MIROS (Minimally Invasive Reduction and Osteosynthesis System MIROS consists of four 2.5 mm thick and 50 cm long stainless steel or titanium wires the end of which is introduced into a metallic clip. Assumed that the MIROS might provide greater fracture stability and less complications with respect to traditional percutaneous pinning (TPP).

1. Percutaneous pinning of three or four-part
fractures of the proximal humerus in
elderly patients
in poor general condition:
MIROS® versus traditional pinning.
DR. ARPAN CHAUDHARY
Stefano Carbone & Mario Tangari & Stefano Gumina &
Roberto Postacchini & Andrea Campi &
Franco Postacchini
International Orthopaedics (SICOT) (2012) 36:1267–1273

2. ❑ The proximal humerus comprises four major parts (corresponding
to the four developmental ossification centres).
1. Anatomical head
2. greater tuberosity : site of insertion of three of the supraspinatus, infraspinatus and
teres minor.
3. lesser tuberosity : site of insertion of the remaining rotator cuff muscle, subscapularis.
4. shaft.
❑ The head is directed
predominantly medially,
superiorly by 130° and
anteriorly by 30°.
❑ The anatomical head and the
tuberosities make up the surgical
head of the humerus.
❑ The surgical neck of the humerus
lies at the junction of the surgical
head and the shaft.

3. ❑ The deltoid arises from the scapula and
clavicle and inserts into the deltoid
tuberosity.
❑Pectoralis major and teres major insert into
the lateral and medial edges of the bicipital
groove respectively.
Ligaments :
1) Coracohumeral ligament.
2) SGHL - Restraint to inferior
translation at 0° degrees of
abduction (neutral rotation).
3) MGHL - Resists AP translation in the
midrange (~45°) of abduction.
4) IGHL - Restraint to AP
translation at 90° degrees of
abduction

5. Proximal Humerus Fractures
Epidemiology
Incidence
- 4-6% of all fractures
- third most common non-vertebral fracture pattern seen in the elderly.
- two-part surgical neck fractures are most common.
Demographics
- 2:1 female to male ratio
- increasing age associated with more complex fracture types
Risk factors
- osteoporosis
- diabetes
- epilepsy
-female gender
Mechanism : Low-energy falls in elderly with osteoporotic bone
: High-energy trauma young individuals

6. PATHOANATOMY :
vascularity of articular segment is more likely to be preserved if ≥ 8mm of calcar is
attached to articular segment.
Predictors of humeral head ischemia (Hertel criteria) :
<8 mm of calcar length attached to articular segment
disrupted medial hinge
increasing fracture complexity
displacement >10mm
angulation >45°
predictors of humeral head ischemia does not necessarily predict subsequent avascular
necrosiS

7. AO :

10. Non-operative :
Most fractures (90%) can usually be treated conservatively including:
• One-part fractures
• Impacted fractures of the surgical neck without severe angulation
• Two-, three- and four-part fractures with <30° angulation of the articular surface, and
good cortical contact with the shaft
• Any other fracture pattern with relevant patient factors: old age, low functional
requirements,diabetes, renal disease, alcohol abuse, psychiatric condition, dementia.

11. OPERATIVE :
❑ Absolute indications for surgery
• Fewer than 1% of fractures require urgent surgery.
These may include:
• open fractures
• fracture-dislocations
• fractures with associated vascular injury.
❑ Relative indications for surgery
Only a minority (around 10%) of fractures are likely to benefit from surgery to reconstruct or
replace the humeral head, including:
• two- or three-part fractures where the greater tuberosity is displaced by >1 cm
• ‘off-ended’ two-part fractures of the surgical neck
• two-, three- or four-part fractures where the articular surface has displaced by
>30°
• head-splitting fractures (may require a hemiarthroplasty).

12. SURGICAL TECHNIQUES :
Several reconstructive options are available:
• Percutaneous fixation.
• Open reduction and internal fixation.
• Nailing.
• Arthroplasty (Fig. 9.9): Certain fractures are not amenable to fixation due to a high level
of articular comminution or poor bone stock, particularly in elderly patients. In these
circumstances, a primary hemiarthroplasty should be considered.

13. JOURNAL CLUB

14. ❑Treatment of three- or four-part fractures of the proximal humerus in elderly patients is still
controversial. While a few studies reported that non-operative management is associated
with poor results , a recent prospective, but not controlled, trial found it difficult to demonstrate
a significant advantage of surgical over non-operative management
❑ However, the fracture pattern, amount of displacement of the fragments, bone stock of the
upper humerus, preexisting rotator cuff disease or arthrosis and the patient’s age and general
condition are important factors in the choice of treatment.
❑ Percutaneous techniques may allow displaced fractures of the proximal humerus to be reduced
and stabilised by Kirschner wires (K-wires) alone or wires clamped into a locking device.
❑The advantages of these techniques are not only the possible preservation of vascular supply to
bone fragments, but also no blood loss and the possibility of surgery under brachial plexus block.
INTRODUCTION

15. MIROS (Minimally Invasive Reduction and Osteosynthesis System®)
❑ It allows correction of angular displacement and fixation of fracture fragments by means
of elastic K-wires locked in a metallic clip placed externally on the skin.
❑ Assumed that the MIROS might provide greater fracture stability and less complications
with respect to traditional percutaneous pinning (TPP).
❑ SO, A prospective study thus carried out to compare the MIROS to TPP for the treatment of
three- or four-part fractures of the upper end of the humerus of elderly patients
in ASA PS 3 or 4.
ASA PHYSICAL STATUS CLASSIFICATION SYSTEM

