Wednesday, September 17, 2014

Shoulder hemi-arthroplasty for humeral head avascular necrosis

The following case is a middle aged patient with shoulder pain for several years. The radiographic evaluation of the shoulder demonstrated post-collapse avascular necrosis of the humeral head. The cause of his disease was alcohol abuse. While some surgeons believe that a "minimallly invasive" procedure is appropriate for the treatment of this condition we avoid the use of such procedures because:
(1) mini caps have the problem of loosening and do not prevent further progression of the disease

(2) shoulder resurfacing implants result in early loosening and revision to hemi-arthroplasties.

The longevity of a hemi-arthroplasty is approximately 10 years before glenoid wear becomes an issue. At that point a conversion of the hemi-arthroplasty to a total shoulder replacement can be offered extending the longevity to an additional 10-15 years.  Preop/postop radiographs and intraoperative images are shown below


Severe loss of cartilage from AVN



Tuesday, September 9, 2014

Type I-II-III-IV pediatric supracondylar humerus fractures

The majority of pediatric supracondylar humerus fractures are extension type injuries. Fixation of these fractures requires attention to detail and avoidance of use of medial pinning when possible. Use of medial pins runs the risk of injury to the ulnar nerve and there is no additional biomechanical stability by adding medial pins. Gartland classified these fractures in 3 types based on the displacement and treatment method.

Gartland Classificaiton 
Type INondisplaced, beware of subtle medial comminution leading to cubitus varus
Type IIDisplaced, posterior cortex intact
Type IIICompletely displaced
*Type IVComplete periosteal disruption with instability in flexion and extension

Type I fractures can be treated in a long arm cast or with pinning. Some orthopaedic surgeons prefer pinning of the non displaced  Type I fractures in an attempt to avoid lost to followup cases, avoid frequent visits to the office and radiation exposure. Currently, both methods of treatment are acceptable as long as a close weekly followup is scheduled for the patients that receive conservative Rx in a cast without pinning. If the fracture displaces then pinning is required. 

The case below is a 4 year old patient who presented with elevation of the fat pad on the lateral view due to a non displaced supracondylar humerus fracture. She was treated in a long arm cast for 6 weeks and healed without complications.




The following case is a 3 year old patient who presented with a Type II supracondylar humerus fracture that was treated with 2 lateral pins. The fracture healed without complications at 6 weeks.










The last case is a 4 year old patient who presented with a Type III supracondylar humerus fracture and was treated with lateral pinning only. The patient had the pins removed at 3 weeks and received long arm cast immobilization for a total of 6 weeks. Xrays show a healed fracture at 6 weeks.







XRs 6 months after show healed fracture. XRs are shown below at 6 months after surgery.



During fixation of these fractures it is ideal to have tricortical fixation by penetrating the coronoid fossa with the pins as demonstrated in the picture below.



This method of fixation provides better biomechanical and rotational control of the fracture. It is important to take into consideration the 3 column theory and private stability to the three columns of the distal humerus.
In addition, after the placement of the pins the stability of the fixation must be tested with "live" fluoroscopic evaluation of the fracture with flexion and extension of the joint.

The AAOS published practice guidelines for the treatment of these fractures that can be found by a clicking here