A comparative study of locking plate combined with minimally invasive plate osteosynthesis and intramedullary nail fixation in the treatment of Neer classification of 2-part and 3-part fractures of the proximal humerus

DOI: https://doi.org/10.21203/rs.3.rs-2491279/v1

Abstract

Objective:To compare the clinical efficacy of minimally invasive locking plate technique (Philos plate) and interlocking intramedullary nailing technique (TRIGEN intramedullary nail) in the treatment of Neer two-part and three-part proximal humeral fractures.

Methods and materials:The clinical data of 60 patients with Neer two-part and three-part proximal humerus fractures admitted to Hospital from April 2017 to April 2020 were retrospectively analyzed. 32 cases were treated with minimally invasive locking plate technique (minimally invasive plate group) and 28 cases were treated with interlocking intramedullary nailing technique (intramedullary nail group). The operation time, intraoperative blood loss, incision length, fracture healing time, and postoperative complications were compared between the two groups. ASES score and Constant-Murley score were used to evaluate the shoulder joint function of the two groups one year after surgery.

Results:All 60 patients were followed up for 12 to 24 months, with an average of 16 months. There was no significant difference in operation time, intraoperative blood loss, incision length and fracture healing time between the two groups (P>0.05). The incidence of postoperative complications in the intramedullary nail group was significantly lower than that in the minimally invasive steel plate group, and the difference between the groups was statistically significant (P<0.05). There was no significant difference in ASES score and Constant-Murley score between the two groups one year after surgery (P>0.05).

Conclusion:The use of minimally invasive locking plate technique and interlocking intramedullary nailing technique in the treatment of Neer two-part and three-part proximal humerus fractures has the advantages of small incision, less blood loss, and high fracture healing rate, and both can achieve satisfactory clinical effects. The internal nail technique is more convenient than the minimally invasive locking plate technique in controlling postoperative complications.

Introduction

Proximal humerus fractures occur in 5–6% of all fractures in the human body1. With the acceleration of population aging, this fracture often occurs in elderly patients over 65 years old, accounting for about 68% of all proximal humeral fractures, and ranks fourth in the incidence of fractures in elderly patients after vertebral compression fractures, distal radius fractures, and hip fractures2. Most proximal humeral fractures are unstable fractures, and conservative treatment requires long-term braking, which is prone to shoulder stiffness and activity limitation, progressive traumatic arthritis, humeral head necrosis and other complications, which greatly affect the recovery of shoulder joint function of patients3. The classification of proximal humerus fractures commonly used is Neer classification based on the number of fracture blocks and the degree of displacement, which is of great significance for the evaluation of prognosis4. Among them, the most common classification is Neer classification of two-part and three-part fractures. Operation of proximal humeral fractures are usually from the pectoralis major, deltoid muscle between the groove cut into the road, reset, steel plate internal fixation treatment, this approach has the advantage of operative field exposure, under the direct reduction, slab, easy to operate, but the surgical trauma, take extensive dissection soft tissue, haemorrhage is much, does not apply to merge more than basic diseases, poor surgery tolerance of patients with fracture of proximal humerus elderly. In recent years, with the popularization of minimally invasive concept, the improvement of surgical techniques, and the development of new orthopedic instruments, clinical orthopedic surgeons are more and more inclined to use percutaneous minimally invasive technique for the treatment of Neer type two-part and three-part fractures of proximal humerus. The commonly used minimally invasive techniques include minimally invasive locking plate technique and intramedullary nail technique. The clinical efficacy comparison of these two minimally invasive techniques is still controversial at present.

Thus, the purpose of this study was to compare the clinical effects of proximal humeral fractures treated with minimally invasive locking plate technique or interlocking intramedullary nailing technique. operation time, intraoperative blood loss, fracture healing time, incision length, the ASES, Constant-Murley score and postoperative complications were systematically analyzed in the study.

Methods And Materials

Patients

Inclusion and exclusion criteria

The entire cohort of 28 patients treated with interlocking intramedullary nailing (Study group) and 32 patients treated with minimally invasive locking plate (Control group) were retrospectively analyzed in the study at the Changhai Hospital of Navy Military Medical University, Shanghai, between April 2017 and April 2021. Inclusion criteria: Neer classification of two - and three-part closed fractures of proximal humerus. Exclusion criteria: (1) Open proximal humeral fractures; (2) Patients with severe chronic diseases affecting the operation; (3) Neer classification of four-part fractures of proximal humerus; (4) Patients with poor compliance.

