Dart, (D) Meniscus Arrow, (E) Stinger, (F) T-Fix, and (G) Ethibond 2/0 suture.
           Suture v Implant




Fig. 3. Meniscal repair devices that, in addition to the Bionx Meniscus Arrow (not shown
here), are inserted by a “gun” include, from left to right, the Surgical Dynamics SDsorb
meniscal staple, the Mitek meniscal repair system, and the Biomet staple.
Suture v Implant
       Suture v Implant
? How much strength is needed
? How much compression is produced
? How much compression is needed
? Complications
           Indications
>10mm unstable tears
Vertical-longitudinal, peripheral or
  nearly peripheral tears
Minimal degeneration of meniscus body
Traumatic mechanism of injury
>50% thickness
       Contraindications
<10mm stable longitudinal vertical tears
Radial tears <3mm, complete radial
  tears
Degenerated meniscus body
Horizontal cleavage pattern
<50% thickness
          ? Leave alone
Partial thickness
Central portion displacement <3mm
? Stable lateral tears at ACL recon
          Augmentation
Debridement
Vascular access techniques
Trephination
Synovial pedicles
Synovial abrasion
Fibrin clot
Fibrin glue
Laser welding
           Augmentation
Vascular access techniques (VAC)
 full thickness channels
 may disrupt collagen architecture
           Augmentation
Trephination
 18g needle, horizontal punctures in vascular
 zone
 90% success rate
          Augmentation
Synovial abrasion
 Synovium adjacent to repair abraided
 Augments normal response
 ? W-W efficacy
          Augmentation
Synovial pedicles
 raise flap based near meniscus
 rotate and suture to avascular area

Fibrin clot
 Provides factors required for repair
 Defect heals with normal repair tissue
 Induce and support healing in W-W
          Augmentation
Fibrin glue
 Adhesive better than natural clot
 Lacks biological factors
 ? alternative to suture of stable
 longitudinal posterior horn tears
           Augmentation
Laser
  Tissue adhesion by coagulation
  ? Stimulatory effects

O’Meara 1993
  No welding and no healing response
         Rehabilitation
                  ?
Movement and non-weight bearing
No movement and weight bearing
Limited movement and partial weight
  bearing
                  ?
           Complications
Small 1986 - 2.4%
Small 1988 – 1.5% (arthroscopy 1.7%)
Austin & Sherman 1993 – 18%

Arthrofibrosis,      Chondral damage
Neurological damage, Soft tissue reaction
Infection
DVT
       New Developments
Noyes 2000
Repair extending into avascular zone in
 pts>40 yr
93% asymptomatic
2 silent failures
6 wks protected wt bearing
4 mths protected deep flexion
6 mths running
      New Developments
Peretti 2001
Meniscal repair using engineered tissue
Devitalised meniscal tissue, pre-seeded
4x2x1.5mm chips
Nude mice 14 wks
Obliteration of interface between
  incision and scaffold
       New Developments
Venkatachalam 2001
62 repairs @ 5yrs
< 3/12: 91%
Suture alone: 78%
arrows or T-fix: 56%
Traumatic: 73%
Atraumatic: 42%
Isolated atraumatic medial: 33%
      New Developments
Jones 2002
39 repairs (Bionx arrow) @ 2yr
21 with ACL: 100%
18 stable: 2 reoperations
31.6% soft tissue problems
2 arrow migrations through skin
             Conclusions
Meniscus
Complex structure
Multiple functions
Limited repair facility
  Meniscectomy bad (?)
  Possibly leave some alone
  Meniscal repair alternative
             Conclusions
Meniscal repair
Indications expanding
Alternative techniques
Sutures stronger than implants
Sutured Acute traumatic best
ACL reconstruction beneficial
Augmentation helps (rasp, clot)
Thank You

								
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