Radioulnar Heterotopic Ossification
After Distal Biceps Tendon Repair:
Results Following Surgical Resection
Robert W. Wysocki, MD, Mark S. Cohen, MD
From the Rush University Medical Center, Department of Orthopaedic Surgery, Chicago, IL.
Purpose: The purpose of this study is to evaluate the clinical outcome of patients who had
excision of a radioulnar heterotopic ossification (HO) as a complication of a distal biceps
tendon repair. The hypothesis is that there are no measurable clinical losses that persist after
Methods: Eight consecutive patients were identified between 1996 and 2005. All were
treated with HO excision using a standard surgical technique and rehabilitation protocol.
These individuals were studied and compared to a matched cohort of 8 patients who had a
distal biceps tendon repair with a similar surgical technique that was uncomplicated. All
study patients were evaluated at a minimum 1-year follow-up with physical examination,
isokinetic dynamometry, and outcome measures. Comparisons were made both between
groups as well as side-to-side within groups.
Results: At follow-up examination, the mean arc of forearm rotation in the HO group
measured 151°. The mean arc of forearm rotation in the control group measured 165°. With
the numbers available, no measurable differences in arc of motion were identified between
groups (p ? .05). When compared to the normal, uninvolved side, patients who developed
HO lost an average of 9° of forearm pronation (p ? .01). No differences were identified
between the HO and control groups with respect to isokinetic torque, endurance strength, or
Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire (American Academy of
Orthopaedic Surgeons, Rosemont, IL) scores (p ? .05).
Conclusions: When patients develop motion-limiting HO after distal biceps tendon repair,
surgical resection can lead to a functional recovery of elbow and forearm motion. Biceps
strength can be maintained with no measurable differences in clinical outcome when
compared to individuals who do not suffer this complication following distal biceps repair.
(J Hand Surg 2007;32A:1230–1236. Copyright © 2007 by the American Society for Surgery
of the Hand.)
Type of study/level of evidence: Therapeutic III.
Key words: Distal biceps, heterotopic ossification, isokinetic dynamometry, radioulnar syn-
ostosis, 2-incision technique.
cidence of 1.2 per 100,000 persons per year.1,2Direct
repair of the biceps tendon to the radial tuberosity has
been demonstrated to improve strength and func-
tion.3,4The procedure is not without potential com-
plications, however, with one of the most devastating
being the development of motion-limiting hetero-
topic ossification (HO) between the radius and the
ulna. This complication was initially attributed to the
raumatic rupture of the distal biceps tendon is
a rare injury, comprising approximately 3% of
all ruptures of the biceps with an overall in-
surgical approach in a 2-incision technique in which
both the radius and ulna were exposed.5,6The devel-
opment of radioulnar HO and synostosis, however,
has also been reported in muscle-splitting 2-incision
exposures of the tuberosity and much less frequently
when a single anterior exposure is used for re-
Once motion-limiting heterotopic bone forms, sur-
gical resection can improve clinical outcome.16,19–22
This procedure, however, carries the risk of neuro-
vascular injury and can lead to disruption of the
The Journal of Hand Surgery
original distal biceps tendon repair.23This study re-
ports on a group of patients treated with surgical
resection of motion-limiting HO that occurred fol-
lowing distal biceps tendon repair. A lateral surgical
approach was used without exposure of the radial
nerve. Outcome is assessed using standardized tools
including isokinetic dynamometry. In addition, we
asked whether the development of this complication
compromises ultimate upper extremity strength and
function, compared to patients who had an uncom-
plicated distal biceps tendon repair. Our hypothesis is
that, after excision, there are no measurable clinical
losses in patients who develop motion-limiting HO
after distal biceps tendon repair. Information on ul-
timate strength and function in this patient population
is not currently available in the literature.
Materials and Methods
Eight patients who developed motion-limiting HO
between the proximal radius and ulna as a compli-
cation of a distal biceps repair were referred for
evaluation and treatment by the senior author be-
tween 1996 and 2005. All patients had their original
repair performed using a 2-incision technique. Six
had the tendon inserted into a bony trough using
transosseous sutures. Two patients had the repair
performed with the use of bone anchors. Two oper-
ative reports described a muscle-splitting lateral ap-
proach to the tuberosity.5,12The 6 remaining opera-
tive reports lack detail regarding the initial lateral
exposure. Patients ranged in age from 31–48 years,
with a mean age of 40 years. All were men. The
mean time between the original injury and primary
repair was 14 days. No patients were initially treated
with any prophylaxis for HO.
At presentation, the average preoperative arc of
elbow motion was 127° (range, 115° to 135°). Pre-
operative forearm rotation was absent in 2 individu-
als with a complete radioulnar synostosis, and aver-
aged a total of 25° in the other 6 patients with
motion-limiting radioulnar HO. Seven of the 8 pa-
tients were laborers who sustained the injury at work,
and 1 patient injured the arm at home. Five of the 8
patients sustained the injury to the dominant arm.
