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Surgical treatment of displaced proximal humerus fractures with a short intramedullary nail
J Shoulder Elbow Surg (2011) 20, 1241-1247
www.elsevier.com/locate/ymse
Surgical treatment of displaced proximal humerus fractures with a short intramedullary nail Betsy M. Nolan, MDa, Matthew A. Kippe, MDb, J. Michael Wiater, MDc,*, Gregory P. Nowinski, MDc a
Indiana University School of Medicine, Indianapolis, IN, USA Sports Medicine and Shoulder Surgery, Hawthorn Medical Associates, North Dartmouth, MA, USA c Department of Orthopaedic Surgery, William Beaumont Hospital, Royal Oak, MI, USA b
Background: The Polaris nail is an intramedullary device for treating displaced proximal humerus fractures with few published studies to support its use. Results of a consecutive series of patients treated with the Polaris nail are presented. Methods: Eighteen patients with a mean age of 71 years (range, 37-84) were treated for twelve 2- and six 3-part fractures. Radiographic results for all patients were evaluated. Thirteen patients with an average follow-up of 42 months (range, 24-84) were available for functional evaluation. Results: Seventeen of 18 patients healed. Postoperatively, the neck/shaft angle collapsed an average 11 (range, 5-30 ) into varus. Nine of 18 patients had final neck/shaft angles <120 and were considered radiographic malunions. The mean Constant and American Shoulder and Elbow Surgeons (ASES) scores were 61 (range, 20-100) and 67 (range, 10-100), respectively. Forward elevation averaged 118 . Patients had an average 5/8 positive rotator cuff signs. Seven patients underwent reoperation for loss of fixation or prominent hardware, and 1 required revision to a hemiarthroplasty. Conclusion: This study shows a higher than reported percentage of unsatisfactory results using the Polaris nail. The device violates the rotator cuff and is unable to resist the deforming forces that can lead to loss of fixation and varus collapse. Level of evidence: Level IV, Case Series, Treatment Study. Ó 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. Keywords: Proximal humerus fracture; intramedullary nail; malunion; rotator cuff; shoulder; fracture Polaris nail
Proximal humerus fractures are common injuries. Most proximal humerus fractures are minimally displaced and can be treated successfully without surgery.3,13,16,20 Less This study was approved by the Human Investigation Committee: # 2003228. *Reprint requests: J. Michael Wiater, MD, Chief of Shoulder Surgery, Department of Orthopaedic Surgery, William Beaumont Hospital, 3601 West Thirteen Mile Road, Royal Oak, MI 48073, USA. E-mail address: [email protected] (J.M. Wiater).
commonly, displaced or unstable fractures may require surgical management. With an aging population and associated increased prevalence of osteoporosis, the incidence of proximal humerus fractures will increase as will the number that require operative fixation. A variety of treatment options for surgical treatment of proximal humerus fractures are currently available, including nonlocking plate and screws, locking plate and screws, intramedullary nails, Enders rods, percutaneous pinning, blade plate and screws, heavy suture
1058-2746/$ - see front matter Ó 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. doi:10.1016/j.jse.2010.12.010
1242 fixation, tension band wiring, and prosthetic arthroplasty. Moreover, no consensus exists over which technique is the best for managing these challenging fractures. The Polaris nail (Acumed, Beaverton, OR) is an 11.0 x 150-mm titanium nonreamed antegrade intramedullary device designed for stabilization of proximal humerus fractures. Previous studies have reported good clinical and radiographic outcomes for both young and elderly patients with the use of this device.2,10,16 We present a consecutive series of patients with proximal humerus fractures treated with the Polaris nail. The purpose of this study was to evaluate both radiographic and functional results of the Polaris nail and to compare those results with previously published data. We hypothesize that Polaris nail fixation of 2- and 3-part proximal humerus fractures results in high rates of both varus malunion and unsatisfactory clinical outcome.
Materials and methods Eighteen patients with unilateral displaced proximal humerus fractures were treated with reduction and stabilization using a short, nonreamed antegrade interlocking intramedullary nail by the senior authors (GPN and JMW) between 1997 and 2002. The mechanism of injury was a low-energy fall in 16 and a high-energy motor vehicle accident in 2. Exclusion criteria included minimally displaced fractures, displaced 4-part fractures, unacceptable medical risks for surgery, and refusal of operative treatment. Radiographic and clinical results were retrospectively reviewed. General anesthesia, interscalene regional anesthesia, or a combination of both was performed. The beach chair position was utilized, with the operative extremity draped free. A superior skin incision was placed approximately 1 cm lateral to the anterolateral border of the acromion. The lateral deltoid muscle was split in line with its fibers. Traction sutures were placed around the tuberosity fragments according to the fracture pattern. Under fluoroscopic guidance, the entry point for the nail was localized with a 2.0-mm guide wire. This was typically through the supraspinatus tendon posterior to the long head of the biceps tendon, and just onto the humeral articular surface medial to the greater tuberosity. The supraspinatus tendon was then incised longitudinally and the tendon edges tagged with traction sutures. Care was taken to avoid placing the entry hole through the bony insertion of the supraspinatus tendon. Through the supraspinatus incision, the guide wire was advanced into the proximal humeral segment. The proximal segment was reduced to the shaft, and the guide wire was advanced across the fracture site. With an awl, the cortex was perforated and the entry hole enlarged. The proximal humeral segment was broached and the cannulated Polaris nail was inserted over the guide. The nail was advanced until just below the articular surface to avoid impingement of the subacromial space. Once satisfactory reduction was confirmed fluoroscopically, the nail was statically locked with up to five 5.0-mm cancellous screws proximally and two 3.5-mm cortical screws distally, with the use of a radiolucent targeting guide. If the tuberosity was displaced, it was reduced with traction sutures prior to fixation with 1 or more proximal locking screws. If necessary, tuberosity fixation was augmented with heavy nonabsorbable sutures. The final reduction was verified fluoroscopically. Lastly, the supraspinatus tendon split was repaired with
B.M. Nolan et al. interrupted #2 nonabsorbable sutures in a side-to-side fashion. The wound was closed in layers. A sling was used for 6 weeks. The postoperative rehabilitation protocol began with passive and active assisted range of motion exercises immediately after surgery, followed by active exercises at 4-6 weeks and strengthening at 6-8 weeks. Patients were evaluated at 2 and 6 weeks postoperatively and thereafter at 3-month intervals until fracture union was confirmed clinically and radiographically. A standard 3-view Neer shoulder trauma series was completed at each postoperative visit. All views were taken in standard position by a single x-ray technologist, who is trained in shoulders. These views included an anterior posterior (AP) view in the plane of the glenohumeral joint, with the humerus held in 20 of external rotation, an axillary view, and a lateral scapular ‘Y’ view. Any inadequate views were repeated until standardized films were obtained. Radiographic results were evaluated for fracture union, alignment, and hardware loosening. Neck/shaft angle was determined using the humeral shaft axis and perpendicular to the articular segment or anatomic neck of the humerus. Malunion was defined as a neck/shaft angle less than 120 or greater than 150 .5 Nonunion was defined as lack of radiographic or clinical union at a minimum 6 months after surgery. Functional evaluation was assessed with the use of the American Shoulder and Elbow Surgeons (ASES) and Constant scores and Simple Shoulder Test (SST).5,11 ASES scores were graded as excellent (91-100 points), good (81-90 points), fair (7180 points), or poor (70 points or less). Constant scores were graded as excellent (90-100 points), good (80-89 points), satisfactory (70-79 points), or fair (less than 70 points). Patients were also assessed for evidence of rotator cuff disease with Neer’s sign, Hawkin’s sign, arc of pain, supraspinatus/greater tuberosity tenderness, abduction strength, external rotation strength, subacromial crepitus, drop arm sign, external rotation lag sign, and the lift-off sign. As a secondary comparison, patients were divided according to fracture type: 2- versus 3-part. The 2 groups were compared in terms of their clinical and radiographic outcomes to determine whether better outcomes could be expected in simpler fracture types.
