Shoulder heterotopic ossification after bilateral hemiarthroplasty: case report and review of the literature Jonathan Cheah, BS a , Phillip Nigro, MD b , Eric Smith, MD b , Elizabeth Matzkin, MD b, * a Tufts University School of Medicine, Boston, MA, USA b Department of Orthopaedics, Tufts Medical Center, Boston, MA, USA Proximal humeral fractures are the third most common fracture in the elderly population after hip and distal radial fractures. 17,19 In 1970, Neer described excellent to satis- factory results after primary hemiarthroplasty for the treatment of displaced humeral head fractures. 23 Subse- quent studies have shown hemiarthroplasty provides good to excellent pain relief in 73% to 97% of patients. 8,9,12,14,26 Functional outcomes have been variable, however, ranging from excellent to poor. 1,5,9,22,36 One of the complications associated with poor functional outcomes is heterotopic ossification (HO) that can limit range of motion. 25 HO, also known as ectopic ossification, is the formation of bone outside the normal skeletal system, including skin, subcutaneous tissues, skeletal muscles, and fibrous tissues adjacent to joints. After total joint arthroplasty, HO can form in periarticular soft tissue and present with symptoms of joint pain, erythema, effusion, and decreased range of motion. 10 HO has been widely observed in total hip arthroplasty, 32 but the incidence and relevance to functional outcomes are much more variable in shoulder arthro- plasty. 1,21 In addition to joint arthroplasty, HO can occur in joints secondarily to traumatic neurologic lesions, with severe limitation in joint motion developing in 10% of these patients. 10,20 The joints most affected are the hip, followed by the knee and elbow. After a thorough search of the literature using PubMed and Ovid Medline, we are not aware of any reports of bilateral shoulder HO after bilateral shoulder hemi- arthroplasty. The purpose of this case report is to document the unique complication of bilateral HO after bilateral shoulder hemiarthroplasty and discuss its impact on the patient’s range of motion in relation to the previous literature. Case report A 62-year-old left handedominant man presented to our institu- tion with bilateral comminuted proximal humeral fracture dislo- cations sustained after an unwitnessed fall. The patient’s history was notable for 2 posterior fossa epidermoids that required neurosurgical craniectomy for resection 12 and 2 years prior. Other medical comorbidities included atrial fibrillation, diabetes, hypertension, hyperlipidemia, hemicolectomy after colon cancer, benign prostatic hypertrophy, prior cerebrovascular accident (CVA), Grave disease, chronic obstructive pulmonary disease, and prior inferior myocardial infarction. The patient had been found down in his home by a visiting nurse assistant and was initially admitted to another hospital for medical management of rhabdomyolysis, atrial fibrillation, deep vein thrombus (DVT), and possible pulmonary embolism (PE). The length of time spent down before discovery by the visiting nurse assistant was unknown. During the hospitalization at the other facility, he underwent a head computed tomography (CT) scan that showed no acute head injury. The patient did not require intubation for mechanical respiration or neuromuscular blockade at any point during treatment at the other hospital. The patient was medically stabilized and transferred to our tertiary care center on hospital day 6 to undergo orthopedic procedures and manage his multiple medical comorbidities. Concerns about a seizure-related mechanism of injury prompted an electroencephalography (EEG), which found a left temporal The Tufts Medical Center Investigational Review Board approved this report. *Reprint requests: Elizabeth Matzkin, MD, Tufts Medical Center Department of Orthopaedics, Box 306, 800 Washington St, Boston, MA 02111, USA. E-mail address: [email protected](E. Matzkin). J Shoulder Elbow Surg (2011) 20, e7-e13 www.elsevier.com/locate/ymse 1058-2746/$ - see front matter Ó 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. doi:10.1016/j.jse.2011.02.006
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The Tufts Med
report.
*Reprint req
Department of O
02111, USA.
