3. INTRODUCTION
• INDUCED MEMBRANE TECHNIQUE
• Masquelet’- 1986, first case series in 2000
• 2 step procedure for boe defects and non
unions.
4.
5. The Masquelet technique- Two staged
• At the first operation,
– Radical soft tissue and bone debridement
– (PMMA) cement spacer is implanted at the site of the bone
defect
– Limb is stabilised with an external fixator.
– soft tissue envelope is repaired .
• The cement spacer has two roles.
1. Mechanical - Prevents fibrous tissue invasion
2. Biological - Induction of the surrounding membrane that will
revascularise the bone graft and prevent its resorption.
6. The Masquelet technique- Two staged
• At the second stage,
– 6–8 weeks later
– the cement spacer is carefully removed
– the formed ‘‘induced membrane’’ is minimally disturbed
– defect is filled with morcellised cancellous autotlogous bone
graft (with additional bone graft substitutes, 1:3)
– Bone is stabilized.
7. • INDUCED MEMBRANE- The pseudosynovial membrane
– formed around the cement spacer (as a foreign body
reaction- first stage)
– acts as a chamber around the bony defect to contain the
bone graft and stimulate bone regeneration (second stage).
• Induced membrane becomes highly vascularised
• Growth factors
– VEGF
– TGF-beta 1
– BMP-2.
• prevents resorption of cancellous bone graft and
• positive effect on consolidation of the defect.
8.
9.
10.
11. Keys for good outcome- Stage 1
1. Thorough debridement and irrigation
2. Edges of the bone fragments should be healthy with a viable
bleeding .
3. Appropriate fixation of the bone defect
– Temporary external fixator
4. Meticulous pin site care
5. Cement should be placed inside the canal and over the edges
6. Soft tissue envelope should have adequate blood supply.
12. 7. Cement spacer loaded with antibiotics- INU
8. Good soft tissue coverage is essential
– free tissue transfer may be required.
9. Wound closure must not be under tension.
13.
14.
15.
16. Keys for good outcome- Stage 2
1. CULTURE prior to administration of antibiotics intra-
operatively.
2. Membrane must be incised with caution
3. The cement spacer is removed with a saw or an osteotome
4. The IM canal is prepared with hand reamers or a curette
5. All non-vital tissues must be removed.
6. Depending on the size adequate volume of graft material
should be available.
17. 7. Autologous bone graft can be obtained from the iliac crest or from
the intramedullary canal using the Reamer/Irrigator/Aspirator (RIA)
8. For large defects, can be augmented with allograft or bone
substitutes
9. Bone graft material can be enhanced with osteoprogenitor cells
(from bone marrow aspirate) or with osteoinductive growth factors
(commercially available BMPs.)
10. The membrane must be closed to ensure that the graft material is
contained into the chamber
11. Adequate mechanical stability must be provided
12. Soft tissue coverage should be adequate and wound closure
should be performed without tension.
18.
19.
20.
21.
22. INDICATIONS
• Bone defects secondary to
– Chronic osteomyelitis
– Tumour excision
– Traumatic bone loss
– Septic non union
– Aseptic non-unions
24. ADVANTAGES
• Induced membrane plays an important role in
revascularisation and bone formation and consolidation
• Cancellous bone graft can be used even if the recipient site
has initially been irradiated or infected or in cases of
malignancy
• The graft can be augmented with cells, growth factors,
allograft or other bone substitutes depending.
• Length of the defect is maintained.
25. DISADVANTAGES
• Two different interventions.
• Availability of the autograft
– Limited
– Donor site morbidity
• Supplementary procedures for soft tissue transfer
26.
27. • 628 papers were identified
• Age >15 years
• Follow up > 12 months
• 17 studies, 427 patients
28. FIGURES
• Mean age -39 years ( 15-84)
• Males – 82.7 %
• Mean follow up – 16 months ( 6-264)
• Tibia – 67.2 %, Fibula- 12.9 %, Femur – 19.4 %
• Metaphysis – 62 %
29. • Mean defect – 5.53 cm ( 0.6 to 26 cm )
– < 2 cm - 15
– 2-5 cm - 99
– 5-10 cm - 114
– 10 cm - 61
• Antiobiotics – 62.5 %
• External fixator- 36.8
• Soft tiisue construction – 36.5 %
31. COMPLICATIONS
• 49.6 % ( 15 to 100 % )
• Superficial SSI – 4.9 %
• Deep – 4.4 %
• Failure ( infection or non union ) – 18 %
– Non union of graft
– Failure of graft maturation
– Resorption of graft
– Refracture
• Another intervention – 26.7 %
34. COMPARISON
• Healing time is independent of the length.
• Better accepted as exernal fixators can be
avoided.
• No micrsurgical intervention .
• Less ressitant to torsional and bending forces.
35. LIMITATIONS OF THE STUDY
• Failed to look in to the comorbidities of the patients
– Diabetes mellitus
– Peripheral vascular disease
– Immunocompromised condtions
– Malignancy
• Failed to compare the follow up time and size of the
defect
• No distinction between infected and non infected
• Majority are retrospective studies.
Moreover, as the spacer behaves as a foreign body, absence of infection after two months is an excellent witness of adequate local conditions for bone grafting.