Abstract
Background: Derotational humeral osteotomies have been used in older
children with brachial plexus birth palsy and glenohumeral joint deformity to
place the upper extremity in a more functional position. The purpose of this
study was to determine the effects of these procedures on shoulder function
and joint morphology.
Methods: Forty-three patients underwent a derotational humeral
osteotomy for functional impairment in the setting of internal rotation
contracture and/or glenohumeral joint deformity at our institution from 1996
to 2004. Osteotomies were performed proximal to the deltoid insertion and were
stabilized with plate-and-screw fixation. The average age of the patients at
the time of surgery was 7.6 years (range, 2.3 to 17.0 years). Shoulder
function was graded according to the modified Mallet classification system.
Glenohumeral deformity was graded according to the classification scheme of
Waters et al. The results for twenty-seven patients who were followed for a
minimum of two years (average, 3.7 years) are reported.
Results: The average amount of external rotation achieved with
osteotomy was 64° (range, 35° to 90°). The mean aggregate Mallet
classification score improved from 13 to 18 points (p < 0.01). The mean
Mallet classification scores for the individual elements similarly
demonstrated improvement following osteotomy, with the greatest gains in
hand-to-mouth, hand-to-neck, and external rotation motions. The mean
classification of the glenohumeral deformity was type IV preoperatively and
postoperatively, signifying the persistence of glenohumeral dysplasia. There
were no nonunions. One patient required a revision osteotomy for inadequate
initial correction. One patient sustained a humeral fracture distal to the
plate fixation because of sports-related trauma.
Conclusions: Derotational humeral osteotomy improves shoulder
function in patients with brachial plexus birth palsy, internal rotation
contracture, and/or advanced glenohumeral joint deformity. This osteotomy
provides an attractive treatment option for patients with brachial plexus
birth palsy who have advanced glenohumeral dysplasia precluding soft-tissue
releases and tendon transfers.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.
Brachial plexus birth palsy refers to paralysis of the upper extremity
secondary to a traction or compression injury to the brachial plexus sustained
during birth1.
Despite advances in prenatal and obstetrical care, the estimated prevalence
remains between 0.1% and 0.4% of live
births2-5.
While the majority of patients demonstrate spontaneous recovery and attain
nearly normal upper-extremity function, some have persistent neurological
deficits and functional
limitations2,3,6,7.
Patients with incomplete recovery may have functional limitations develop
because of muscle weakness and soft-tissue contractures. In patients with
upper trunk (C5-C6) involvement, weakness of the deltoid and rotator cuff
muscles limits shoulder abduction and external rotation. Furthermore, in
patients with long-standing muscular imbalance, progressive glenohumeral
dysplasia and/or joint instability may
develop8-13.
While tendon transfers have been advocated to improve shoulder function in
selected patients, intermediate-term follow-up has demonstrated no significant
improvement in glenohumeral morphology following these extra-articular
procedures14-17.
Furthermore, in patients with advanced glenohumeral dysplasia, tendon
transfers and extra-articular soft-tissue procedures may yield suboptimal
results, as the underlying joint deformity may cause continued restrictions of
abduction and external rotation.
In patients with long-standing internal rotation contractures of the
shoulder with associated joint deformity, derotational humeral osteotomy has
been proposed to improve the position and function of the upper
extremity17-23.
The purpose of this investigation was to assess the effects of derotational
humeral osteotomy on global shoulder function and glenohumeral morphology in
patients with brachial plexus birth palsy who were treated at our
institution.
All patients with brachial plexus birth palsy presenting to the Hand and
Upper Extremity Program at our institution have been prospectively evaluated
since 1993. The patients with persistent neurological deficits and functional
impairments have been treated according to an evolving surgical algorithm
taking the following factors into consideration: age, muscle strength,
soft-tissue contractures, and glenohumeral joint deformity. Patients with
shoulder adduction and internal rotation contractures and concomitant
functional limitations are evaluated with either magnetic resonance imaging or
computed tomography of the affected shoulder to assess glenohumeral
morphology. The degree of joint deformity is quantified and graded with use of
a previously published classification
system13. Patients
with rotator cuff weakness and minimal joint deformity are treated with
latissimus dorsi and teres major tendon transfers to the rotator
cuff14,15.