Statistical analysis Based on the distributional assumptions of the statistical tests being used to analyze a given variable, parametric, nonparametric, or exact statistical tests were used to analyze the data. Normally distributed continuous variables were analyzed using the Student t test; non-normally distributed continuous variables were analyzed using the Wilcoxon 2-sample test based on the t approximation. Nominal categorical variables were analyzed using the 2-tailed Fisher exact test, while ordinal categorical variables were analyzed using the Mantel-Haenszel chi-square test. P values less than an alpha of .05 (probability of type I error) were considered statistically significant.
Results Radiographic results were available for all 18 patients. Of the 18 patients with complete radiographic data, 2
Intramedullary nailing of proximal humerus fractures Table I
Demographic information for all patients
Patient Age Gender Fractured Mechanism side of injury
Classification
KM JD BM GI RM HF MG IJ JK VK MDI BG MD ML WG SF HC BS
2-part 2-part 2-part 2-part 2-part 2-part 2-part 2-part 2-part 3-part 3-part 3 Part 3 Part 3 Part 2 Part 3 Part 2 Part 2 Part
80 73 72 84 67 72 75 83 76 63 60 60 60 82 44 37 77 46
M M F F F F F F M F F F F F M M F F
Left Right Right Left Left Right Right Right Left Right Right Left Left Left Left Left Left Right
Fall Fall Fall Fall Fall Fall Hit by truck Fall Fall Fall Motorcycle Fall Fall Fall Fall Fall Fall Fall
expired, 1 was lost to follow-up, 1 was unable to participate due to severe dementia, and 1 refused to participate. This left 13 patients available for final clinical evaluations with an average follow-up of 42 months (range, 24-84). The mean age was 71 years (range, 37-84). Thirteen patients were females and 5 patients were males. Seven of the fractures involved the dominant extremity. Preoperative radiographs were used to classify the fractures according to the Neer classification of proximal humeral fractures.13 Of the complete group of 18 patients, 12 were 2-part surgical neck fractures and 6 were 3-part greater tuberosity fractures. Of the 13 patients available for clinical follow-up, 9 were 2-part surgical neck fractures and 4 were 3-part greater tuberosity fractures. Demographics and fracture classification for all patients are included in Table I. There were no significant differences with respect to age, gender, or time to surgery between the 2- and 3-part fracture groups. Radiographs were reviewed for union, alignment, and hardware loosening. Seventeen of 18 patients (94%) healed. The mean initial and final postoperative neck/shaft angle measurements for all patients are shown in Table II. During healing, the neck/shaft angle collapsed an average 11 (range, 5-30 ) into varus. Nine of 18 (50%) had final neck/ shaft angles <120 and were considered radiographic malunions. Five out of 6 (83%) 3-part and 4 out of 12 (33%) 2-part proximal humerus fractures were considered radiographic malunions (Table III). Varus collapse is shown in Figure, A and B. Ten of 18 patients (50%) had positive greater tuberosity to humeral head measurements, indicating the greater tuberosity had healed proud in a nonanatomic position higher or superior to the articular segment. Clinical results for all patients are summarized in Table IV. Mean ASES score was 67 and mean Constant
1243 Table II
Radiographic outcomes for all patients
Patient
Union
Initial neck-shaft angle
Final neck-shaft angle
GT-HH distance (mm))
KM JD BM GI RM HF MG IJ JK VK MDI BG MD ML WG SF HC BS
Yes Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes Yes Yes Yes Yes Yes Yes
125 130 130 130 130 130 120 145 150 130 125 130 130 125 130 126 130 140
119 90 119 130 125 110 120 145 150 130 125 130 130 125 130 126 130 140
þ4 7 þ4 2 þ7 0 þ7 þ8 þ6 4 7 þ5 4 3 þ2 þ2 3 þ5
)
Greater Tuberosity to Humeral Head Distance (GT-HH). A positive value denotes that the superior tip of the greater tuberosity is superior to the humeral head. A negative value denotes that the most superior aspect of the humeral head is superior to the tip of the greater tuberosity.
score was 61. Patients could only perform an average 6 out of 12 tasks on the SST. Patients rated their pain an average of 2.3 on a 0-10 scale. Patients had an average of 5/8 positive physical examination signs for rotator cuff disease. At the time of the original operation, 1 patient (HC) had a chronic appearing 2 x 3-cm tear of the supraspinatus tendon. One additional patient (JD) had a ruptured long head of the biceps tendon, with an intact rotator cuff. Of those patients who underwent reoperation, 2 were noted to have rotator cuff tears at reoperation. VK had deficiency of the tuberosities and massive rotator cuff tear at the time of revision to hemiarthroplasty, and BM had a low grade articular-sided partial tear of the supraspinatus tendon. Upon secondary comparison among fracture types, better outcomes were seen with 2-part fractures than 3-part ones (Table V). Seven patients underwent reoperation for hardware removal due to loss of fixation or prominent hardware and 1 patient also underwent revision to a hemiarthroplasty, for an overall reoperation rate of 39%. There were no infections and no neurovascular injuries.
