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ASES Specialty day 2009

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ASES Specialty day 2009 Powered By Docstoc
					Highlight from the 76th AAOS
   Annual Meeting 2009
       Sports Medicine




      Nadhaporn Saengpetch
        Division of Sports Medicine,
       Department of Orthopaedics,
 Faculty of Medicine Ramathibodi Hospital,
             Mahidol University
       AOSSM



AANA                  ASES




               AAOS
   Improving results of rotator cuff
surgery: Patient selection, techniques,
            rehabilitation
  The influence of distinct anatomical subregions
  of the supraspinatus on humeral rotation
  (Jeffrey J. Gates, VA Healthcare System & UC Irvine, CA)
• 14 cadaver shoulder specimens
• Anterior fiber  internal rotation (IR)
• Posterior  induced external rotation (ER) in some
  abduction angle
• Scapular plane: anterior  acts both IR or ER depends
  on the initial humeral position
  posterior  never acted as IR
• a distinct functional difference between the anatomic
  subregion
• SSP has no longer simple ER function but IR too
The influence of distinct anatomical subregions
of the supraspinatus on humeral rotation
(Jeffrey J. Gates)
  Effect of double row fixation on rotator cuff
  tendon blood flow
  (John J. Christoferetti, Steadman Hawkins Clinic of the Carolonas,
  Spartanburg, SC)
• A pilot study of 5 pts repair with suture bridge
  technique (PushLock)
• Using a custom laser Doppler flow metry probe
• 40% significantly decline in the blood flow
  present after the second row implants are added
• it is evident based on this initial analysis that
  double row fixation provides increased fixation
  strength at the cost of blood flow
  rhPDGF-ββ coated sutures enhance rotator cuff
  repair in a sheep model
  (Christopher Uggen, Kerlan-Jobe Orthopaedic Clinic, LA, CA)
• #2 Fiberwire suture were coated dip-coated in a
  collagen-rhPDGF-ββ solution and confirmed with ELISA
• FTRCT were created in 14 sheep & immediate repair
• Perform the necropsy
• Histological analysis revealed improved recreation of the
  tendon to bone interface
• Biomechanical testing revealed no significant difference
  in the ultimate load to failure
  Effect of matrix metelloproteinase inhibition on
  tendon-to-bone healing in a rotator cuff repair
  model (Asheesh Bedi, HSS, NYC, NY)
• 62 male Sprague-Dawley rats  detachment of the
  supraspinatus from its insertion and immediate repair
  using non-absorbable suture and bone tunnel fixation
• recombinant alpha-2-macroglobulin (A2M) protein was
  applied
• sacrificed at 2 and 4 weeks for histomorphometric and
  immunohistochemical analysis
• Increased fibrocartilage interface tissue and improved
  collagen organization in the healing enthesis of the A2M-
  treated repairs may reflect enhanced healing
    Natural history of infraspinatus fatty infiltration
    in rotator cuff tears
    (Barbara Mélis, The CORE Institute Phoenix, AZ)
• MRI or CT-arthrogram of 1688 pts with RCR
• SSP 93.7%, SSC 37%, ISP 24%
• Goutallier grading system for ISP
• Type, sex, side, traumatic cause, delay between the
  onset of symptoms and imaging studies and age of pts
  at imaging
• The larger tears, longer delays after tendon rupture, and
  older age are associated with more severe and frequent
  fatty infiltration
• Stage 2 fatty infiltration appears at average of 2.5 years
  after the onset of symptoms and the repair should be
  done within this time frame
   Fatty infiltration of the supraspinatus –
   A reliability study
   (Matthew D. Williams, Centre Orthopédique Santy, Lyon, France)
• 3 trained shoulder surgeons  reviewed 87 CT scan of
  the RCT in 3 different times
• Reviewed 3 planes: axial, coronal, sagittal
• Axial  highest level of agreement of both intraobserver
  and interobserver values
• 3-tiered system had greater agreement than the 5-tiered
• ‘Tangent sign’  excellent agreement for all reviewers,
  related to the presence of at least grade 3 fatty infiltration
  (useful for clinical decision making)
• ‘Fish backbone sign’  reliable and objectively standard
  for grade 3 infiltration
Arthroscopic suprascapular nerve (SSN) release in retracted rotator cuff tears: A
prospective with preoperative and postoperative EMG