16. ❑Between 2007 and 2009, ASA PS three or four was assigned to 58 consecutive patients admitted
at two hospitals of a single town for fracture of the proximal humerus.
In one hospital the patients were treated with the MIROS, while in the other TPP was
performed.
❑There were 37 women and 21 men with a mean age of 76 years (68–93), the patients of the
two groups being matched for mean age, sex, mean ASA PS score and type of fracture
MATERIALS AND METHODS :

17. Classified according to the Neer system.
In complex fractures, CT scan with 3-D was performed.
In no patients were there local vascular or neural complications
Excluded :
fracture extending to the humeral diaphysis or the articular surface of the humeral head and
those with no active motion of the arm due to previous cerebrovascular diseases.
clinical evaluation and shoulder radiographs at three, six, 12 and 16 weeks.
Of the original patients, 6 were lost to the latest follow-up ( 2 had died and 4 did not attend for
assessment), thus leaving 28 patients in the MIROS group and 26 in the TPP group.
The shoulder function was evaluated using the Constant Score (CS) method. The patients were
also asked to rate the result of surgery with the subjective shoulder value (SSV) method.

18. MIROS consists of four 2.5 mm thick and 50 cm long stainless steel or titanium wires the end
of which is introduced into a metallic clip.
The latter has a diameter of 20 mm and contains a screw that is tightened to lock the wires.
Supraclavicular brachial plexus block given. Fracture Reduced.
K-WIRES from GT, HEAD & PROXIMAL METAPHYSIS.
Bending of Kwires to lock them into the external clip, which was placed at least 2 cm from the
skin of the deltoid area.

19. Once the clip was blocked, it was possible to slightly correct the varus or valgus position of
the humeral head by compressing or distracting the K-wires into the metallic clip.
They were then cut and the screw inside the clip was tightened.
Post-operatively a sling was applied.
The MIROS was removed five or six weeks after the operation

20. TPP :
❑ TPP was performed according to the technique first described by Jaberg et al. using five
terminally threaded 2.5-mm Schanz pins.
❑ The edges of the pins were bent manually and left outside the skin. Post-operatively, patients
wore a sling for three or four weeks.
❑ The pins were removed five or six weeks after the operation.
POST-OP :
❑ In the MIROS group pendulum exercises were begun a mean of four days after surgery and
passive assisted exercises two weeks post-operatively. Passive motion was progressively
increased depending on the patient’s tolerance.
❑ In the TPP group, passive shoulder motion was started three or four weeks depending on the
type of fracture and active motion five or six weeks after surgery
Fisher’s exact test was used to compare the proportions and
Student’s t test for average values; p values <0.05 were
deemed to be statistically significant. Multiple regression
analysis was performed to identify potential associations
between dependent variables (CS and SSV) and independent
variables (type of fracture, complications).

21. 1). OPERATIVE TIME 37.3 MIN 40.1 MIN
2). FLUROSCOPY TIME 76 SECS 50 SECS
3). CS SCORE MORE+++ LESS++
4). SSV SCORE MORE+++ LESS++
5). COMPLICATION RATE 10.7 26.9
6). ROM OF MIROS IN FOLLOW UP MORE THAN TPP
7). ABDUCTION STRENGTH OF MIROS IN FOLLOW UP MORE THAN TPP
8). 1/2 PINS COME OUT PARTIALLY FROM HUMRUS IN 5 PTS – REMOVED WITHOUT LOSS OF REDUCTION
9). MIROS – 1 PT HAS MODERATE LOSS OF FRACTURE REDUCTION
10). TPP- 1 PT HAS INFECTION-ANTIBIOTICS
11). 4 PT HAS AVN – 3 DO NOT ASK FOR OPERATIVE BCZ ACCEPTABLE CONDITION
12). A STATISTICALLY SIGNIFICANT DIFFERENCE BETWEEN THE TWO GROUPS WAS FOUND
FOR OVERALL COMPLICATIONS, PIN MOBILISATION AND PIN TRACT INFECTION (P<0.05).
13). IN BOTH GROUPS, THE MULTIPLE REGRESSION ANALYSIS SHOWED THAT THE VARIABLES THAT
INFLUENCED THE CS AT THE LATEST FOLLOWUP WERE THE TYPE OF FRACTURE [THREE- VS FOUR-PART
FRACTURES (P00.03)] AND COMPLICATIONS (P<0.001).
MIROS TPP
RESULTS :

22. RESULTS :
The Subjective Shoulder Value (SSV) is a patient estimation of the function in their afflicted
shoulder, relative to their completely normal shoulder, expressed as a percentage.

24. IN CONCLUSION :
Study shows that, although TPP can be a valid treatment for three- or
four-part fractures, the MIROS gives better results.
However, both types of treatment imply closed reduction of the
fracture, which can be a very demanding procedure that may fail to
provide a satisfactory reduction, particularly in four-part injuries.
Therefore, not only in the young, but also in the middle-aged patient
with no general comorbidities, ORIF should generally be preferred to
percutaneous pinning.