Discussion Nondisplaced or minimally displaced fractures of the proximal humerus can be treated with conservative management with good results.3,13,16,20 Displaced or
1244 Table III
B.M. Nolan et al. Radiographic measurements by fracture type: 2- vs 3-part
Average initial neck-shaft angle (degrees) Final neck-shaft angle
2 part (n ¼ 12)
3 part (n ¼ 6)
P value
132.5 (range, 120-150)
127.67 (range, 125-130)
.1672
124.42 (range, 90-150)
113.83 (range, 100-130)
.1742
unstable fractures can be difficult to treat and often result in stiffness, impaired function, and prolonged morbidity if not managed appropriately. There are many fixation options available; however, no clear consensus exists regarding optimal surgical stabilization. Recent literature has suggested intramedullary nailing may be a less invasive option with comparable biomechanical stability to plate fixation.2,10,12,14,16 The Polaris nail is a device designed specifically for fixation of proximal humerus fractures that has shown promising biomechanical stability.19 Ruch et al demonstrated that intramedullary nailing was equivalent to plate and screw constructs in both cantilever bending and torsional stiffness.17 Published series of patients managed with the intrameduallary nails have shown satisfactory clinical results.2,10,15,21 Lin et al reported a series of 21 patients successfully treated with an antegrade intramedullary nail.10 All fractures healed, and only 1 nail had to be removed for prominence in the subacromial space. Adedapo and Ikpeme reviewed 23 patients with acute 3- and 4-part fractures of the proximal humerus treated with a Polaris nail, and reported a 100% union rate.1 However, 3 patients in the 4-part fracture group continued to have significant pain at final review, including 1 patient who developed avascular necrosis. Rajasekhar et al reported a 97% union rate, with 80% satisfactory to excellent results, in 30 proximal humerus fractures stabilized with a Polaris nail.15 They found no difference in Constant scores based on age. Our results do not support those of previous investigations suggesting a high percentage of satisfactory outcomes following fixation of proximal humerus fractures with the Polaris nail, particularly for fractures with displacement of the tuberosities. This study shows a higher than reported percentage of unsatisfactory results using the Polaris nail and a higher reoperation rate. Our study reports a similar high union rate (17 out of 18 patients; 94%), but also addresses the loss of reduction during healing, resulting in a 50% malunion rate, which has not been emphasized by previous authors. Overall, there were 4 good or excellent outcomes, according to ASES score, in the 13 patients with complete follow-up (31%), and 9 fair or poor outcomes. Kazakos et al report 78% good to excellent results, according to Neer score, with no significant difference between 2- and 3-part fractures.8 Zhu et al21 recently reported good results in 2-part surgical neck fractures. Our series included both 2- and 3-part fractures, so it is possible the inclusion of
Figure (A) Initial postoperative X-ray of 2-part surgical neck fracture. (B) Two months postoperative X-ray of the same patient now with varus malunion measuring 95 .
3-part fractures explains the worse results in our series. In our series, 2-part fractures fared better than 3-part ones, with 4 out of 9 patients (44%) with good to excellent results. There were no good or excellent results in 3-part fractures. These comparisons, however, were not statistically significant. Agel et al recently reported on 20 patients with acute proximal humerus fractures who were treated with the Polaris nail.2 Only 11 healed without complication. Three patients had proximal screw loosening and 2 required revision surgery for proximal fixation failure. The authors
Intramedullary nailing of proximal humerus fractures Table IV
1245
Clinical outcomes for all patients
Patient
SST
ASES score
Constant score
VAS pain
Impingement Signs (out of 8)
Active forward elevation
Active external rotation
Active internal rotation
Reoperation
KM JD BM GI RM HF MG IJ JK VK MDI BG MD ML WG SF HC BS
11 12 4 6 5 11 2 3 12 0 7 7 9
98 100 48 64 78 100 27 45 98 10 56 78 80
72 100 56 53 50 76 30 40 90 24 49 75 72
0 0 2 1 0 0 8 2 0 9 6 1 1
0 0 2 1 0 0 8 2 0 9 6 1 1
100 180 110 90 95 170 70 80 160 65 90 180 170
20 50 70 35 45 70 10 35 25 10 20 70 45
L1 T9 L2 L4 L2 T10 L5 L4 T9 L4 T12 T4 L1
Y Y Y N Y N N N N Y Y Y N N N Y N N
SST, simple shoulder test; ASES, american shoulder and elbow surgeons; VAS; visual analog scale.
state that in the setting of an unstable or comminuted lateral metaphyseal fracture, a poor entry point can contribute to fixation failure and fracture displacement;2 our radiographic measurements, indicating a high incidence of varus collapse, support this assertion. The only paper thus far to evaluate both radiographic and clinical outcomes found 79% good to excellent results, with 8% incidence each of varus malunion and greater tuberosity malalignment.9 Unfortunately, the authors report clinical outcomes using only the Japanese Orthopaedic Association score, which is unfamiliar to many surgeons. We used several standardized, globally accepted validated shoulder instruments to report clinical outcomes (Constant score, ASES, and SST). This study had 4 out of 13 good to excellent (31%), 3 fair (23%), and 6 poor (46%) results at follow-up based on ASES score. According to Constant score, there were 2 good to excellent (15%), 4 satisfactory (31%), and 7 fair (50%) results overall. Radiographically, 50% of the patients in the current study were considered to have healed in nonanatomic positions. The neck/shaft angles collapsed an average 11 into varus postoperatively, with 10 of 18 (56%) patients with final neck/shaft angles of <120 . Nine of 18 patients (50%) had a positive greater tuberosity to humeral head measurement, which indicates superior displacement of the greater tuberosity. Normally, the humeral articular surface projects 5-10 mm higher than the greater tuberosity. Nonanatomic prominence of the greater tuberosity can lead to subacromial impingement and rotator cuff symptoms. In addition, 7 fractures (39%) collapsed with hardware migration, which required reoperation for removal of loose or painful hardware. One such patient
suffered complete loss of proximal fixation with 100% displacement of the humeral head, requiring revision to a hemiarthroplasty at 1 month after the initial surgery. Hardware failure, symptomatic hardware requiring removal, and avascular necrosis of the humeral head following Polaris nail fixation have all been reported by other authors.1,2,8-10,15,18 A study by Sosef et al reported complications in 9/28 patients, with 6 requiring reoperation.18 Radiographic malunion was not evaluated, and thus not included in their report of complications. Our study shows when other factors such as radiographic malunion and rotator cuff symptoms are taken into account, the true rate of complications is higher than previously reported. Ours is the first study to correlate the use of the Polaris nail with rotator cuff symptoms. Our results demonstrated a high incidence of rotator cuff symptoms and weakness, which negatively affected the final functional outcome. Studies of healing rates after rotator cuff repair have demonstrated nonhealing rates up to 80%.4,6,7 It is possible that some of the patients in this series had nonhealing of the rotator cuff tenotomy for insertion of the nail, although no patient desired further imaging. The high rate of varus collapse and positive greater tuberosity to humeral head distances, as well as hardware migration, undoubtedly contributed to subacromial impingement in this series. Although no patient in our series desired further imaging evaluation of the healing status of the supraspinatus tenotomy, an ultrasound may be helpful in those patients desiring further work-up, as the metal from the nail may obscure MRI evaluation. Limitations of the current study are its retrospective nature and relatively small sample size. A main reason for the small
1246 Table V
B.M. Nolan et al. Clinical outcomes by fracture type: 2- vs 3-part
SST score ASES score Constant score Active forward Elevation Active external Rotation Re-operation rate
2 part (n ¼ 12)
3 part (n ¼ 6)
P value
7.33 (range, 2-12) 73.13 (range, 27-100) 63 (range, 30-100) 117.22 (range, 70-180) 40 (range, 10-70) 33.33%
5.75 (range, 0-9) 56.08 (range, 10-80) 55 (range, 24-75) 126.25 (range, 65-180) 36.25 (range, 10-70) 66.67%
.5313 .3557 .5792 .7519 .7885 .3213
SST, simple shoulder test; ASES, american shoulder and elbow Surgeons.