(Laurent Lafosse, Alps Surgery Institute, Clinique General , Annecy, France)

    • A prospective cohort series of 51 pts who had
      arthroscopic SSN decompression in massive RCT
    • A pre- and post-operative EMG (70% were found
      entrapment preoperatively)
    • The prevalence of SSN entrapment with large and
      massive rotator cuff tears may be under appreciated
    • This clinical entity suggests it may be an important factor
       in the treatment of retracted rotator cuff tears
  Complete removal of muscle load is detrimental
  to rotator cuff healing
  (Leesa M. Galatz, Washington University, St. Louis, MO)
• Botox-A was injected to remove the mechanical load
  (control=NSS injection)
• Animal models (rat), a transosseous bone tunnel repair
• All load is removed, the cross-sectional area and the
  structural properties are decreased in the Botox group
                       56 days
   Complete removal of muscle load is detrimental
   to rotator cuff healing
   (Leesa M. Galatz, Washington University, St. Louis, MO)
• Ultimate strength and tangent modulus  no significantly difference
             21 days                     56 days




• Providing the proper load environment has clinical implication in
  terms of immobilization and rehab protocols after surgery
• Paralyzing SSP to minimized the tendon pull-off may be detrimental
  to RCR if coupled with sling immobilization
  Latissimus dorsi tendon transfer in irreparable
  rotator cuff tears – A modified technique for
  reduction of failure incidence
  (Herbert F. Resch, General Hospital Salzburg, Austria)
• 42 pts (average age 58 yrs), 20=bone block graft,
  22=sharp tendon cut
• A bone chip at humeral insertion, 47 mo. F/U
• Constant, ASES score, plain x-ray, MRI
• Harvesting the tendon with a wedge of bone enables
  direct bone-to-bone transosseous fixation
• Higher stability of the transferred tendon is achieved and
  significantly reduces the incidence of graft rupture
Trauma
  Biomechanical comparison of a modified Weaver-Dunn and a
  novel free tissue graft reconstruction of the coracoclavicular and
  acromioclavicular ligamentous complexes
  (Michael G. Michlitsch, VA Healthcare System and UC Irvine, CA)
• 6 cadavers, W-D and contralateral side with the new free
  graft technique (looped btw coracoid pr. and clavicle)
• AC recon.  an extra-articular fiberTape securing a
  doubled tendon graft placed in an intramedullary fashion
  across the ACJ
• Compared compression load, translation (A-P, S-I) load
  between pre-operative and post-operative
• Free tissue graft demonstrates initial stability similar to
  that of intact specimens and significantly greater than the
  stability of a modified Weaver-Dunn
  Functional outcomes after treatment of proximal
  humeral fractures with the use of locked plating and
  supplement tension band fixation
  (Mark Mighell, Florida Orthopaedics Institute Research Foundation, Tempa)
• Multicenter retrospective study, 80 pts
• Neck-shaft angle, radiographic union, hardware failure
  and AVN
• ASES score, 1 yr F/U
• predictable fracture union and favorable functional
  results with using TBW
• Problem of varus collapse and hardware failure
  neutralize the deforming forces with TBW benefit
  Biomechanical evaluation of parallel versus orthogonal
  plate fixation of distal humerus fracture using two
  different testing condition
  (Charalampos G. Zalavras, VA Healthcare System and UC Irvine, CA)
• 10 matched pairs fresh frozen cadavers
• Created a low T-type distal humerus fx with a 10 mm
  metaphyseal defect
• Orthogonal plating (Medial and posterior) vs. Parallel
  plating (medial and lateral)
• Acumed congruent elbow plate system
• Cyclic loading and load to failure (varus & axial load)
   Biomechanical evaluation of parallel versus orthogonal
   plate fixation of distal humerus fracture using two
   different testing condition
   (Charalampos G. Zalavras, VA Healthcare System and UC Irvine, CA)




