June 20, 2024

Bone bank is used for the storage of bone that needs a large amount of bone following bone loss or following different surgeries.

Bone bank

Uses of bone bank

  • Convenient to the surgeon
  • Decrease operative time for the patient
  • Decrease blood loss
  • Decrease operative trauma
  • Decrease donor site morbidity

Indications

  • Patients who need large amounts of bone or in whom autologous bone has been harvested previously
  • When a small amount of the bone is needed and scarring at the donor site might be greater than that at the recipient site

In Orthopedic Surgery

  • Revision arthroplasty of hip and knee
  • Difficult nonunion
  • Arthrodesis of knee/ spine
  • Difficult major primary fracture in osteoporosis bone
  • Large bone cyst/ residual bone defect after tumor excision

Bone Bank Protocol

5 Components:

  1. Organization
  2. Donor selection
  3. Documentation
  4. Storage and Processing
  5. Implementation

Donor Selection

Following Hip replacement:- Orthopedics surgeon request patient for his permission to store any removed tissue for donation

General Exclusion Criterias:

  • No permission from the patient
  • Under age (< 18 years), Old age (>80 years)
  • Acute/ Recent systemic infection or sepsis
  • Past history of TB
  • Recent (4 weeks) vaccination with the live vaccine
  • Rheumatoid arthritis
  • Connective tissue disorder/ Autoimmune disease
  • Malignancy
  • Donor selection exposed to radiation
  • Chronic medication especially steroid

Specific Exclusive Criterias:

  • Positive serology: HIV, HbsAg, HTLV, VDRL, RPR
  • Homosexual lifestyle
  • IV medication/ Narcotics use currently or in past
  • Hemophilic patient administered with clotting factor concentrate

Storage and Processing

  • Biopsy of 1 cm3 cortico-spongious bone, capsule, and regional lymph nodes taken for histological examination to exclude malignancies, infections, etc.

Processing

Fresh allografts

  • Are used for osteochondral allografting
  • Have to be implanted with/ without waiting result of culture and tests for late seroconversion for HIV

Fresh Frozen Allografts

  • First washing blood and marrow
  • Storage at very low temperature (-20° to -170°C) usually (-70°C to -80°C)

Advantages of Frozen Allografts

  1. The simplicity of its preparation for storage
  2. High axial load bearing strength
  3. Decrease immunogenicity

Disadvantages of Frozen Allografts

  1. Need to keep graft continuity frozen at a very low temperature
  2. Freezer continuity is monitored to avoid spoilage of graft
  3. Freezing along does not destroy all viruses and bacteria (Needs secondary sterilization)

Freeze-dried bone allograft

  • Involves removal of water from frozen tissue by sublimation in Vaccum
  • Advantages:
    • Storage at room temperature
    • Long self-life
    • Easy transport
  • Disadvantages:
    • Time-consuming
    • Altered mechanical property

Demineralized bone

  • Chemo sterilized, antigen extracted, surface demineralized autolyzed allogenic bone prepared from diaphyseal cortical bone
  • Lacks structural strength
  • High rate of resorption after grafting

Secondary sterilization

  • Gamma radiation (25 Gy from cobalt -60)
  • Irradiating at low temperature
  • Ethylene oxide sterilization

Growth Modulation

Growth Modulation is the modulation of the growth of bones in a number of ways especially done in skeletally immature bones in bone deformity.

Hueter-Volkmann Law

  • Mechanical compression slows longitudinal growth in the growth plate
  • Sustained distraction produces increased growth but the compression effect is greater

Growth Modulation

  • Treatment of some childhood deformities such as angular deformities or length discrepancies is based on the concept of mechanically suppressing growth effect

Indications

  • Skeletally immature patient with significant and symptomatic angular deformity
  • Genu valgum/ Varus
  • Angular deformity
  • Limb Length Discrepancy (LLD)
  • Scoliosis

History

  • Blount (1949):- Epiphyseal stapling
  • Steven (2007):- Extraperiosteal nonlocking plate
  • Tension band
  • Non-rigid
  • One plate/ Physis
Growth Modulation
Growth Modulation
  • Metaizieau (1998):
    • Cannulated screw for distal humerus and proximal tibia epiphysiodesis (At least 4 threads across physis)

Complication

  • Permanent closure of the growth plate

See also: Bone grafts and bone morphogenic proteins

See also: Principles of Limb Salvage Surgery