sample size was that we abandoned use of the Polaris nail after a short period of time when the high rate of unsatisfactory results became apparent. While complete radiographic results were available for all patients in the study, we are unable to present functional results for 5 of 18 patients who were lost to follow-up before 2 years. In addition, we are not able to present baseline data to compare with the postoperative data since the patients presented for the first time after sustaining a fracture. Finally, because these patients were undergoing a semi-urgent, nonelective procedure, it was not possible to include a control group. Despite these limitations, this is the first study to critically examine functional results according to several accepted shoulder outcome measures with an emphasis on rotator cuff symptomatology, and to report the high rate of unsatisfactory results with use of the Polaris nail for treatment of displaced proximal humerus fractures. It is possible that the age of our patient population (average 71 years) predisposes to rotator cuff pathology. However, age has not yet been determined to be a factor in healing of a supraspinatus tenotomy, and our population represents the demographic most likely to suffer proximal humerus fractures. Although the setting is a Level 1 trauma center with a large amount of tertiary referrals, the authors believe the patients, fractures, and operative indications included in this series are typical of proximal humerus fractures seen in the orthopaedic community, given the average age of 71 years, predominantly low-energy mechanism of injury, and nonoperative treatment in patients with minimally displaced fractures.
Conclusion Displaced fractures of the proximal humerus are difficult to treat, with a multitude of surgical options available. The Polaris nail was designed to provide fixation of proximal humerus fractures while avoiding some of the complications associated with more traditional means of fixation, such as stiffness, hardware problems, and devascularization of the fracture fragments. However, the device relies mostly upon cancellous bone purchase in the humeral head and does not provide rigid fixation of the humeral head and tuberosities, and, therefore, is unable to resist the
deforming forces acting upon the fractured tuberosities and humeral head. This study has documented a high rate of varus collapse and hardware problems postoperatively that lead to an unacceptable rate of malunion and reoperation. The device is particularly ill suited for stabilization of 3-part fractures, which require placement of the nail through or very near the fracture lines. An additional disadvantage of the Polaris nail is that it requires violation of the rotator cuff insertion for its use. Sequelae of tenotomy of the supraspinatus tendon have not been emphasized in previously published reports on the Polaris nail. Nonhealing of the rotator cuff tenotomy or subacromial irritation from sutures or hardware prominence can lead to pain, stiffness, and patient dissatisfaction despite radiographic healing of the fracture. For these reasons, the senior authors have abandoned use of the Polaris nail for patients with displaced proximal humerus fractures. Newer, more rigid means of fixation such as low profile locking anatomic plates contoured to the proximal humerus, which do not violate the rotator cuff, may provide a more satisfactory means of treating these difficult fractures.
Acknowledgment The authors wish to acknowledge Mamtha Balasubramaniam, MS, for her assistance with statistical analysis, and Matthew J. Siskosky, MD, for his assistance with data collection.
Disclaimer The authors, their immediate families, and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article. No outside funding or grants were received that assisted this study.
Intramedullary nailing of proximal humerus fractures
References 1. Adedapo AO, Ikpeme JO. The results of internal fixation of three- and four-part proximal humeral fractures with the Polaris nail. Injury 2001;32:115-21. 2. Agel J, Jones CB, Sanzone AG, Camuso M, Henley MB. Treatment of proximal humeral fractures with Polaris nail fixation. J Shoulder Elbow Surg 2004;13:191-5. doi:10.1016/j.jse.2003.12.005 3. Bigliani LU, Flatow EL, Pollock RG. Fractures of the proximal humerus. In: Rockwood CA Jr, Green DP, Bucholz RW, Heckman JD, editors. Rockwood and Green’s fractures in adults. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1996. p. 1055-107. 4. Boileau P, Brassart N, Watkinson DJ, Carles M, Hatzidakis AM, Krishnan SG. Arthroscopic repair of full-thickness tears of the supraspinatus: does the tendon really heal? J Bone Joint Surg Am 2005;87:1229-40. doi:10.2106/JBJS.D.02035 5. Constant CR, Murley AH. A clinical method of functional assessment of the shoulder. Clin Orthop Relat Res 1987;214:160-4. 6. Galatz LM, Ball CM, Teefey SA, Middleton WD, Yamaguchi K. The outcome and repair integrity of completely arthroscopically repaired large and massive rotator cuff tears. J Bone Joint Surg Am 2004;86-A:219-24. 7. Jost B, Pfirrmann CW, Gerber C. Clinical outcome after structural failure of rotator cuff repairs. J Bone Joint Surg Am 2000;82:304-14. 8. Kazakos D, Lyras DN, Galanis V, Verettas D, Psillikas I, Chatzipappas Ch, et al. Internal fixation of proximal humerus fractures using the Polaris intramedullary nail. Arch Orthop Trauma Surg 2007; 127:503-8. doi:10.1007/s00402-007-0390-z 9. Kelke Y, Komatsuda T, Sato K. Internal fixation of proximal humeral fractures with a Polaris humeral nail. J Orthop Trauma 2008;9:135-9. doi:10.1007/s10195-008-0019-1 10. Lin J, Hou SM, Hang YS. Locked nailing for displaced surgical neck fractures of the humerus. J Trauma 1998;45:1051-7.
