Treatment of meniscus tears has advanced significantly over the last several years. Newer techniques and technology have improved healing, and studies have shown improved longterm outcomes with meniscus repair versus meniscectomy.

1. Meniscus – Anatomic, Biologic, and
Biomechanical Factors That Affect
Tear Prognosis
Jeremy M. Burnham, MD
UPMC Sports Medicine
July 22, 2017 – AOSSM Annual Meeting

2. What Affects Prognosis?
McDermott, Amis JBJS (Br) 2006
• 75% decrease in contact area
• 235% increase in peak pressures

3. What Affects Prognosis?
• Tear Factors
– Location
– Vascular Zone
– Tear Size
– Tear Pattern
• Injury
– Acute vs. Chronic
– Concomitant Injuries
– Alignment & Stability
• Patient
– Age, BMI, Activity
McDermott, Amis JBJS (Br) 2006

4. Meniscus Vascularity
• Entire meniscus is vascular at birth,
but inner 1/3 avascular by nine months
• In adults, outer 10-30% is vascular
• Formation of a clot is essential for
healing, and tears in the red-red zone
(outer 1/3) are most likely to heal
• Fibrin clots, abrading synovium
adjacent to repair, and “freshening up”
the tear site are ways to improve
healing

5. Meniscus Vascularity

6. Patient Age
• Older patients have less cellularity and decreased healing
response
– Retears more frequent in patients >30 (Eggli et al. AJSM 1995)
– Older patients had longer time to failure (Bach et al. J Knee Surg
2005)
• Mixed Clinical Results
– No RCTs
– Selection bias (most surgeons won’t repair degenerative tears)

7. Older Patients, Chronic Tears
• RCT, Level I Evidence
• 102 pts with knee pain and degenerative tear of the PH
of the medial meniscus
• Excluded: trauma, ligament deficiency, systemic
arthritis, osteonecrosis

8. Older Patients, Chronic Tears

9. Older Patients, Chronic Tears
• Average duration of symptoms prior to treatment ~8 mths
– Nonop: Medicine, PT 3x/wk for 3 wks, HEP for 8 wks
– Operative: Partial menisectomy
• Pain improved more quickly in operative group, but no difference
at 2 years
• No differences in satisfaction, Lysholm, or OA progression at 2
years

10. 10

11. 11
Chronic, Complex Pattern, Older Patients

12. Acute Tears, Young or Old Patients
• Cohort study
• 339 meniscus repairs (136 <40y, 45 >40y)
• 4.4 to 12% lost to follow up
• Minimum follow-up 10 years
• All inside-out repairs
• No postoperative PRO difference (Lysholm, WOMAC, SF-12)
between groups

13. Acute Tears, Young or Old Patients
• Patients <40 and >40 improved similarly after meniscus repair
• Failure rate at minimum of 10 years ~5% in both groups

14. Meniscus Tear Pattern
• Tear Pattern
– More reparable tears found in
unstable as compared to stable
knees
– Double longitudinal and complex
tears have low rate of healing
– Horizontal cleavage tears may
be asymptomatic
– Partial radial tears in avascular
region may require only
debridement
– Complete radial tears and root
tears are equivalent to total
meniscectomy
(Starke et al. 2009; Image from Meniscus Tears, Noyes & Barber-Westin)

15. Radial Tear

16. Radial Tear

17. Tear Pattern - Meniscal Root Tears
• 9 fresh frozen cadaver knees
• Axial load of 1000N at 0, 30, 60, and 90 degrees
• Fuji pressure sensitive film

18. Meniscal Root Tears

19. Meniscal Root Tears

20. Radial Tear Near Root

21. Radial Tear Near Root
• 6 fresh frozen knees
• 1000 N Load at 0, 30, 45, 60, and 90 degrees
• Intact, Root avulsion, radial tear, and repair of each
• Tekscan sensors

22. Radial Tear Near Root

23. Radial Tear Near Root

24. Malalignment
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25. Concomitant Injury
• Concomitant Injury
– Meniscal repairs tend to heal better in association
with ACL reconstruction
• Stabilization of the knee decreases microtrauma
• Marrow elements introduced into the joint

26. Concomitant

27. Failure to Address Instability
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Trojani, KSSTA, 2011

28. Meniscus Repair - Outcomes
• 2012 systematic review of 13 studies (minimum 5 year follow-up)
• Pooled failure rate was 23% (or survival was 77%)
• Medial meniscus failure rate (24%) greater than lateral meniscus (20%)
• Failure rate similar between non weight bearing (25.7%) and partial
weight bearing (21.7%)
• Failure rate similar between immobilization (23.7%) and early motion
(22.7%)

29. Meniscus Repair - Outcomes
• Limitations:
– Variety of tear patterns and locations
– Variable population
– Missing information

30. Meniscus Repair - Outcomes
• 2012 systematic review of 19 studies
• 311 relevant patients (139 inside-out, 172 all inside)
• Pooled failure rate 17% for inside-out, 19% for all-inside
• Lysholm 88 for inside-out, 90 for all-inside (MCID 10)
• No difference in Tegner activity levels

31. Meniscus Repair - Outcomes
• Shorter operative time for all-inside (not quantifed)
• 9% nerve irritation in inside out versus 2% for all-inside
• Unable to quantify differences in chondral damage or scuffing
• Heterogenous studies
• No cost analysis

32. Acute Tears, Young or Old Patients
• Patients <40 and >40 improved similarly after meniscus repair
• Failure rate at minimum of 10 years ~5% in both groups

33. Meniscus Repair
• 293 Patients Patients <20 years old, single institution
• 129 primary repairs, 149 meniscectomies, 46 discoid saucerizations
• Mean follow-up 40 months (19-62 months)
• 13% revision rate
– Primary Repair Group = 18% Revision Rate
– Bucket Handle = 47% Revision Rate
– 76% were acute reinjury, 77% within one year

34. Repair vs. Meniscectomy
If 10% of meniscectomies changed
to repairs, would save $43 million
• Repairs may fail
more, but still more
cost effective
• Improves Outcomes
• Decreases overall
costs of treatment

35. Summary – Prognostic Indicators

36. Summary – Prognostic Indicators
• Success rate of repairs reported between 76-94%
• Repair more cost-effective
• Tear-specific
– Posterior radial tears = total menisectomy
– bucket handle = 47% failure of repair
• Patient-specific
– Older patients have less healing response, but can be less
functionally demanding
– Studies are mixed, results probably equivalent
• Injury-specific
– Chronic, degenerative tears = nonop
– ACL recon = improved healing, more repairable patterns

37. Thank You
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