This study was conducted to compare the radiological and clinical outcomes of internal fixation using a Polarus humeral nail for treatment of a humeral shaft fracture according to fracture types.
From 43 patients, 13 were excluded and 30 patients were included. The 30 patients were divided into 2 groups: 15 in group I (Orthopaedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen classification type A and B) and 15 in group II (type C). The mean age was 63.1 years (range, 20–87 years), and mean follow-up period was 2.3 years (range, 1.0–6.1 years). The causes of injuries were as follows: 12, traffic accidents; 14, simple slips; 2, simple falls; 2, contusions after lower energy trauma. Radiological and clinical evaluations were performed.
Radiological union was confirmed by plain anteroposterior and lateral radiographs on average of 5.0 months in group I, and 8.4 months in group II, respectively. Differences between the two groups were statistically significant (
Intramedullary nailing using the Polarus humeral nail is considered to be a good treatment modality for all types of humeral shaft fractures. Additionally, the Polarus humeral nail can be an optimal choice for the treatment of complex type fractures such as segmental or comminuted humeral shaft fractures.
Humeral fractures account for approximately 5% to 8% of all extreme fractures, and humeral shaft fractures comprise about 3% of these [
Originally, the Polarus intramedullary nail (Acumed LLC, Hillsboro, OR, USA) was developed as a specialized device to treat proximal humeral fractures by allowing screw stabilization in the humeral head and tuberosities [
Between December 2005 and April 2018, one surgeon (CHC) performed internal fixation using a Polarus intramedullary nail over 220 mm in length for treatment of humeral shaft fractures in 43 patients. Of these 43 patients, 13 were excluded for the following reasons: death before 1-year of follow-up (3 patients), follow-up loss (4 patients), pathologic fractures (2 patients), and use of other intramedullary nails (4 patients). Finally, 30 patients (12 males and 18 females) were included in this study. All fractures were classified based on the OTA/AO classification system, and the 3 main fracture types were divided into simple (type A,
Surgery was performed in a beach chair position under general anesthesia for all cases. As a surgical approach for intramedullary nail insertion, a 3 to 5 cm vertical skin incision was performed on the lateral margin of acromion, and then extended parallel to the deltoid muscle fibers. The subdeltoid bursa was excised to visualize the supraspinatus tendon. A longitudinal incision was made 1.5 cm posterior to the biceps muscle near the greater tuberosity to which the supraspinatus muscle attaches to expose the insertion point of the nail. A drill and awl were used to create an insertion point at 1.5 cm posterior to the bicipital groove and the border between the joint surface and greater tuberosity. A nail was then inserted through the medial sulcus of the greater tuberosity to obtain intramedullary access. To prevent subacromial impingement by nail protrusion, the proximal end of the nail was inserted within the articular margin of the humeral head. We did not damage the deltoid branch of the axillary nerve. For complex fractures, two Steinmann pins were inserted into the proximal and distal humeral shaft based on the fracture line, then adjusted to reduce the alignment and rotation of the humeral shaft while viewing the fluoroscopic image. To prevent radial nerve injury, a 2 cm longitudinal incision was conducted in nine cases, and distal screws were inserted after visualizing the pathway of the radial nerve.
All patients wore an abduction brace for 1 month after the operation, and an arm sling was worn for another 1 month after removing the abduction brace. Pendulum, passive elevation and isometric exercises were performed on the first postoperative day when the fixation was firm. At the 1 month follow-up, an active elevation exercise with 90° forward flexion of the glenohumeral joint was performed. At the 6 to 8 weeks follow-up, active exercise was performed according to clinical union time. During the follow-up period, the active exercise was stopped when the migration of proximal screws occurred. After observing pain relief at the surgical site and the degree of screw migration, a decision of whether to resume the exercise was made.
A paired t-test was used to compare the results between groups, including radiological and clinical union, operation time, and KSS. IBM SPSS ver. 23.0 (IBM Corp., Armonk, NY, USA) was utilized for statistical analysis, and a
Institutional review board approval (No. CR-18-128-L) was obtained and informed consent was acquired from all individual patients included in this research. Additionally, all participants of this study agreed to its publication, including that of the attached radiographic images.