1247 11. Michener LA, McClure PW, Sennett BJ. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, patient self-report section: reliability, validity, and responsiveness. J Shoulder Elbow Surg 2002;11:587-94. doi:10.1067/mse.2002.127096 12. Molster A, Gjerdet NR, Strand RM, Hole RM, Hove LM. Intramedullary nailing in humeral shaft fractures. Mechanical behavior in vitro after osteosynthesis with three different intramedullary nails. Arch Orthop Trauma Surg 2001;121:554-6. 13. Neer CS II. Displaced proximal humeral fractures. I. Classification and evaluation. J Bone Joint Surg Am 1970;52:1077-89. 14. Parsons M, O’Brien RJ, Hughes JS. Locked intramedullary nailing for displaced and unstable proximal humerus fractures. Tech Shoulder Elbow Surg 2005;6:75-86. 15. Rajasekhar C, Ray PS, Bhamra MS. Fixation of proximal humeral fractures with the Polaris nail. J Shoulder Elbow Surg 2001;10:7-10. 16. Rasmussen S, Hvass I, Dalsgaard J, Christensen BS, Holstad E. Displaced proximal humeral fractures: results of conservative treatment. Injury 1992;23:41-3. 17. Ruch DS, Glisson RR, Marr AW, Russell GB, Nunley JA. Fixation of three-part proximal humeral fractures: a biomechanical evaluation. J Orthop Trauma 2000;14:36-40. 18. Sosef N, Stobbe I, Hogervorst M, Mommers L, Verbruggen J, van der Elst M, et al. The Polaris intramedullary nail for proximal humerus fractures: outcome in 28 patients followed for 1 year. Acta Orthop 2007;78:436-41. doi:10.1080/17453670710014040 19. Wheeler DL, Colville MR. Biomechanical comparison of intramedullary and percutaneous pin fixation for proximal humeral fracture fixation. J Orthop Trauma 1997;11:363-7. 20. Young TB, Wallace WA. Conservative treatment of fractures and fracture-dislocations of the upper end of the humerus. J Bone Joint Surg Br 1985;67:373-7. 21. Zhu Y, Lu Y, Wang M, Jiang C. Treatment of proximal humeral fracture with a proximal humeral nail. J Shoulder Elbow Surg 2010; 19:297-302. doi:10.1016/j.jse.2009.05.013
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Surgical treatment of displaced proximal humerus fractures with a short intramedullary nail Betsy M. Nolan, MDa, Matthew A. Kippe, MDb, J. Michael Wiater, MDc,*, Gregory P. Nowinski, MDc a
Indiana University School of Medicine, Indianapolis, IN, USA Sports Medicine and Shoulder Surgery, Hawthorn Medical Associates, North Dartmouth, MA, USA c Department of Orthopaedic Surgery, William Beaumont Hospital, Royal Oak, MI, USA b
Background: The Polaris nail is an intramedullary device for treating displaced proximal humerus fractures with few published studies to support its use. Results of a consecutive series of patients treated with the Polaris nail are presented. Methods: Eighteen patients with a mean age of 71 years (range, 37-84) were treated for twelve 2- and six 3-part fractures. Radiographic results for all patients were evaluated. Thirteen patients with an average follow-up of 42 months (range, 24-84) were available for functional evaluation. Results: Seventeen of 18 patients healed. Postoperatively, the neck/shaft angle collapsed an average 11 (range, 5-30 ) into varus. Nine of 18 patients had final neck/shaft angles <120 and were considered radiographic malunions. The mean Constant and American Shoulder and Elbow Surgeons (ASES) scores were 61 (range, 20-100) and 67 (range, 10-100), respectively. Forward elevation averaged 118 . Patients had an average 5/8 positive rotator cuff signs. Seven patients underwent reoperation for loss of fixation or prominent hardware, and 1 required revision to a hemiarthroplasty. Conclusion: This study shows a higher than reported percentage of unsatisfactory results using the Polaris nail. The device violates the rotator cuff and is unable to resist the deforming forces that can lead to loss of fixation and varus collapse. Level of evidence: Level IV, Case Series, Treatment Study. Ó 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. Keywords: Proximal humerus fracture; intramedullary nail; malunion; rotator cuff; shoulder; fracture Polaris nail
Proximal humerus fractures are common injuries. Most proximal humerus fractures are minimally displaced and can be treated successfully without surgery.3,13,16,20 Less This study was approved by the Human Investigation Committee: # 2003228. *Reprint requests: J. Michael Wiater, MD, Chief of Shoulder Surgery, Department of Orthopaedic Surgery, William Beaumont Hospital, 3601 West Thirteen Mile Road, Royal Oak, MI 48073, USA. E-mail address: [email protected] (J.M. Wiater).
commonly, displaced or unstable fractures may require surgical management. With an aging population and associated increased prevalence of osteoporosis, the incidence of proximal humerus fractures will increase as will the number that require operative fixation. A variety of treatment options for surgical treatment of proximal humerus fractures are currently available, including nonlocking plate and screws, locking plate and screws, intramedullary nails, Enders rods, percutaneous pinning, blade plate and screws, heavy suture
1058-2746/$ - see front matter Ó 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. doi:10.1016/j.jse.2010.12.010
1242 fixation, tension band wiring, and prosthetic arthroplasty. Moreover, no consensus exists over which technique is the best for managing these challenging fractures. The Polaris nail (Acumed, Beaverton, OR) is an 11.0 x 150-mm titanium nonreamed antegrade intramedullary device designed for stabilization of proximal humerus fractures. Previous studies have reported good clinical and radiographic outcomes for both young and elderly patients with the use of this device.2,10,16 We present a consecutive series of patients with proximal humerus fractures treated with the Polaris nail. The purpose of this study was to evaluate both radiographic and functional results of the Polaris nail and to compare those results with previously published data. We hypothesize that Polaris nail fixation of 2- and 3-part proximal humerus fractures results in high rates of both varus malunion and unsatisfactory clinical outcome.