E-mail addre
J Shoulder Elbow Surg (2011) 20, e7-e13
1058-2746/$ - s
doi:10.1016/j.jse
www.elsevier.com/locate/ymse
Shoulder heterotopic ossification after bilateralhemiarthroplasty: case report and review of the literature
Jonathan Cheah, BSa, Phillip Nigro, MDb, Eric Smith, MDb, Elizabeth Matzkin, MDb,*
aTufts University School of Medicine, Boston, MA, USAbDepartment of Orthopaedics, Tufts Medical Center, Boston, MA, USA
Proximal humeral fractures are the third most commonfracture in the elderly population after hip and distal radialfractures.17,19 In 1970, Neer described excellent to satis-factory results after primary hemiarthroplasty for thetreatment of displaced humeral head fractures.23 Subse-quent studies have shown hemiarthroplasty provides goodto excellent pain relief in 73% to 97% of patients.8,9,12,14,26
Functional outcomes have been variable, however, rangingfrom excellent to poor.1,5,9,22,36 One of the complicationsassociated with poor functional outcomes is heterotopicossification (HO) that can limit range of motion.25
HO, also known as ectopic ossification, is the formationof bone outside the normal skeletal system, including skin,subcutaneous tissues, skeletal muscles, and fibrous tissuesadjacent to joints. After total joint arthroplasty, HO canform in periarticular soft tissue and present with symptomsof joint pain, erythema, effusion, and decreased range ofmotion.10 HO has been widely observed in total hiparthroplasty,32 but the incidence and relevance to functionaloutcomes are much more variable in shoulder arthro-plasty.1,21 In addition to joint arthroplasty, HO can occur injoints secondarily to traumatic neurologic lesions, withsevere limitation in joint motion developing in 10% of thesepatients.10,20 The joints most affected are the hip, followedby the knee and elbow.
After a thorough search of the literature using PubMedand Ovid Medline, we are not aware of any reports of
ical Center Investigational Review Board approved this
uests: Elizabeth Matzkin, MD, Tufts Medical Center
rthopaedics, Box 306, 800 Washington St, Boston, MA
ee front matter � 2011 Journal of Shoulder and Elbow Surgery
.2011.02.006
bilateral shoulder HO after bilateral shoulder hemi-arthroplasty. The purpose of this case report is to documentthe unique complication of bilateral HO after bilateralshoulder hemiarthroplasty and discuss its impact on thepatient’s range of motion in relation to the previousliterature.
Case report
A 62-year-old left handedominant man presented to our institu-tion with bilateral comminuted proximal humeral fracture dislo-cations sustained after an unwitnessed fall. The patient’s historywas notable for 2 posterior fossa epidermoids that requiredneurosurgical craniectomy for resection 12 and 2 years prior.Other medical comorbidities included atrial fibrillation, diabetes,hypertension, hyperlipidemia, hemicolectomy after colon cancer,benign prostatic hypertrophy, prior cerebrovascular accident(CVA), Grave disease, chronic obstructive pulmonary disease, andprior inferior myocardial infarction.
The patient had been found down in his home by a visitingnurse assistant and was initially admitted to another hospital formedical management of rhabdomyolysis, atrial fibrillation, deepvein thrombus (DVT), and possible pulmonary embolism (PE).The length of time spent down before discovery by the visitingnurse assistant was unknown. During the hospitalization at theother facility, he underwent a head computed tomography (CT)scan that showed no acute head injury. The patient did not requireintubation for mechanical respiration or neuromuscular blockadeat any point during treatment at the other hospital.
The patient was medically stabilized and transferred to ourtertiary care center on hospital day 6 to undergo orthopedicprocedures and manage his multiple medical comorbidities.Concerns about a seizure-related mechanism of injury promptedan electroencephalography (EEG), which found a left temporal
Figure 1 (A) Preoperative bilateral shoulder anteroposterior radiographs show bilateral comminuted displaced fractures of the humeralheads. (B) Preoperative bilateral shoulder axillary radiographs show posterior dislocation of bilateral comminuted displaced fractures of thehumeral heads.
e8 J. Cheah et al.
lobe abnormality. The medical team clinically monitored thepatient during the inpatient hospitalization and did not note anysubsequent seizure activity. Further workup with magnetic reso-nance imaging was deferred to an outpatient setting withneurology. The patient’s rhabdomyolysis had been treated withcrystalloid fluid resuscitation at the other hospital. Upon arrival toour medical center, his creatinine phosphokinase level was withinnormal reference ranges.
The patient’s atrial fibrillation was addressed and controlledwith metoprolol. A lower extremity Doppler ultrasound studyconfirmed the presence of a left lower extremity DVT, anda subsequent CT pulmonary angiogram ruled out the presence ofa PE. Throughout the patient’s hospital course, he was continuedon his home dose of daily chewable 81-mg aspirin for his historyof CVA. Enoxaparin therapy for the DVT was held until hospitalday 13, the day after his second shoulder surgery.