All cases progressed to union, resulting in a 100% radiological union rate. Radiological union was confirmed by both plain AP and lateral radiographs at an average of 5.0 months in group I and 8.4 months in group II, respectively. The difference between the two groups was statistically significant (
Nonoperative management is the main treatment method for humeral shaft fracture, and many reports have shown good clinical results after nonoperative treatment for humeral shaft fracture [
Several options for operative management in humeral shaft fracture can be considered because of advances in modalities for internal fixation such as plates, intramedullary nails or external fixation. Each modality can be selected according to various factors such as surgeon preference, fracture pattern, possibility of radial nerve damage, and soft tissue condition [
The most widely used classification in humeral shaft fractures is the OTA/AO combined classification system [
Several studies regarding management of humeral shaft fractures with intramedullary nailing have raised various complications. Issues pertaining to intramedullary nailing include insertion site morbidity, subacromial impingement and reoperation rate [
Radial nerve injury, which occurs in up to 18% of closed injuries [
The loosening of proximal cancellous screws reportedly occurs in 4% to 20% of cases [
It should be noted that there are several limitations to this study. Specifically, it is difficult to generalize the results of the research because only 30 cases were considered. In addition, it was also a retrospective comparative study, and the patient assignments were not randomized. Moreover, we included a wide range of patients from 20 to 87 years old, and did not consider bone union time and rate according to age. Finally, to illustrate the superiority of intramedullary nailing, it must be compared with other surgical techniques.
Radiologic union and good clinical outcome were obtained in all cases in this study, regardless of fracture type. In cases of the complex type, although it took more time than radiological union, there were no differences in the clinical results compared to the simple and wedge type unions. Intramedullary nailing using the Polarus humeral nail is considered to be a good treatment modality for all types of humeral shaft fractures, especially for the treatment of complex types of injuries, such as segmental or comminuted humeral shaft fractures.
IRB approval: Daegu Catholic University College of Medicine (No. CR-18-128-L).
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Simple radiographs of type A fracture. Preoperative (A) and 4 months of follow-up (B) anteroposterior radiographs. (C) Lateral radiograph at the 4 months of follow-up.
Simple radiographs of type B fracture. Preoperative (A) and 5 months of follow-up (B) anteroposterior radiographs. (C) Lateral radiograph at the 5 months of follow-up.
Simple radiographs of type C fracture. Preoperative (A) and 1 year of followup (B) anteroposterior radiographs. (C) Lateral radiograph at the 1 year of follow-up.
Patients’ Demographics
Variable | Group I (n=15) |
Group II (n=15) |
---|---|---|
Mean age at the time of surgery (yr) | 63.7 | 62.5 |
Sex (male/female) | 4/11 | 8/7 |
Injured side (right/left) | 6/9 | 7/8 |
Injury mechanism (t/s/f/c) | 9/5/0/1 | 3/9/2/1 |
Fracture type (A/B/C) |
12/3/0 | 0/0/15 |
Mean follow-up period (yr) | 2.0 | 2.7 |
Values are presented as mean or number only.
t: traffic accident, s: simple slip, f: simple fall, c: contusion after lower energy trauma.
Types were based on the Orthopaedic Trauma Association (OTA)/Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification system, and the 3 main fracture types were divided into simple (type A), wedge (type B), and complex fractures (type C).
Group I: type A and B, Group II: type C according to the AO/OTA fracture classification system.
Comparison of Radiographic and Clinical Outcome between Group I and II
Variable | Group I (n=15) |
Group II (n=15) |
|
---|---|---|---|
Radiological union (mo) | 5.0 ± 1.41 | 8.4 ± 1.81 | <0.01 |
Clinical union (mo) | 1.6 ± 0.66 | 2.0 ± 0.61 | 0.441 |
KSS | 89.7 ± 6.01 | 90.6 ± 5.72 | 0.352 |
Operation time (min) | 83.6 ± 10.21 | 101.6 ± 10.52 | <0.01 |
Postoperative VAS | 0.6 ± 0.12 | 0.8 ± 0.25 | 0.493 |
Values are presented as mean ± standard deviation.
KSS: Korean shoulder scoring system, VAS: visual analogue scale.
Group I was type A (simple) and B (wedge), Group II was type C (complex fractures); each types were based on the Orthopaedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen fracture classification system.