Materials and methods Eighteen patients with unilateral displaced proximal humerus fractures were treated with reduction and stabilization using a short, nonreamed antegrade interlocking intramedullary nail by the senior authors (GPN and JMW) between 1997 and 2002. The mechanism of injury was a low-energy fall in 16 and a high-energy motor vehicle accident in 2. Exclusion criteria included minimally displaced fractures, displaced 4-part fractures, unacceptable medical risks for surgery, and refusal of operative treatment. Radiographic and clinical results were retrospectively reviewed. General anesthesia, interscalene regional anesthesia, or a combination of both was performed. The beach chair position was utilized, with the operative extremity draped free. A superior skin incision was placed approximately 1 cm lateral to the anterolateral border of the acromion. The lateral deltoid muscle was split in line with its fibers. Traction sutures were placed around the tuberosity fragments according to the fracture pattern. Under fluoroscopic guidance, the entry point for the nail was localized with a 2.0-mm guide wire. This was typically through the supraspinatus tendon posterior to the long head of the biceps tendon, and just onto the humeral articular surface medial to the greater tuberosity. The supraspinatus tendon was then incised longitudinally and the tendon edges tagged with traction sutures. Care was taken to avoid placing the entry hole through the bony insertion of the supraspinatus tendon. Through the supraspinatus incision, the guide wire was advanced into the proximal humeral segment. The proximal segment was reduced to the shaft, and the guide wire was advanced across the fracture site. With an awl, the cortex was perforated and the entry hole enlarged. The proximal humeral segment was broached and the cannulated Polaris nail was inserted over the guide. The nail was advanced until just below the articular surface to avoid impingement of the subacromial space. Once satisfactory reduction was confirmed fluoroscopically, the nail was statically locked with up to five 5.0-mm cancellous screws proximally and two 3.5-mm cortical screws distally, with the use of a radiolucent targeting guide. If the tuberosity was displaced, it was reduced with traction sutures prior to fixation with 1 or more proximal locking screws. If necessary, tuberosity fixation was augmented with heavy nonabsorbable sutures. The final reduction was verified fluoroscopically. Lastly, the supraspinatus tendon split was repaired with
B.M. Nolan et al. interrupted #2 nonabsorbable sutures in a side-to-side fashion. The wound was closed in layers. A sling was used for 6 weeks. The postoperative rehabilitation protocol began with passive and active assisted range of motion exercises immediately after surgery, followed by active exercises at 4-6 weeks and strengthening at 6-8 weeks. Patients were evaluated at 2 and 6 weeks postoperatively and thereafter at 3-month intervals until fracture union was confirmed clinically and radiographically. A standard 3-view Neer shoulder trauma series was completed at each postoperative visit. All views were taken in standard position by a single x-ray technologist, who is trained in shoulders. These views included an anterior posterior (AP) view in the plane of the glenohumeral joint, with the humerus held in 20 of external rotation, an axillary view, and a lateral scapular ‘Y’ view. Any inadequate views were repeated until standardized films were obtained. Radiographic results were evaluated for fracture union, alignment, and hardware loosening. Neck/shaft angle was determined using the humeral shaft axis and perpendicular to the articular segment or anatomic neck of the humerus. Malunion was defined as a neck/shaft angle less than 120 or greater than 150 .5 Nonunion was defined as lack of radiographic or clinical union at a minimum 6 months after surgery. Functional evaluation was assessed with the use of the American Shoulder and Elbow Surgeons (ASES) and Constant scores and Simple Shoulder Test (SST).5,11 ASES scores were graded as excellent (91-100 points), good (81-90 points), fair (7180 points), or poor (70 points or less). Constant scores were graded as excellent (90-100 points), good (80-89 points), satisfactory (70-79 points), or fair (less than 70 points). Patients were also assessed for evidence of rotator cuff disease with Neer’s sign, Hawkin’s sign, arc of pain, supraspinatus/greater tuberosity tenderness, abduction strength, external rotation strength, subacromial crepitus, drop arm sign, external rotation lag sign, and the lift-off sign. As a secondary comparison, patients were divided according to fracture type: 2- versus 3-part. The 2 groups were compared in terms of their clinical and radiographic outcomes to determine whether better outcomes could be expected in simpler fracture types.
Statistical analysis Based on the distributional assumptions of the statistical tests being used to analyze a given variable, parametric, nonparametric, or exact statistical tests were used to analyze the data. Normally distributed continuous variables were analyzed using the Student t test; non-normally distributed continuous variables were analyzed using the Wilcoxon 2-sample test based on the t approximation. Nominal categorical variables were analyzed using the 2-tailed Fisher exact test, while ordinal categorical variables were analyzed using the Mantel-Haenszel chi-square test. P values less than an alpha of .05 (probability of type I error) were considered statistically significant.
Results Radiographic results were available for all 18 patients. Of the 18 patients with complete radiographic data, 2
Intramedullary nailing of proximal humerus fractures Table I
Demographic information for all patients
Patient Age Gender Fractured Mechanism side of injury
Classification
KM JD BM GI RM HF MG IJ JK VK MDI BG MD ML WG SF HC BS
2-part 2-part 2-part 2-part 2-part 2-part 2-part 2-part 2-part 3-part 3-part 3 Part 3 Part 3 Part 2 Part 3 Part 2 Part 2 Part
80 73 72 84 67 72 75 83 76 63 60 60 60 82 44 37 77 46
M M F F F F F F M F F F F F M M F F
Left Right Right Left Left Right Right Right Left Right Right Left Left Left Left Left Left Right
Fall Fall Fall Fall Fall Fall Hit by truck Fall Fall Fall Motorcycle Fall Fall Fall Fall Fall Fall Fall
expired, 1 was lost to follow-up, 1 was unable to participate due to severe dementia, and 1 refused to participate. This left 13 patients available for final clinical evaluations with an average follow-up of 42 months (range, 24-84). The mean age was 71 years (range, 37-84). Thirteen patients were females and 5 patients were males. Seven of the fractures involved the dominant extremity. Preoperative radiographs were used to classify the fractures according to the Neer classification of proximal humeral fractures.13 Of the complete group of 18 patients, 12 were 2-part surgical neck fractures and 6 were 3-part greater tuberosity fractures. Of the 13 patients available for clinical follow-up, 9 were 2-part surgical neck fractures and 4 were 3-part greater tuberosity fractures. Demographics and fracture classification for all patients are included in Table I. There were no significant differences with respect to age, gender, or time to surgery between the 2- and 3-part fracture groups. Radiographs were reviewed for union, alignment, and hardware loosening. Seventeen of 18 patients (94%) healed. The mean initial and final postoperative neck/shaft angle measurements for all patients are shown in Table II. During healing, the neck/shaft angle collapsed an average 11 (range, 5-30 ) into varus. Nine of 18 (50%) had final neck/ shaft angles <120 and were considered radiographic malunions. Five out of 6 (83%) 3-part and 4 out of 12 (33%) 2-part proximal humerus fractures were considered radiographic malunions (Table III). Varus collapse is shown in Figure, A and B. Ten of 18 patients (50%) had positive greater tuberosity to humeral head measurements, indicating the greater tuberosity had healed proud in a nonanatomic position higher or superior to the articular segment. Clinical results for all patients are summarized in Table IV. Mean ASES score was 67 and mean Constant
1243 Table II
Radiographic outcomes for all patients
Patient
Union
Initial neck-shaft angle
Final neck-shaft angle
GT-HH distance (mm))
KM JD BM GI RM HF MG IJ JK VK MDI BG MD ML WG SF HC BS
Yes Yes Yes Yes Yes Yes Yes Yes Yes No Yes Yes Yes Yes Yes Yes Yes Yes
125 130 130 130 130 130 120 145 150 130 125 130 130 125 130 126 130 140
119 90 119 130 125 110 120 145 150 130 125 130 130 125 130 126 130 140
þ4 7 þ4 2 þ7 0 þ7 þ8 þ6 4 7 þ5 4 3 þ2 þ2 3 þ5
)
Greater Tuberosity to Humeral Head Distance (GT-HH). A positive value denotes that the superior tip of the greater tuberosity is superior to the humeral head. A negative value denotes that the most superior aspect of the humeral head is superior to the tip of the greater tuberosity.