The patient’s social history included previous tobacco use. Hedenied any alcohol or drug abuse. His occupations before retire-ment were truck driving and working as a cashier. The patientlives alone with visiting nursing assistance to care for his medicalissues and previously could perform activities of daily living.
On physical examination, he had bilateral shoulder swellingwith tenderness to palpation. The patient’s range of motion testingwas limited by pain. Radiographs showed bilateral comminutedproximal humeral fracture dislocations (Fig. 1, A). Both shoulderswere dislocated posteriorly (Fig. 1, B).
On hospital day 8 after his initial admission, the patientunderwent left shoulder hemiarthroplasty, followed by rightshoulder hemiarthroplasty on hospital day 12. The 2 procedureswere performed by different orthopedic surgeons, but with similartechniques and instrumentation. The deltopectoral approach wasused for both shoulders. During surgical exposure, the deltoid andpectoral muscles were found to be healthy and viable.
Fracture hematoma was encountered and cleaned with irriga-tion. Both humeral heads were identified as being fractured withposterior displacement and angulation. The greater and lessertuberosities of both shoulders were fractured, but with intactattachments to the rotator cuff tendons. The rotator cuff muscleswere carefully retracted with the tuberosity fragments, and thebiceps tendon was tenotomized.
Once clear exposure was obtained, the humeral shaft wasreamed and the canal contents were extensively irrigated andsuctioned. The left shoulder was replaced by cementing a 12 mmGlobal FX stem (DePuy, Warsaw, IN, USA) with a 52- � 18 mmhumeral head into the humeral shaft. The tuberosities wererepaired by passing suture sets through drill holes. The rightshoulder underwent similar repair with a 12 mm DePuy Global FXstem and a 48- � 18 mm humeral head. Medium viscosity bonecement with gentamicin was used for both implants. A bone graftfrom the humeral head was used to fill defects in the tuberosities.
Postoperative radiographs showed correct placement of hemi-arthroplasty implants, with the tuberosities noted as being fixed
Figure 2 (A) Anteroposterior and (B) axillary radiographs show the shoulders after bilateral hemiarthroplasty.
Shoulder heterotopic ossification after bilateral hemiarthroplasty e9
slightly inferior. Radiographs did not show excessive bone graftwithin the glenohumeral joint. However, both shoulders weretested intraoperatively and had good range of motion and stability,including posterior translation of 50% of the glenoid width(Fig. 2). Before closing, copious irrigation was performed withnormal saline. Both wounds had adequate hemostasis and did notrequire drain placement.
Each procedure was performed under general anesthesia andthe patient was extubated without any complication or prolongeduse of neuromuscular blockades. Each shoulder procedure had anestimated blood loss of 400 mL. During the second shoulderprocedure, the patient received 1 unit of packed red blood cells(pRBCs) intraoperatively, and 1 more unit on postoperative day 1for a hematocrit of 30. On postoperative day 4, he was givenanother 2 units of pRBCs because his hematocrit had drifted downto 24. Thereafter the patient’s hematocrit remained stable at 30,and he showed no clinical signs of bleeding. After the lastshoulder procedure, the patient was placed on an enoxaparinbridge and started on warfarin for a lower extremity DVT.
Postoperatively, the patient began physical therapy usinga standard protocol. Phase I (0-4 weeks) consisted of elbow and
wrist range of motion exercises and gentle pendulums. Duringphase II (4-8 weeks), the patient was instructed on assistedforward elevation to 90�, external rotation to 40�, and internalrotation in the scapular plane. Phase III (8-12 weeks) consistedof active and passive range of motion exercises as tolerated,weight bearing as tolerated, and initiation of isometricstrengthening.
At 3.5 months, the patient experienced significant pain whenundergoing physical therapy to gain range of motion in hisshoulders. Physical examination of both shoulders demonstratedactive forward flexion limited to 85� and abduction to 70�.Radiographs showed bilateral grade IV HO that bridged across theglenohumeral joints and had progressed in severity by the 6-monthpostoperative visit in both externally and internally rotated ante-roposterior views (Fig. 3). Axillary views could not be obtaineddue to the patient experiencing pain secondary to the restrictedrange of motion. Increased lucency around the lateral stem of eachprosthetic implant was noted. However, given the patient’scontinued pain relief and progressive glenohumeral ossification,these lucencies were unlikely to have contributed to this patient’spostoperative complaints of restricted motion.