Surgical Procedures

proximal humerus plate

Perspective of gram needle positioning to determine and humerus head is central axis line, under the acromion is about 0.5 cm, a longitudinal incision along the anterolateral tag line do, incision length is not more than 5 cm, cut the skin and subcutaneous tissue, blunt separation of deltoid muscle fibers to the periosteum, silk suture incision distal muscle fibers, avoid operation postpone axillary nerve damage down, The deltoid muscle was retracted laterally and laterally to expose the proximal humerus fracture. If the large and small nodules are displaced, the large and small nodules are sutured with 5-gauge sutures for traction reduction of proximal humeral fractures. If the humeral head is not in a good position, one or two 2.0mm Kirschner wires can be inserted into the humeral head to reduce the fracture as a pry bar, and the Kirschner wire can be used for temporary fixation. Note that the position of the Kirschner wire should not affect plate placement. The bone was stripped down the shaft of the humerus and extraperiosteal was dissected to establish an extraperiosteal tunnel. The non-absorbable line suturing nodules of large and small was passed through the suture hole reserved at the proximal edge of the plate. A longitudinal incision about 2cm in length was made at the distal end of the plate, and the Philos plate was placed 5-8mm below the vertex of the greater tubercle. Nodules ditch between the lateral 6–8 mm, before steel distal common hole in one common screw, tighten the screw plate near the bone surface, perspective, confirm fracture plate position is good, the proximal placement 5–6 locking screw, if conditions permit, suggest the proximal screw in two humerus is apart from the screw to reduce fracture shift may, within the distal into two locking screws, Finally, the suture lines of the large and small nodules were tightened and knotted to enhance the stability of the proximal humerus. The incision was closed after fluoroscopy was confirmed again (Fig. 1).

Intramedullary Nail

A longitudinal incision about 3cm in length was made distally from the anterior foot of the acromion. The anterior midsection of the deltoid was bluntly separated, and the deltoid was retracted to the acromial bursa on both sides. The humeral head and nodules were exposed by splitting the acromial bursa longitudinally. If there is displacement of the greater or lesser nodules, the displaced bone mass of the greater or lesser nodules was sutured with a 5-gauge sutures. Proximal humeral fractures can be reduced by manual traction. If the humeral head is in poor position, one to two 2.0mm Kirschner wires can be inserted into the humeral head as a lever to reduce the fracture. If the fracture is unstable after reduction, temporary fixation with a 2.0mm Kirschner wire is used if necessary to ensure that the Kirschner wire does not interfere with intramedullary nail main insertion. Reset and temporary fixed position biceps tendon, after the completion of 6 mm back along the direction of muscle fibers on a cut of the supraspinatus, ca. 2 cm long, incision in humerus head high for into placing needle, needle point C arm fluoroscopy humerus and side, check the fracture and needle position and direction, attention must be in again after the fracture opening, otherwise once the channel is formed, It was extremely difficult to adjust the position. After good confirmation, the intramedullary nails of appropriate length and thickness were inserted by opening drilling, and the fracture reduction was confirmed by fluoroscopy again. Three 4.5mm screws were screwed into the proximal end of the main nail, and two 4.5mm screws were screwed into the distal end of the main nail. To enhance fracture stability, the 5-gauge sutures of the small and large nodules were sutured to the proximal nail hole. Fluoroscopic examination of the internal fixation was performed, the screw length was appropriate, and the incision was sutured layer by layer (Fig. 2).

Evaluation Criteria

The operation time, intraoperative blood loss, fracture healing time and incision length were recorded, and the ASES, Constant-Murley score and postoperative complications were compared between the two groups

Statistical Methods

SPSS 19.0 software was used to analyze the data. The mean ± standard deviation was used to represent the measured data. Independent-sample tests or t-tests were used to compare the two groups. If P < 0.05, the difference was statistically significant.

Results

Patient characteristics

Twenty-eight patients treated with interlocking intramedullary nailing (study group) and thirty-two patients treated with minimally invasive locking plate (control group) were included in our study. The average age was 62.1 ± 2.2 years old in the study group and 61.5 ± 2.6 years old in the control group. 10 patients (35.7%) were male in the study group and 11 patients (34.4%) were male in the control group. Fall down injury was the main cause of injury in the both groups (82.1% vs. 81.3%). All proximal humerus fractures were classified by Neer classifications, and there were 11 patients (39.3%) with 2-part and 17 patients (60.7%) with 3-part in the study group. In the control group, there were 13 patients (40.6%) with 2-part and 19 patients (59.4%) with 3-part. The baseline date of both groups was shown in Table 1, which demonstrated that patients in the distribution of each characteristic were similar in the two groups.

Table 1

The baseline date of the two groups

Characteristics

Control group

Study group

P value

Age (mean, years)

61.5 ± 2.6

62.1 ± 2.2

0.337

Gender

     

Male

11

10

0.914

Female

21

18

 

Cause of injury

     

Traffic injury

5

4

0.986

Fall down injury

26

23

 

High falling injury

1

1

 

Neer classifications

     

Type II

13

11

0.916

Type III

19

17

 

Clinical Outcome Analysis

Clinical outcome analysis

The incision length was 7.4 ± 1.9 cm in the study group and 6.9 ± 2.1 cm in the control group (P = 0.333, Table 2). Blood loss was 61.1 ± 12.6 ml in the study group and 65.5 ± 13.8 ml in the control group (P = 0.198). Operation time was 117.4 ± 28.3 mins in the study group and 124.5 ± 26.7 in the control group (P = 0.321). Fracture healing time was 8.6 ± 2.2 weeks in the study group and 8.9 ± 2.3 weeks in the control group (P = 0.605). The ASES score was 90.5 ± 7.9 in the study group and 89.8 ± 6.4 in the control group (P = 0.709). The Constant-Murley score was 90.7 ± 6.7 in the study group and 91.5 ± 7.7 in the control group (P = 0.666). The complication rates were 7.1% (2/28) in the study group and 28.1% (9/32) in the control group (P = 0.036).