score was 61. Patients could only perform an average 6 out of 12 tasks on the SST. Patients rated their pain an average of 2.3 on a 0-10 scale. Patients had an average of 5/8 positive physical examination signs for rotator cuff disease. At the time of the original operation, 1 patient (HC) had a chronic appearing 2 x 3-cm tear of the supraspinatus tendon. One additional patient (JD) had a ruptured long head of the biceps tendon, with an intact rotator cuff. Of those patients who underwent reoperation, 2 were noted to have rotator cuff tears at reoperation. VK had deficiency of the tuberosities and massive rotator cuff tear at the time of revision to hemiarthroplasty, and BM had a low grade articular-sided partial tear of the supraspinatus tendon. Upon secondary comparison among fracture types, better outcomes were seen with 2-part fractures than 3-part ones (Table V). Seven patients underwent reoperation for hardware removal due to loss of fixation or prominent hardware and 1 patient also underwent revision to a hemiarthroplasty, for an overall reoperation rate of 39%. There were no infections and no neurovascular injuries.
Discussion Nondisplaced or minimally displaced fractures of the proximal humerus can be treated with conservative management with good results.3,13,16,20 Displaced or
1244 Table III
B.M. Nolan et al. Radiographic measurements by fracture type: 2- vs 3-part
Average initial neck-shaft angle (degrees) Final neck-shaft angle
2 part (n ¼ 12)
3 part (n ¼ 6)
P value
132.5 (range, 120-150)
127.67 (range, 125-130)
.1672
124.42 (range, 90-150)
113.83 (range, 100-130)
.1742
unstable fractures can be difficult to treat and often result in stiffness, impaired function, and prolonged morbidity if not managed appropriately. There are many fixation options available; however, no clear consensus exists regarding optimal surgical stabilization. Recent literature has suggested intramedullary nailing may be a less invasive option with comparable biomechanical stability to plate fixation.2,10,12,14,16 The Polaris nail is a device designed specifically for fixation of proximal humerus fractures that has shown promising biomechanical stability.19 Ruch et al demonstrated that intramedullary nailing was equivalent to plate and screw constructs in both cantilever bending and torsional stiffness.17 Published series of patients managed with the intrameduallary nails have shown satisfactory clinical results.2,10,15,21 Lin et al reported a series of 21 patients successfully treated with an antegrade intramedullary nail.10 All fractures healed, and only 1 nail had to be removed for prominence in the subacromial space. Adedapo and Ikpeme reviewed 23 patients with acute 3- and 4-part fractures of the proximal humerus treated with a Polaris nail, and reported a 100% union rate.1 However, 3 patients in the 4-part fracture group continued to have significant pain at final review, including 1 patient who developed avascular necrosis. Rajasekhar et al reported a 97% union rate, with 80% satisfactory to excellent results, in 30 proximal humerus fractures stabilized with a Polaris nail.15 They found no difference in Constant scores based on age. Our results do not support those of previous investigations suggesting a high percentage of satisfactory outcomes following fixation of proximal humerus fractures with the Polaris nail, particularly for fractures with displacement of the tuberosities. This study shows a higher than reported percentage of unsatisfactory results using the Polaris nail and a higher reoperation rate. Our study reports a similar high union rate (17 out of 18 patients; 94%), but also addresses the loss of reduction during healing, resulting in a 50% malunion rate, which has not been emphasized by previous authors. Overall, there were 4 good or excellent outcomes, according to ASES score, in the 13 patients with complete follow-up (31%), and 9 fair or poor outcomes. Kazakos et al report 78% good to excellent results, according to Neer score, with no significant difference between 2- and 3-part fractures.8 Zhu et al21 recently reported good results in 2-part surgical neck fractures. Our series included both 2- and 3-part fractures, so it is possible the inclusion of
Figure (A) Initial postoperative X-ray of 2-part surgical neck fracture. (B) Two months postoperative X-ray of the same patient now with varus malunion measuring 95 .
3-part fractures explains the worse results in our series. In our series, 2-part fractures fared better than 3-part ones, with 4 out of 9 patients (44%) with good to excellent results. There were no good or excellent results in 3-part fractures. These comparisons, however, were not statistically significant. Agel et al recently reported on 20 patients with acute proximal humerus fractures who were treated with the Polaris nail.2 Only 11 healed without complication. Three patients had proximal screw loosening and 2 required revision surgery for proximal fixation failure. The authors
Intramedullary nailing of proximal humerus fractures Table IV
1245
Clinical outcomes for all patients
Patient
SST
ASES score
Constant score
VAS pain
Impingement Signs (out of 8)
Active forward elevation
Active external rotation
Active internal rotation
Reoperation
KM JD BM GI RM HF MG IJ JK VK MDI BG MD ML WG SF HC BS
11 12 4 6 5 11 2 3 12 0 7 7 9
98 100 48 64 78 100 27 45 98 10 56 78 80
72 100 56 53 50 76 30 40 90 24 49 75 72
0 0 2 1 0 0 8 2 0 9 6 1 1
0 0 2 1 0 0 8 2 0 9 6 1 1
100 180 110 90 95 170 70 80 160 65 90 180 170
20 50 70 35 45 70 10 35 25 10 20 70 45
L1 T9 L2 L4 L2 T10 L5 L4 T9 L4 T12 T4 L1
Y Y Y N Y N N N N Y Y Y N N N Y N N
SST, simple shoulder test; ASES, american shoulder and elbow surgeons; VAS; visual analog scale.