Patients with weakness, joint contractures, and mild-to-moderate glenohumeral
deformity deemed reducible on preoperative assessment are treated with open or
arthroscopic glenohumeral reduction, soft-tissue releases, and tendon
transfers. Patients with persistent internal rotation contractures and
external rotation weakness despite prior soft-tissue procedures and/or
advanced joint deformity are treated with derotational humeral osteotomy. This
last patient cohort is the subject of the current investigation. This study
was approved by the Committee on Clinical Investigation of our institutional
review board.
Between 1996 and 2004, forty-three patients with brachial plexus birth
palsy underwent derotational humeral osteotomy for the treatment of internal
rotation contracture of the shoulder in the setting of advanced glenohumeral
dysplasia or dislocation. Twenty-seven patients who were followed clinically
and radiographically for a minimum of two years were included in the present
study, and their findings are presented in the Appendix. Of the remaining
sixteen patients, twelve who had had the surgery within two years from the
initiation of this study were therefore unavailable for review and four for
whom more than two years had passed since the surgery had insufficient
follow-up data for inclusion in this report. Of the study patients, ten were
girls and seventeen were boys. The mean patient age at the time of surgery was
7.6 years (range, 2.3 to 17.0 years). Only six patients were operated on prior
to the age of six years. The average clinical and radiographic follow-up
period was 3.7 years (range, 2.0 to 7.8 years).
All patients underwent comprehensive preoperative and postoperative
evaluations consisting of detailed medical histories and physical
examinations. Specifically, global shoulder function was classified in all
patients with use of the modified Mallet classification system (see
Appendix)24,25.
The intraobserver and interobserver reliability of this classification system
in the grading of shoulder function in brachial plexus birth palsy has been
previously
established26. In
addition, as described above, all patients underwent preoperative magnetic
resonance imaging or computed tomography scanning of the affected shoulder to
assess glenohumeral morphology. The degree of joint deformity was also graded
according to the classification system of Waters et al.
(Fig.
1)13.
Sixteen of the twenty-seven patients obtained axial imaging of the affected
shoulder following the derotational humeral osteotomy. These follow-up
radiographic studies, which were performed as part of our institution's
ongoing prospective study protocol assessing the natural history and effects
of surgical treatment on shoulder function and glenohumeral development, were
used to assess the continued glenohumeral development or to evaluate shoulder
pain or dysfunction.
Surgical Procedure
The humerus was exposed by means of a deltopectoral approach
(Figs. 2-A and 2-B). Gently
curved incisions extending from proximal-lateral to distal-medial were often
used to account for the subsequent external rotation of the distal aspect of
the limb and to avoid hypertrophic scars resulting from excessive skin
tension. Furthermore, subperiosteal exposure of the humerus was performed with
care taken to protect the radial nerve posteriorly. Osteotomies were performed
just superior to the deltoid insertion. On completion of the transverse
osteotomy, the distal fragment was appropriately externally rotated to allow
for improved positioning of the hand away from the body and overhead. Prior to
the application of internal fixation, intraoperative assessment of the degree
of derotation was performed. In all patients, care was taken to ascertain that
the ipsilateral hand could be easily placed to the mouth, occiput, perineum,
and midline in an effort to avoid overcorrection. Osteotomies were stabilized
with stacked one-third tubular or 3.5-mm plates (Synthes, Paoli,
Pennsylvania), obtaining four to six cortices of fixation proximal and distal
to the osteotomy site. Postoperatively, patients were managed with
immobilization of the upper extremity in either a spica cast or a sling and
swath, depending on the age of the patient. Immobilization was typically
discontinued after four to six weeks, following radiographic confirmation of
osseous healing. Patients subsequently underwent physical therapy for
range-of-motion and strengthening exercises.
