To The Editor:
We read with interest "Missed Posterior Fracture-Dislocation
of the Humeral Head. A Case Report with a Fifteen-Year Follow-up
After Delayed Open Reduction and Internal Fixation" (81-A: 708-710,
May 1999), by Kaar et al. This case report appears to be important
in demonstrating that open reduction and internal fixation in the
presence of nearly complete devascularization of the humeral head
does not always lead to what is considered inevitable avascular
necrosis and sequential collapse.
Kaar et al., however, did not include in their references the
study by Neer2, who made the salient
observation that adequate attachment and contact are generally found
in patients who have a posterior dislocation accompanied by fracture
of the humeral anatomical neck. This adequate contact has also been clearly
demonstrated, on computed tomograms, by other authors1,4,5. In our study of ten such cases,
except for one patient whose humeral head was completely detached
from the soft tissue, the fractured humeral head in all patients
remained in contact with the posterior part of the greater tuberosity,
forming a hinge3. In addition,
a triangular metaphyseal fragment was attached to the inferomedial
portion of the fractured humeral head in all patients, which was
also observed in Figures 1 and 3 in the report by Kaar et al. Avascular
necrosis with subchondral collapse occurred in only one case. Therefore,
we believe that blood flow from soft tissue attached to the hinge
and the metaphyseal fragment appeared to be maintained in most of the
fractured humeral heads and that it also facilitated rapid revascularization.
It is always difficult to gain and confirm accurate reduction
of a fracture in patients with this type of injury. In the case
reported by Kaar et al., reduction of the fracture may have been
somewhat incomplete. Resultant widening of the mediolateral diameter
of the proximal part of the humerus might thus have resulted in
subacromial impingement, causing pain and the popping sensation.
We are able to estimate this occurrence from the spur formation
of the anterior part of the acromion and the greater tuberosity observed
in Figure 4-A. To gain and secure accurate reduction, we strike
the olecranon to impact the anatomical neck fracture in conjunction with
elevation of the shoulder in the scapular plane following reduction
of the dislocated humeral head into the joint. Pressure generated
by the rotator cuff is applied to the surface of the anatomical
neck fracture after reduction, leading to stabilization of this
fracture. Internal fixation is therefore not essential to the treatment.
Moreover, it may prevent the fracture from being reduced spontaneously
by pressure generated by the rotator cuff when fracture reduction
is incomplete.
Kiyohisa Ogawa, M.D.
Atsushi Yoshida, M.D.
Wataru Inokuchi, M.D.
Corresponding author: Kiyohisa Ogawa, M.D.
Department of Orthopedic Surgery, School of Medicine Keio University,
35 Shinanomachi, Shinjuku
Tokyo 160-8582, Japan
T. K. Kaar, M. A. Wirth, and C. A. Rockwood, Jr., reply:
We welcome the comments of Ogawa et al. on this topic. We did
not include Neer's observation that adequate attachment and contact
are found, given the fact that Neer's paper was concerned with the
indications for and the operative technique of humeral head hemiarthroplasty
and did not include follow-up of specific cases with analysis of
the outcome. With respect to the paper by Ogawa et al., we find
it difficult to decipher how many cases were truly comparable with
the ones that we presented, given that they classified the fractures
according to Neer's system but had one one-part posterior fracture-dislocation.
In our report, we sought to highlight a number of points regarding
such a case, including the need for vigilance in the diagnosis,
appropriate investigation, and the benefit of appropriate treatment as
evidenced by the unique long-term follow-up information.
In principle, we would favor open reduction of these injuries
rather than attempted closed reduction in the first instance.
T. Kenneth Kaar, M.D.
Michael A. Wirth, M.D.
Charles A. Rockwood, Jr., M.D.
Corresponding author: Michael A. Wirth, M.D.
Department of Orthopaedics
University of Texas Medical School and Health Science Center
7703 Floyd Curl Drive
San Antonio, Texas 78284-7774