Figure 3 Extensive heterotopic ossification around the glenohumeral joints is seen in at 6 months after bilateral shoulder hemi-arthroplasty in (A) externally rotated anteroposterior radiographs and (B) internally rotated anteroposterior radiographs.
e10 J. Cheah et al.
By the 6-month postoperative visit, the patient’s range ofmotion had become progressively more limited, with the rightshoulder having active forward flexion to 60� and abduction to65�. The left shoulder was further limited to 60� of forward flexionand 45� of abduction. With the arm at the side, external rotationwas 0� and internal rotation was 60� bilaterally. Currently, thepatient is satisfied with pain relief in his shoulders and canperform activities such as dressing and feeding himself, but heneeds assistance for activities that require overhead motion.
The patient has expressed interest in resection of the HO in hisleft dominant shoulder. This treatment will be considered at the1-year postoperative interval to allow maturation of HO. Thepatient’s course will be monitored for changes in his range ofmotion and with follow-up shoulder radiographs to detect theprogression of HO. If the patient undergoes resection of the HO inhis dominant shoulder, he will be treated with postoperativenonsteroidal antiinflammatory drugs (NSAIDs) or radiotherapy(RT) to prevent reoccurrence.
Shoulder heterotopic ossification after bilateral hemiarthroplasty e11
Discussion
In 1970, Neer described a classification system for HOcomplications in 14 of his 117 patients (12%).23 Thisclassification system was later modified by Brooker and isused to describe degrees of HO formation:
grade Idislands of bone within the soft tissue,grade IIdgreater than 1-cm gap between opposing bonesurfaces,grade IIIdless than 1-cm gap between opposing bonesurfaces, andgrade IVdankylosis.6
In Brooker’s classification system, grade III/IV ossifi-cation was associated with a clinically significant decreasein shoulder range of motion.18 Subsequent studies ofhumeral head replacements have shown variable rates ofHO, but most agree that very few patients progress to gradeIII/IV and subsequent limited range of motion.
In 1983, Tanner and Cofield31 noted that HO had devel-oped in 6 patients (12%) after humeral hemiarthroplasty;however, these cases had minimal clinical consequence. TheHO was graded as mild and occupied less than one-third ofthe glenohumeral and subacromial interval.
Kjaersagaar-Anderson et al18 found HO in 26 patients(45%) 1 year after total shoulder arthroplasty. Nonetheless,only 6 patients (10%) demonstrated a grade III/IV ossifi-cation with associated restriction of forward elevation.They also noted that the severity of pain did not correlate tothe amount of HO.
Sperling et al29 reported an HO incidence of 24% in 58of patients who underwent total shoulder arthroplasty. Ofthese patients, only 2 were identified to have HO occu-pying >50% of the glenohumeral joint. No patientsprogressed to form high-grade HO that bridged the gle-nohumeral joint.
In 2003, Mighell et al21 described HO in 18 shoulders(25%) after hemiarthroplasty, but only 1 patient hadsignificant loss of range of motion, with grade IV HO.
A 2004 study by Boehm et al4 reported HO in 11 of 126patients (15%) after hemi or total shoulder arthroplasty.Only 6 of these patients presented with HO that occupied>50% of the glenohumeral joint, and none had severebridging HO.
In 2007, Gr€onhagen et al13 described HO developmentin 25 patients (54%) after hemiarthroplasty.13 Yet, thesepatients were found to have low-grade HO, without any lossof range of motion.
Together these studies suggest that HO formation hasa variable incidence of 15% to 54% after shoulder arthro-plasty. In addition, these studies have shown that very fewof these patients will progress to grade III/IV HO withsignificant loss of range of motion.