In patients with internal rotation and abduction contractures of the
shoulder with external rotation weakness, a combination of external rotation
and varus-producing osteotomies were performed to allow for an improved
position of the affected limb and to facilitate adduction of the upper
extremity against the body. In these situations, standardized preoperative
clinical and radiographic evaluations were performed as described above. In
general, these patients were younger, had less advanced glenohumeral
dysplasia, and had undergone prior tendon transfer and soft-tissue procedures
(e.g., capsulodesis, myodesis, or scapular stabilization) at an outside
hospital prior to their presentation to our institution. While improvements in
shoulder abduction and forward flexion were attained, this subset of patients
had development of persistent internal rotation and abduction contractures of
the shoulder with external rotation weakness. Compensatory scapulothoracic
motion was often used to adduct the arm toward the side of the body, resulting
in elevation of the superomedial border of the scapula, the so-called Putti
sign (Figs. 3-A through 3-D).
Because of the persistent limitations in both external rotation and shoulder
adduction in this group of patients, combined external rotation and
varus-producing osteotomies were performed to allow for improved positioning
of the affected limb and to facilitate adduction of the upper extremity
against the side of the body. The surgical approach to the humerus was
similarly by means of a deltopectoral approach. On completion of a transverse
osteotomy proximal to the deltoid insertion, the distal fragment was
externally rotated to induce the appropriate amount of rotational correction.
After derotation was completed, a varus-producing medial closing-wedge
osteotomy was performed, correcting for the shoulder abduction contracture.
Appropriate intraoperative correction was confirmed by noting the elimination
of the Putti sign with shoulder adduction. It is important that the
varus-producing osteotomy be performed after derotation to prevent
secondary deformity.
External rotation of the shoulder, expressed in degrees, was measured with
the arm adducted against the body and the elbow flexed 90°. These
measurements were made preoperatively, intraoperatively, and at the most
recent clinical evaluation. Comparisons of the means for continuous variables
were performed with the paired Student t test, utilizing Microsoft Excel 2000
software (Microsoft, Redmond, Washington). P values of <0.05 were deemed
significant.
The mean rotational correction achieved during derotational humeral
osteotomy was 64° (range, —40° to 90°). For the six patients
who underwent additional angular correction, a mean of 20° (range, 15°
to 25°) of varus alignment was introduced to the longitudinal axis of the
humerus. All patients went on to have successful healing at the osteotomy
site, and no patient had nonunion.
Overall, all patients demonstrated improvements in global shoulder function
following derotational humeral osteotomy, as evidenced by improved aggregate
Mallet classification scores. The mean aggregate Mallet classification score
improved from 13 points (range, 10 to 17 points) preoperatively to 18 points
(range, 13 to 23 points) postoperatively (p < 0.01). Several elements of
the modified Mallet classification demonstrated expected improvements
following humeral derotation. In particular, global shoulder external rotation
improved from 2 points (range, 1 to 4 points) preoperatively to 4 points
(range, 2 to 4 points) postoperatively (p < 0.01). Hand-to-mouth movement
improved from 3 points (range, 1 to 4 points) preoperatively to 4 points
(range, 3 to 5 points) postoperatively (p < 0.01). Similarly, hand-to-neck
motion improved from 3 points (range, 2 to 4 points) preoperatively to 4
points (range, 2 to 5 points) at the most recent follow-up (p < 0.01).
Radiographically, twenty-seven of the twenty-eight patients undergoing
derotational humeral osteotomy had type-III glenoid deformity or worse,
signifying posterior humeral head subluxation and increased glenoid
retroversion, and the mean glenohumeral morphology was type IV. One of the
twenty-eight patients had a type-II glenoid but was deemed a candidate for
derotational humeral osteotomy on the basis of the relatively atrophic and
insufficient soft tissue and musculature, precluding tendon transfers. Ten of
the twenty-seven patients had pseudoglenoid formation on magnetic resonance
imaging or computed tomography scans, and seven had posterior glenohumeral
dislocations. The mean postoperative deformity in the sixteen patients who had
follow-up imaging remained the same (type IV), with no evidence for remodeling
or improvement in glenohumeral deformity.