All patients had radiographic evaluation of the
elbow and proximal forearm using plain radiographs
including oblique views. Advanced imaging was not
used. All patients were noted to have developed
heterotopic bone between the radius and the ulna at
the level of the radial tuberosity (Figs. 1A and 1B).
There was no ectopic bone involving the radiocapi-
tellar or ulnohumeral articulations. Surgical resection
was performed when the heterotopic bone appeared
mature, as defined by sharp cortical margins on plain
radiographs.24,25The average time from the initial
surgery to surgical resection was 6 months (range, 4
to 9 months).
All patients had a resection of the HO using a
standardized approach. After administration of a
long-acting regional block, the previous lateral inci-
sions were extended proximally and distally, and the
anconeus-extensor carpi ulnaris interval was defined.
Blunt dissection was carried down to expose the
supinator and the lateral border of the ulna. Care was
taken to keep the dissection distal to the radial head
and thus distal to the lateral ulnar collateral ligament
insertion. Dissection was then performed from pos-
terior to anterior, elevating the insertion of the supi-
nator off the ulna to expose the HO. Subperiosteal
elevation was continued until the radial shaft was
exposed. Care was taken to define a normal in-
terosseous space proximal and distal to the hetero-
topic bridge. Intraoperative fluoroscopy was used in
The bony bar was resected with a variety of instru-
ments including rongeurs, osteotomes, and a low-speed
burr. In an effort to maintain the integrity of the previ-
ously repaired tendon, the resection was performed in
supination as much as possible, and care was taken to
develop a concavity in the ulna opposite the tuberosity
to allow for full pronation (Fig. 1C). In no cases did the
biceps tendon insertion require release. All motion-
limiting bone was resected from this approach until full
rotation was restored on the table (Figs. 1D and 1E).
The posterior interosseous nerve was not exposed in
any case. Once full passive motion was achieved, the
fascia and soft tissues were closed in the usual manner
over a drain.
After surgery, all patients were placed into immedi-
ate, continued passive motion, taking the forearm
through rotation. Formal therapy was begun on the
morning following surgery and included edema control
modalities, active and passive range of motion exer-
cises, and patient-adjusted static bracing of the forearm.
of external beam radiation (700 cGy) provided on post-
operative day one. In addition, all patients were treated
with oral Indomethacin (Merck & Co., Inc., White-
house Station, NJ) for a total of 3 weeks.
In an effort to compare the outcome of these
patients with those who had an uncomplicated pri-
mary distal biceps repair, a control group of 8 men
was identified from the records of the senior author.
Every distal biceps repair performed during the study
Wysocki and Cohen / Radioulnar HO After Biceps Repair
The Journal of Hand Surgery / Vol. 32A No. 8 October 2007
period was reviewed, and these individuals were
matched with the HO group for age, follow-up inter-
val, dominance, etc. Their average age was 44 years
(range, 36–52 years). All control patients were
treated for acute distal biceps repairs with a 2-inci-
sion technique. Four of the 8 control patients injured
the dominant arm.
All patients from both the study and control groups
had follow-up examinations specifically for the pur-
poses of this study. Institutional review board ap-
proval and informed consent was obtained. Patients
were evaluated by an independent examiner in all
cases. Each patient completed a 30-item Disabilities
of the Arm, Shoulder and Hand (DASH) outcomes
questionnaire (American Academy of Orthopaedic
Surgeons, Rosemont, IL), which was scored by the
formula 25 ? [(sum of n responses/n) ? 1]. All
patients had elbow and forearm range of motion
measurements obtained of both the affected and un-
affected extremities using a standard goniometer.
Forearm rotation was measured with the arm at the
patient’s side and the elbow flexed to 90° while
gripping a pen in each hand.
All patients had isokinetic strength in elbow flex-
ion and forearm supination evaluated at the final
follow-up examination, using the CYBEX Extremity
System 340 Isokinetic Dynamometer (CYBEX Inter-
national, Inc. Medway, MA). Patients were in-
structed not to participate in any workouts or activ-
ities that would stress the biceps for 48 hours prior to
the evaluation. Before the strength testing, each pa-
tient was allowed 3 minutes of low-intensity warm-up
on a hand bicycle. Patients were positioned supine for
elbow flexion and sitting upright for forearm rotation.
The machine’s axis of rotation was aligned with that
of the elbow joint and the forearm, respectively.