state that in the setting of an unstable or comminuted lateral metaphyseal fracture, a poor entry point can contribute to fixation failure and fracture displacement;2 our radiographic measurements, indicating a high incidence of varus collapse, support this assertion. The only paper thus far to evaluate both radiographic and clinical outcomes found 79% good to excellent results, with 8% incidence each of varus malunion and greater tuberosity malalignment.9 Unfortunately, the authors report clinical outcomes using only the Japanese Orthopaedic Association score, which is unfamiliar to many surgeons. We used several standardized, globally accepted validated shoulder instruments to report clinical outcomes (Constant score, ASES, and SST). This study had 4 out of 13 good to excellent (31%), 3 fair (23%), and 6 poor (46%) results at follow-up based on ASES score. According to Constant score, there were 2 good to excellent (15%), 4 satisfactory (31%), and 7 fair (50%) results overall. Radiographically, 50% of the patients in the current study were considered to have healed in nonanatomic positions. The neck/shaft angles collapsed an average 11 into varus postoperatively, with 10 of 18 (56%) patients with final neck/shaft angles of <120 . Nine of 18 patients (50%) had a positive greater tuberosity to humeral head measurement, which indicates superior displacement of the greater tuberosity. Normally, the humeral articular surface projects 5-10 mm higher than the greater tuberosity. Nonanatomic prominence of the greater tuberosity can lead to subacromial impingement and rotator cuff symptoms. In addition, 7 fractures (39%) collapsed with hardware migration, which required reoperation for removal of loose or painful hardware. One such patient
suffered complete loss of proximal fixation with 100% displacement of the humeral head, requiring revision to a hemiarthroplasty at 1 month after the initial surgery. Hardware failure, symptomatic hardware requiring removal, and avascular necrosis of the humeral head following Polaris nail fixation have all been reported by other authors.1,2,8-10,15,18 A study by Sosef et al reported complications in 9/28 patients, with 6 requiring reoperation.18 Radiographic malunion was not evaluated, and thus not included in their report of complications. Our study shows when other factors such as radiographic malunion and rotator cuff symptoms are taken into account, the true rate of complications is higher than previously reported. Ours is the first study to correlate the use of the Polaris nail with rotator cuff symptoms. Our results demonstrated a high incidence of rotator cuff symptoms and weakness, which negatively affected the final functional outcome. Studies of healing rates after rotator cuff repair have demonstrated nonhealing rates up to 80%.4,6,7 It is possible that some of the patients in this series had nonhealing of the rotator cuff tenotomy for insertion of the nail, although no patient desired further imaging. The high rate of varus collapse and positive greater tuberosity to humeral head distances, as well as hardware migration, undoubtedly contributed to subacromial impingement in this series. Although no patient in our series desired further imaging evaluation of the healing status of the supraspinatus tenotomy, an ultrasound may be helpful in those patients desiring further work-up, as the metal from the nail may obscure MRI evaluation. Limitations of the current study are its retrospective nature and relatively small sample size. A main reason for the small
1246 Table V
B.M. Nolan et al. Clinical outcomes by fracture type: 2- vs 3-part
SST score ASES score Constant score Active forward Elevation Active external Rotation Re-operation rate
2 part (n ¼ 12)
3 part (n ¼ 6)
P value
7.33 (range, 2-12) 73.13 (range, 27-100) 63 (range, 30-100) 117.22 (range, 70-180) 40 (range, 10-70) 33.33%
5.75 (range, 0-9) 56.08 (range, 10-80) 55 (range, 24-75) 126.25 (range, 65-180) 36.25 (range, 10-70) 66.67%
.5313 .3557 .5792 .7519 .7885 .3213
SST, simple shoulder test; ASES, american shoulder and elbow Surgeons.
sample size was that we abandoned use of the Polaris nail after a short period of time when the high rate of unsatisfactory results became apparent. While complete radiographic results were available for all patients in the study, we are unable to present functional results for 5 of 18 patients who were lost to follow-up before 2 years. In addition, we are not able to present baseline data to compare with the postoperative data since the patients presented for the first time after sustaining a fracture. Finally, because these patients were undergoing a semi-urgent, nonelective procedure, it was not possible to include a control group. Despite these limitations, this is the first study to critically examine functional results according to several accepted shoulder outcome measures with an emphasis on rotator cuff symptomatology, and to report the high rate of unsatisfactory results with use of the Polaris nail for treatment of displaced proximal humerus fractures. It is possible that the age of our patient population (average 71 years) predisposes to rotator cuff pathology. However, age has not yet been determined to be a factor in healing of a supraspinatus tenotomy, and our population represents the demographic most likely to suffer proximal humerus fractures. Although the setting is a Level 1 trauma center with a large amount of tertiary referrals, the authors believe the patients, fractures, and operative indications included in this series are typical of proximal humerus fractures seen in the orthopaedic community, given the average age of 71 years, predominantly low-energy mechanism of injury, and nonoperative treatment in patients with minimally displaced fractures.
Conclusion Displaced fractures of the proximal humerus are difficult to treat, with a multitude of surgical options available. The Polaris nail was designed to provide fixation of proximal humerus fractures while avoiding some of the complications associated with more traditional means of fixation, such as stiffness, hardware problems, and devascularization of the fracture fragments. However, the device relies mostly upon cancellous bone purchase in the humeral head and does not provide rigid fixation of the humeral head and tuberosities, and, therefore, is unable to resist the
deforming forces acting upon the fractured tuberosities and humeral head. This study has documented a high rate of varus collapse and hardware problems postoperatively that lead to an unacceptable rate of malunion and reoperation. The device is particularly ill suited for stabilization of 3-part fractures, which require placement of the nail through or very near the fracture lines. An additional disadvantage of the Polaris nail is that it requires violation of the rotator cuff insertion for its use. Sequelae of tenotomy of the supraspinatus tendon have not been emphasized in previously published reports on the Polaris nail. Nonhealing of the rotator cuff tenotomy or subacromial irritation from sutures or hardware prominence can lead to pain, stiffness, and patient dissatisfaction despite radiographic healing of the fracture. For these reasons, the senior authors have abandoned use of the Polaris nail for patients with displaced proximal humerus fractures. Newer, more rigid means of fixation such as low profile locking anatomic plates contoured to the proximal humerus, which do not violate the rotator cuff, may provide a more satisfactory means of treating these difficult fractures.
Acknowledgment The authors wish to acknowledge Mamtha Balasubramaniam, MS, for her assistance with statistical analysis, and Matthew J. Siskosky, MD, for his assistance with data collection.
Disclaimer The authors, their immediate families, and any research foundations with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article. No outside funding or grants were received that assisted this study.
Intramedullary nailing of proximal humerus fractures
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