Six of the twenty-seven patients underwent a total of eight additional
surgical procedures following derotational humeral osteotomy. One patient
underwent revision of a hypertrophic scar. Another patient underwent a
revision derotational osteotomy for incomplete correction achieved by the
index procedure. Four patients required additional surgical treatment for
forearm and wrist involvement, including corrective forearm osteotomy (one
patient) and proximal row carpectomy with wrist arthrodesis (three patients).
One patient underwent subsequent latissimus dorsi and teres major tendon
transfers to the rotator cuff in the hope of improving active shoulder motion
despite substantial glenohumeral dysplasia, but there was no improvement in
abduction and only modest improvement in external rotation, according to the
modified Mallet classification system. One patient sustained a humeral
diaphyseal fracture below the previously placed plate during sports
participation, and it was successfully treated nonoperatively. No patient in
the study cohort underwent elective plate removal following derotational
humeral osteotomy.
Patients with brachial plexus birth palsy and persistent neurological
deficits have limitations of upper extremity function. Most commonly, upper
trunk lesions (C5-C6) result in weakness of the deltoid and rotator cuff
muscles, leading to limitations in shoulder abduction and external rotation.
Latissimus dorsi and teres major tendon transfers to the rotator cuff have
been shown to provide substantial improvements in shoulder function in these
situations14,15,17.
Previous investigations, however, have demonstrated that long-standing
muscular imbalance about the shoulder leads to progressive glenohumeral
dysplasia and/or
instability8-13.
Extra-articular soft-tissue rebalancing and tendon transfers alone may halt
the progression of glenohumeral deformity; however, these extra-articular
procedures alone do not lead to substantial glenohumeral joint
remodeling16.
Patients with long-standing brachial plexus birth palsy and moderate-to-severe
glenohumeral deformity—humeral head flattening, increased glenoid
retroversion, and/or posterior glenohumeral instability—may not be
candidates for soft-tissue procedures alone because of the limitations of
tendon transfers and soft-tissue releases in improving shoulder function in
the setting of an underlying incongruent glenohumeral articulation. Indeed,
some authorities believe that soft-tissue releases and tendon transfers
performed in the setting of glenoid dysplasia and humeral head flattening may
lead to iatrogenic anterior glenohumeral
instability18,27.
In these situations, improved function may be achieved by a derotational
humeral
osteotomy17-23.
Derotational humeral osteotomy does not improve overall glenohumeral motion
but, rather, improves upper extremity function by reorienting the arc of
shoulder rotation into a more functional range. By repositioning the hand into
a better position, derotational humeral osteotomy may allow for improved
shoulder and upper extremity function by means of glenohumeral as well as
scapulothoracic joint motion.
Kirkos and Papadopoulos reported the results for twenty-two patients with
brachial plexus birth palsy and rigid internal rotation contractures of the
shoulder who were treated with derotational humeral
osteotomy20. No
preoperative computed tomography or magnetic resonance imaging scans were
performed in these patients to quantify the degree of glenohumeral dysplasia
or posterior humeral head instability. In ten patients, the ends of the
humeral fragments were impacted following osteotomy and were stabilized with
"strong catgut sutures in the periosteum." The osteotomy was
stabilized with one staple in eight patients and with two staples in four
patients. All patients were managed with immobilization in a shoulder spica
cast for six weeks postoperatively. At an average duration of follow-up of
fourteen years (range, two to thirty-one years), the authors reported
increases in shoulder abduction and external rotation of 27° and 25°,
respectively. Forearm supination also improved, secondary to improved shoulder
external rotation. Four patients had an angular deformity develop
postoperatively at the osteotomy site, and it was attributed to the lack of
rigid internal fixation; these patients were treated by wedging the cast. In
twelve patients, the osteotomy site healed with 12° to 25° of valgus
deformity. On the basis of this experience, rigid internal fixation of the
osteotomy site with use of a plate-and-screw construct is now recommended.