Because there was no clear consensus regarding the
ideal testing parameters for this population, a proto-
col was chosen based on those most commonly used
in the literature.1,3,4,7,13,14,26–29Five low-intensity
repetitions to become familiar with the angular ve-
locity were allowed prior to each velocity and posi-
tion change. Patients were instructed to use maximal
exertion and speed on each and every repetition of
testing. The protocols for both elbow flexion and
forearm supination were identical and consisted of 1
set of 3 repetitions at an angular velocity of 90° per
second, from which the value for the single highest
peak torque was recorded, and a second set of 15
repetitions at an angular velocity of 240° per second,
from which a fatigue index was calculated to esti-
mate endurance. The fatigue index is defined as the
percentage of decline in work done during the last
20% (3 repetitions in this protocol) compared to the
first 20% of the set. The result is calculated by the
formula 100 ? [1?(work over last 20% / work over
first 20%)]. Positive values reflect a decrease in
work done over time, whereas negative values
reflect an increase in work. The peak torque set for
each exercise was always performed prior to the
fatigue set. Subjects were given 45 seconds rest
after each set.
Comparisons between the control and HO groups
were performed using the Mann-Whitney U test.
Side-to-side comparisons within each group were
performed using the Wilcoxon signed-rank test. In-
clusion of 8 HO and 8 control patients ensured 80%
power for detecting a difference between the HO and
control populations, if the probability that a measure-
ment from 1 population is less than a measurement
from the other population is 0.904, based on a
2-sided Mann-Whitney test with a 0.05 significance
The 8 members of the HO group were evaluated at a
mean follow-up interval of 57 months (range, 12–
120 months). No HO patients were lost to follow-up
examination. The control group of 8 patients was
evaluated at a mean follow-up interval of 56 months
(range, 12–129 months). Although the study was
limited by the small sample sizes, there were no
differences in age or length of follow-up interval
between the HO and control groups (p ? .05).
Heterotopic Ossification Group
There were no intraoperative or postoperative com-
plications following HO excision, and no patients
Figure 1. (A) Oblique and (B) lateral radiographs demonstrating mature heterotopic bone between the proximal radius and ulna
that developed as a complication following a distal biceps tendon repair. This typically forms at the level of the bicipital
tuberosity. (C) Intraoperative photograph following resection of the heterotopic bone. Note exposure of the ulna and the radius
with reconstitution of the interosseous space. Full forearm rotation is documented on the table prior to closure. (D) Oblique and
(E) lateral radiographs obtained after surgery. Note the absence of heterotopic bone and the slight concavity in the ulna opposite
the radial tuberosity to allow for full forearm pronation without compromise of the biceps tendon insertion.
Wysocki and Cohen / Radioulnar HO After Biceps Repair
required further surgery on their upper extremity. All
8 patients returned to work without restrictions at an
average of 10 weeks (range, 3–23 weeks) following
their release surgery.
At follow-up examination, mean elbow motion in
flexion and extension measured 3° to 135° in the
affected elbow versus 4° to 136° on the contralateral
side (p ? .05). Mean supination at final follow-up
examination measured 86° (range, 64° to 105°) and
mean pronation measured 65° (range, 50° to 78°).
These were both improved from measurements ob-
tained prior to HO resection (p ? .01). Although the
study was limited by the small sample size, when
compared to the normal arm, only forearm pronation
was measurably decreased, averaging 74° (range, 64°
to 82°) on the unaffected side (p ? .01).
Mean peak torque in flexion on the affected side
averaged 61 Nm. Mean peak flexion torque on the
control side averaged 57 Nm. These differences were
not significant (p ? .05). Mean peak supination
torque measured 11 Nm on the affected side and 9
Nm on the control side. These differences were also
not significant (p ? .05). The mean fatigue index for
flexion in the affected and unaffected arms revealed
decreases in strength of 20% and 17%, respectively,
over time (p ? .05). Strength by supination fatigue
index decreased 10% over time in the affected arm
versus a 13% decrease in the unaffected arm. This
difference was not significant (p ? .05). The mean
DASH score in the HO group at the final follow-up
examination measured 11 (range, 0–26). The afore-
mentioned comparisons are limited by the small sam-
At the follow-up examination, mean elbow motion in
flexion and extension measured 0° to 131° in the
affected elbow versus 1° to 134° on the contralateral
side (p ? .05). Mean supination at the final follow-up
examination averaged 89° (range, 83° to 95°) and
mean pronation measured 75° (range, 65° to 86°). No
differences in motion were observed when the af-
fected arm was compared to the contralateral control
limb (p ? .05).
Mean peak torques in flexion and supination mea-
sured 53 Nm and 9 Nm, respectively, in the affected
arm. These values measured 53 Nm and 11 Nm in the
contralateral arm, respectively. No side-to-side dif-
ferences in mean torque were identified (p ? .05).
The mean fatigue index for flexion demonstrated
decreases in strength of 21% in the affected arm and
18% in the unaffected arm over time (p ? .05).
Supination fatigue strength decreased over time by
25% in the affected side and by 16% on the control
side. This difference was not significant (p ? .05).
