Advances in implant materials, fixation methods and the use of
conservative rehabilitation have resulted in greater tuberosity healing.
“There are fewer indications for humeral head replacement because
we have these better percutaneous options,” Evan L. Flatow, MD, said
during his presentation at Orthopedics Today Hawaii 2012.
Improved stems, positioning
Prosthetic stems now have more space for tuberosities and some are made
of ingrowth materials such as tantalum or have “little spikes” that
hold the tuberosity, Flatow said. He cited a study by Krishnan and colleagues
in which patients who underwent proximal humeral hemiarthroplasties with
fracture-specific stems showed greater healing and function in their injured
shoulders compared to patients who did not receive fracture-specific stems.
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Evan L.
Flatow
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Surgeons also have better methods to ensure correct positioning of the
head.
“If you put the tuberosity too far distally, you will tension the
cuff around the head and cause a tendency for that tuberosity to pull
off,” Flatow said. “[If] you put it too high, you may get impingement
and will also not have a good surface for healing.”
Flatow uses a “jigsaw puzzle method,” in which he uses the
fractured head to choose an anatomic replacement of the same size and
curvature, reconstructs the fractured humerus to see the height of the native
head above a shaft landmark, and then sets the prosthetic head at the same
height.
“You are only going to be off by a few millimeters,” Flatow
said. “Whereas in the old days, we would simply take the shaft and just
play around with trying to put a stem on it and try to figure out the height.
This is a much more straightforward way of doing it.”
Malposition also affects tuberosity healing, Flatow said. He cited a
2002 study conducted by Pascal Boileau, MD, and colleagues in which 33 of 66
patients showed malpositioning as a result of excessive height or retroversion
of the prosthesis. This lead to superior migration of the prosthesis, stiffness
or weakness, and persistent pain.
In cases of excessive retroversion, orthopedists must bring arms into
internal rotation in a sling position, which puts pressure on the tuberosity
and “knocks it off,” he said.
“Moving toward a more anatomic retroversion and fracture situation
can actually unload the greater tuberosity and make it less likely to pull off
as time goes on,” Flatow said.
Rehabilitation, fixation
Surgeons once used sutures during fixation that “came down to the
shaft,” which overreduced the tuberosity and made the shoulder stiff. Now,
some use cerclage wires around the medial side of the prosthesis. Flatow warned
that too many suture may strangulate the blood supply to the soft tissues.
“You want to construct [where] there is not much exposure, but you
have not stripped everything. You have living tissue, and yet, you have the
secure fixation,” he said.
Flatow recommends using cables instead of wires because they do not tend
to break and achieve a more stable fixation. However, he warned not to use them
in elderly patients with osteoporotic, comminuted tuberosities.
More conservative rehabilitation instead of “immediate aggressive
motion” after a few weeks of healing may also assist with tuberosity
healing, Flatow said.
“I think greater tuberosity healing can be approached
systematically,” he said. “We are certainly better than we were 10 to
15 years ago.” – by Renee Blisard
References:
- Flatow EL. Tuberosity, tuberosity, tuberosity! How to get them to
heal in HHR. Presented at Orthopedics Today Hawaii 2012. Jan. 15-18.
Wailea, Hawaii.
- Boileau P, Krishnan SG, Tinsi L, et al. Tuberosity malposition and
migration: Reasons for poor outcomes after hemiarthroplasty for displaced
fractures of the proximal humerus. J Shoulder Elbow Surg. 2002;
11(5):401-412. doi: 10.1067/mse.2002.124527.
- Krishnan SG, Reineck JR, Bennion PD, et al. Clin Orthop Relat
Res. 2011; 469(12):3317-3323. doi: 10.1007/s11999-011-1919-6.
For more information:
- Evan L. Flatow, MD, can be reached at Mt. Sinai Medical Center, 5
E. 98th St., 9th Floor, New York, NY 10029; 212-241-8892; email:
evan.flatow@msnyuhealth.org.
- Disclosure: Flatow receives royalties from Zimmer and
Innomed.