Although grade III/IV HO after hemiarthroplasty isuncommon, it can potentially restrict range of motion and
contribute to poor functional outcomes. This case demon-strates the unique formation of high-grade bilateral HO. Toour knowledge, there has been no case report of bilateralformation of shoulder HO after bilateral hemiarthroplasty,much less grade IV with significant limitation in range ofmotion. The patient’s range of motion is thought to consistof mostly scapulothoracic motion due to the high degree ofHO bridging across the glenohumeral joint. Similar limi-tations in range of motion are seen in patients who haveundergone glenohumeral arthrodesis.27
Certain factors must be considered to evaluate the riskof HO formation when patients undergo humeral headreplacement, such as ankylosing spondylosis, diffuseidiopathic skeletal hyperostosis, high energy injuries,history of HO, delay in treatment beyond 10 to 14 days,and whether the procedure is a revision for a failed internalfixation.7,16
The unusual posterior dislocation of our patient’s injurysuggests a possible seizure and a subsequent fall. However,because the fall was unwitnessed, a higher energy injurycannot be ruled out. It is possible that the patient’s rhab-domyolysis could have been from a severe shoulder girdlemuscle injury that may have contributed to the severity ofHO formation. This is less likely, however, because therhabdomyolysis had resolved upon transfer to our medicalcenter, and the intraoperative examination showed intactand viable shoulder girdle musculature. The relationshipbetween rhabdomyolysis and HO has not been clearlydefined, as suggested by Beuthoux et al.2
Although the patient’s time from injury to the initialhospitalization is unknown, the right shoulder may be athigher risk because fixation was delayed until hospital day12, compared with the left shoulder that underwent fixationon hospital day 8. Interestingly, the right glenohumeraljoint showed more abundant HO formation.
The unusual severity of our patient’s HO may suggestother potential contributors, because he does not havetypical risk factors, such as a history of ankylosing spon-dylosis, diffuse idiopathic skeletal hyperostosis, or previousHO. The possibility of bleeding may have contributed tothe severity of HO formation because the patient did lose400 mL per shoulder procedure and he received 4 units ofpRBC during his hospitalization. However, the patient hadstable hematocrit at discharge, with no clinical signs ofactive bleeding.
The patient’s history of neurosurgical procedures is alsosuspected to have contributed to a predisposition to HOformation as a form of iatrogenic head injury. HO has beenreported to occur in 10% to 20% of patients with closed-head injuries, and is most common in the hip. Severelimitations in range of motion develop in 10% of thesepatients.20 With regards to the shoulder, however, there area limited number of studies about HO and neurologicinjury.11,15,33,34 These studies deal with shoulder HOformation only after blunt or penetrating head trauma.
e12 J. Cheah et al.
We are not aware of any studies that illustrate the rela-tionship between distant neurosurgical procedures as a formof iatrogenic head trauma and a subsequent predisposition toHO. Further investigation is important to determine ifa history of head injury or neurosurgical intervention mayplace patients at increased risk for formation of HO whenundergoing shoulder arthroplasty. If such a risk factor were toexist, it might be prudent to place such patients on a post-operative HO prophylaxis regimen with NSAIDs or RT.Although our patient was not prescribed a specific HOprophylaxis, it is notable that he was administered 81 mg ofaspirin for his history of CVA and a significant amount of HOstill developed.
To address our patient’s HO, an excision will beconsidered after the 1-year interval from surgery and oncethe HO formation has matured with clearly defined marginson radiographs. Recent literature has shown NSAID and RTare both efficacious in the prevention of HO.3,4,24,28,30,35
Although there are conflicting claims about whichtherapy is superior, there is literature to suggest that RT ismarginally more effective than NSAIDs in the preventionof severe grade III/IV HO.3,24,28
Board et al24 reviewed a number of randomized controltrials comparing NSAIDs with RT and noted marginallyless grade III/IV HO with RT. A meta-analysis comparingRT with NSAIDs favored RT, with a risk ratio of 0.42(95% confidence interval, 0.18-0.97) in prevention ofBrooker grade III/IV HO.24 Although RT might be indi-cated for our patient’s HO, a discussion with the patientabout the benefits and risks of both modes of pro-phylaxis will be also be used to choose the most accept-able treatment.
Conclusions
In conclusion, although HO of the hip has been wellcharacterized in previous works, HO formation in theshoulder still has many features that require future study.Specifically, there is little information regarding the riskfactors for HO formation after shoulder arthroplasty.Although this procedure has inherent risks of HOformation, these formations are usually of mild clinicalsignificance. However, our case report of bilateral HOformation after hemiarthroplasty documents significantHO formation that greatly impeded the patient’s range ofmotion. The severity of this patient’s presentation raisesconcerns for other potential contributing factors.Previous studies have indicated that closed head traumahas been associated with HO formation of the hip. Theclinical course of this patient brings into questionwhether a previous neurosurgical intervention can beconsidered a form of iatrogenic head trauma thatcontributes to an increased risk of HO. Further study of
potential risk factors could prove useful in the process ofselecting surgical candidates and management of HOcomplications after shoulder arthroplasty.
Disclaimer
The authors, their immediate families, and any researchfoundations with which they are affiliated have notreceived any financial payments or other benefits fromany commercial entity related to the subject of this article.
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