• Parallel plating  higher stiffness in varus cyclic loading but similar
  stiffness in axial cyclic loading
• No significant difference in the load to failure properties
• Screw loosening in all posterior plates of the orthogonal
  construct for the varus loading
   Periprosthetic fracture after shoulder
   arthroplasty, a meta-analysis
   (Anthony W. Frisella, Beth Israel Medical Center, NY)
• 8 included studies, 44 pts, only humerus!!
• Age, Wright-Cofield classification, treatments, time to
  union and outcome
• 3 groups: non-operative, ORIF & revision
• High healing rate but long time to heal
• Non-operative treatment is warranted before considering
  surgical intervention (no union time conferring)
• Fracture classification did not affect outcome
Instability: Bone grafts and
       complications
  What is the stabilizing mechanism of the
  Latarjet procedure?
  (Nobuyuki Yamamoto, Tohoku University, Sendai, Japan)
• Sling effect=SSC, bone block effect=coracoid process
• To find the precise contribution of each mechanisms
• 8 fresh frozen cadaveric shoulders, skin, subcutaneous
  tissue and deltoids were removed
• Two arm positions at 60º of abduction and maximal ER
  (end-range) and neutral rotation (mid-range)
• End-range: 81% of stability anterior capsular complex
  repair
• Mid-range: 82% of stability  reconstruction of the
  glenoid concavity
    Normalization of glenohumeral articular contact pressures after
    either Latarjet or iliac bone grafting procedure: impact of graft
    type, position and coracoid orientation
    (Matthew T. Provencher, Naval Medical Center, San Diego, CA)

• Proud vs.flush of Latarjet / IBG
• Optimal orientation of the graft (lat./ inferior?)
• 12 fresh-frozen cadaveric shoulders
• Intact glenoid, 15% & 30% loss from 2-6 o’clock
• The proud Latarjet-LAT provided higher contact pressure
  and also shift the articular contact forces to the postero-
  inferior quadrant
• favor the potential utility of optimally placed ICBG and
  Latarjet-INF and flush fashion
Reverse prosthesis: Recognizing and
      treating complications
  A radiographic analysis of the effect of glenosphere
  position and prosthetic design on scapular notching
  following reverse total shoulder arthroplasty
  (Laurence B. Kempton, William Beaumont Hospital, Royal Oak, MI)
• 161 RSA (Delta-III), x-ray follow-up 12 months
• Implant the glenosphere base plate in inferior tilt vs.
  parallel to the native glenoid surface
• Different neck-shaft angle (142º vs. 155º)
• Placing the base plate low on the face of glenoid, an
  inferior tilt of the glenosphere and using a smaller neck-
  shaft angle  significant reduced the rate and grade of
  scapular notching
     Instability after reverse shoulder arthroplasty
     (Ryan T. Bicknell, University of Washington, Seattle, WA)
•     Multicenter case series,13 surgeons
•     Pts: M=26, F=17 (age 36-83 yr.)
      Causes of dislocation
1.    Insufficient passive tension in the soft tissue
2.    External force overwhelm an appropriate compressive
      force
3.    A-P soft tissue are not intact, allow excessive rotation
      beyond the range of stability
4.    Deltoid deficiency + IR/ER muscle defects
5.    suboptimal / insecure position of the components
6.    Unwanted contact takes place btw the jt. surface,
      interposed tissue
Technical pearls to improve total
       arthroplasty results
  Posterior glenoid bone grafting in TSA for posterior
  glenoid wear: technical and radiographic outcome
  (Gregory P. Nicholson, Rush University Medical Center, Chicago, IL)
• Posterior glenoid wear results in increased retroversion
  and possible posterior HH subluxation
• Posteroir bone graft from HH is useful
• Axillary view: 1 wk, 3 mo, 6 mo and 1 yr
• PGBG was faced up, used a pegged cemented PE
  glenoid
• The retroversion was corrected to avg. of -4º
  Radiographic comparison of pegged and keeled
  glenoid components using modern cementing
  techniques: a prospective randomized study
  (Joanne E. Labriola, Texas Orthopaedic Hospital, Houston, TX)
• Evaluated the effect of glenoid design on the immediate
  and mid-term radiographic lucency
• No significantly less glenoid lucency in the immediate
  post-op
• A pegged glenoid had significantly less lucency than a
  keel after avg. F/U of 28 mo.
• Pegged component remains radiographically superior to
  keeled
Radiographic comparison of pegged and keeled
glenoid components using modern cementing
techniques: a prospective randomized study
(Joanne E. Labriola, Texas Orthopaedic Hospital, Houston, TX)

      Immediate postop.                       F/U avg. 28 mo.
Posters
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