The mean DASH score in the control group at the
final follow-up examination measured 4 (range,
Comparison Between Groups
When the affected limbs of the HO group were
compared to the control group’s affected limbs, there
were no significant differences identified in range of
motion at final follow-up examination (p ? .05)
(Table 1). When isokinetic strength testing was com-
pared between groups, no differences were identified
in peak torques or fatigue indices (p ? .05). The
mean DASH score demonstrated a trend toward
worse outcome in the HO group, but this difference
was not significant (p ? .09). At the follow-up ex-
amination, all patients in both groups were able to
return to their previous occupations.
Motion-limiting HO is a rare but well-documented
complication following distal biceps repair, with a
reported incidence of 1% to 8%.1,3,4,7–16,30,31It oc-
curs most commonly with 2-incision techniques. To
our knowledge, there have only been 2 series de-
scribing outcomes after takedown of HO resulting
from a distal biceps repair. Failla et al12presented 4
cases of HO that occurred after 2-incision biceps
repairs. All were treated with excision of the HO, 2
with placement of an interposition silicone sheet.
Table 1. Clinical Results
86 ? 12
89 ? 4
65 ? 12*
75 ? 8
8 ? 16
1 ? 13
5 ? 31
7 ? 37
20 ? 8
21 ? 13
10 ? 26
25 ? 27
11 ? 9
4 ? 6
*Pronation was significantly less than that of the unaffected arm (p ? 0.01).
**Calculated by the formula [(Affected / Unaffected) ? 100] ? 100, with peak torque measured in Nm.
***Calculated by the formula 100 ? [1?(work over last 20% / work over first 20%)].
The Journal of Hand Surgery / Vol. 32A No. 8 October 2007
Two of the 4 cases of HO recurred. Of the 2 patients
with good outcomes, only 1 was able to achieve an
acceptable, functional arc of forearm rotation. There
was no description of objective strength measure-
ment or functional assessment in this series.
Sotereanos et al16more recently published a report
of 8 patients who had resection of HO that developed
following distal biceps tendon repair. All patients
received 700 cGy of local irradiation and aggressive
physical therapy beginning 24 hours after surgery.
Their operative technique was similar to ours except
that they visualized and performed a neurolysis of the
posterior interosseous nerve through a separate mus-
cular interval, whereas in our study the nerve was not
identified. At an average of 27 months after surgery,
they reported a mean total arc of forearm rotation of
155°. The authors mention that supination strength in
the affected extremity was 80% of that of the con-
tralateral limb, but there is no data provided as to
how this was measured.
We report on 8 patients who had HO resection
through a more limited lateral approach. By elevating
the supinator off the ulna, the posterior interosseous
nerve was protected and not separately exposed. No
nerve deficits occurred using this approach. At an
average follow-up interval of 57 months, all patients
recovered near full forearm rotation with an average
151° arc. This is comparable to that obtained by
Sotereanos et al. We did, however, identify a loss of
9oof final pronation, when compared to the normal,
uninvolved side (p ? .01). The functional signifi-
cance of this pronation loss is not clear. Isokinetic
strength testing showed no side-to-side differences in
flexion or supination torque or fatigue at the fol-
When compared to a cohort of patients who had
uncomplicated distal biceps tendon repairs, there was
a trend toward worse functional outcomes when mea-
sured by DASH scores. The 2 patients in the HO
group with DASH scores over 20 (mean of 11 for the
group) had an average of 53° pronation (mean of 65°
for the group). It is feasible that the limited pronation
in these patients was a main contributor to their
poorer functional outcome on the DASH index. Iso-
kinetic testing of the involved side, however, re-
vealed no measurable differences in strength or en-
durance between patients who had an uncomplicated
biceps repair and those who developed motion-lim-
iting heterotopic bone requiring surgical excision. As
quantified in the results, it is notable that the affected
arm in both groups was able to achieve supination
strength nearly identical in magnitude to that of the
unaffected contralateral side.
The primary weakness of this study relates to the
relatively small sample size, which is attributable to
the rarity of the complication. It is possible that
further differences might have been detected with a
greater number of patients, decreasing the chance of
Type II error. Nonetheless, our results suggest that
patients who undergo resection of motion-limiting
HO as a complication of a distal biceps repair can
reliably regain a functional range of motion, retain
their biceps strength, and return to their original level
of work. Although they require a second operation
and prolonged rehabilitation, their ultimate strength
and function do not appear to be compromised by
Received for publication May 23, 2007; accepted in revised form June
No benefits in any form have been received or will be received from
a commercial party related directly or indirectly to the subject of this
Corresponding author: Robert W. Wysocki, MD, 1150 West Lill, Apt.
3, Chicago, IL 60614; e-mail: Robert_Wysocki@rsh.net.
Copyright © 2007 by the American Society for Surgery of the Hand
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