Al-Qattan also reported the results of derotational humeral osteotomy in a
series of fifteen children with brachial plexus birth palsy and humeral head
deformity documented on preoperative magnetic resonance imaging
scans18. At an
average follow-up of three years, the patients demonstrated improvements in
shoulder function, with the mean modified Mallet score increasing from 2.2 to
4 points for hand-to-neck motion. No major complications were reported.
Al-Qattan further observed improvements in global shoulder abduction and elbow
flexion contracture, although these changes were not quantified.
The results of the current investigation confirm those of prior studies. In
this prospective evaluation of twenty-seven patients with brachial plexus
birth palsy and internal rotation contracture and/or advanced glenohumeral
deformity, derotational humeral osteotomy significantly improved global
shoulder function, as assessed by the modified Mallet classification system.
Furthermore, with use of reliable and standardized radiographic techniques,
the findings of the current study demonstrate that these improvements in
function occur despite persistent glenohumeral deformity or instability. As
anticipated, no improvement in joint morphology was seen in the patients with
postoperative axial imaging of the affected shoulder, nor was any progression
of deformity observed clinically.
It should be noted that six patients in this study cohort underwent
simultaneous derotational and varus-producing osteotomies. This subset of
patients warrants special mention. As noted, they were younger, had less
advanced preoperative glenohumeral deformity, and had undergone prior tendon
transfer and soft-tissue procedures. Despite improvements in shoulder
abduction and forward flexion, however, this subset of patients had persistent
internal rotation and abduction contractures of the shoulder with external
rotation weakness. As a result of the compensatory scapulothoracic motion, a
Putti sign was commonly seen. Because of the persistent limitations in both
external rotation and shoulder adduction, a combined external rotation and
varus-producing osteotomy was performed to allow for an improved position of
the affected limb and to facilitate adduction of the upper extremity against
the body. Appropriate intraoperative and postoperative correction was
confirmed by noting the elimination of the Putti sign with shoulder adduction.
As no additional soft-tissue procedures may adequately address this type of
deformity, varus-producing and/or derotational humeral osteotomy should be
considered in selected patients.
A number of questions merit future investigation. While it has been
established that derotational humeral osteotomy provides functional benefit to
patients with advanced glenohumeral deformity, it is assumed that earlier
surgical intervention with joint reduction, extra-articular soft-tissue
rebalancing, and tendon transfer procedures in younger patients may provide
better functional outcomes. Further analysis of patients who undergo both
tendon transfers and arthroscopic or open joint reduction procedures is
necessary to determine the utility of these intra-articular procedures in
altering the natural history of glenohumeral dysplasia and potentially
obviating the need for late osteotomy. In addition, the effect of concomitant
elbow flexion contractures on the results of derotational humeral osteotomy
was not considered in the current study. Future investigation is warranted to
determine the effect of ipsilateral elbow and/or forearm contractures on the
indications for and results of derotational humeral osteotomy in these
patients. Finally, longer-term outcomes studies must be performed to determine
the risk of pain and/or arthrosis, if any, in patients with brachial plexus
birth palsy and advanced glenohumeral dysplasia. A multicenter prospective
study is currently underway to address these important issues.
In conclusion, our results demonstrate that a derotational humeral
osteotomy significantly improves shoulder function in patients with brachial
plexus birth palsy, internal rotation contracture, and/or advanced
glenohumeral joint deformity. It provides an attractive treatment option for
these patients when advanced glenohumeral dysplasia precludes soft-tissue
releases and tendon transfers. Furthermore, the combined derotational and
varus-producing humeral osteotomy should be considered in selected patients
with internal rotation and abduction contractures with external rotation
weakness.
Tables showing the clinical details of all study patients and a depiction
of the modified Mallet classification system are available with the electronic
versions of this article, on our web site at
(go to
the article citation and click on "Supplementary Material") and on
our quarterly CD-ROM (call our subscription department, at 781-449-9780, to
order the CD-ROM). ?
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