Table 2

The clinical outcome of these two groups

Clinical outcome

Control group

Study group

P value

Incision length

6.9 ± 2.1

7.4 ± 1.9

0.333

Blood loss

65.5 ± 13.8

61.1 ± 12.6

0.198

Operation time

124.5 ± 26.7

117.4 ± 28.3

0.321

Fracture healing time

     

All

8.9 ± 2.3

8.6 ± 2.2

0.605

2-part

8.6 ± 2.1

8.1 ± 2.4

0.395

3-part

9.2 ± 1.9

8.9 ± 2.2

0.575

ASES score

     

All

89.8 ± 6.4

90.5 ± 7.9

0.709

2-part

87.0 ± 10.2

88.2 ± 5.8

0.568

3-part

91.4 ± 9.2

92.7 ± 8.8

0.576

Constant-Murley score

     

All

91.5 ± 7.7

90.7 ± 6.7

0.666

2-part

90.2 ± 7.6

89.3 ± 7.3

0.640

3-part

92.7 ± 6.6

92.2 ± 9.8

0.820

Complications

     

Yes

9

2

0.036

No

23

26

 

Discussion

In this study, we compared the clinical efficacy of minimally invasive locking plate technique and intramedullary nail technique in the treatment of two-part and three-part proximal humeral fractures. It was found that there was no significant difference in intraoperative blood loss, incision length, operation time, fracture healing time, ASES and Constant-Murley score of patients at 1 year after operation between the two groups. The postoperative complication rate of study group was significantly lower than that of control group (7.14% vs 28.12%, P < 0.05). The results revealed that intramedullary nailing is superior to locking plates in controlling the incidence of complications.

Proximal humerus fractures occur mostly in elderly patients, often accompanied by osteoporosis, and belong to intra-articular fractures, which require high reduction requirements and often require surgical treatment. Improper treatment can easily lead to limb disability5. At present, there is still a lot of controversy about how to treat displaced proximal humeral fractures, and there are many types of surgical methods, such as artificial joint replacement6, Pickerner wire fixation7, internal fixation system, etc. In recent years, with the change of treatment concept and the development of new orthopedic instruments8,9, the treatment of proximal humeral fractures is developing towards minimally invasive direction. At present, percutaneous minimally invasive locking plate technique and intramedullary nail technique are most commonly used clinically.

The traditional incision for the treatment of proximal humeral fractures is the deltoid approach, which has the advantages of full exposure and intuitive reduction. However, this approach requires extensive dissection of soft tissue, which is highly traumatic and bleeding, and is not suitable for elderly patients with osteoporosis. In this paper, the author used the lateral deltoid approach, intraoperative just blunt separation of deltoid muscle fibers, without cutting off muscle and affecting postoperative activity of shoulder joint. The intraoperative incision is small and the bleeding is less, which is conducive to the postoperative recovery of the patients. Moreover, we combined with MIPO technology10, percutaneous plate insertion, indirect reduction, protected the blood supply of the broken end of the fracture, and reduced the probability of nonunion and humeral head necrosis. MIPO combined with the new proximal humeral locking plate, the proximal humeral screw is a locking screw, and the multi-angle fixation, compared with the traditional plate, it effectively increases the holding force of the proximal humeral, reduces the incidence of postoperative reduction loss and varus malunion. However, compared with the intramedullary nail, the locking plate belongs to eccentric fixation. From the perspective of biomechanics, its bending resistance and torsion resistance are weaker than those of intramedullary nail, which has been confirmed by relevant biomechanical experiments. Moreover, the proximal incision of this approach is distal to the axillary nerve, and improper operation is likely to cause iatrogenic axillary nerve injury. The results of this study showed that the treatment of proximal humeral fractures with minimally invasive locking plate technique had the advantages of less bleeding, less incision, and better postoperative shoulder joint function, but there were 9 complications (axillary nerve injury in 4 patients, screw removal in 3 patients, and varus malunion in 2 patients).

The early intramedullary nail of the proximal humerus is not a straight nail design, with a 5° valgus Angle, and the opening of the intramedullary nail is outside, which is prone to damage the rotator cuff tissue. Postoperative patients often have symptoms of supraspinatus muscle tendon injury, such as restricted abduction and pain, and the incidence of which is reported in relevant literature to be up to 40%11. The new type of proximal humeral interlocking intramedullary nail has improved the early stage by adopting straight nail design, opening at the highest point of the humeral head and the muscle belly of the supraspinatus muscle, without injury to the rotator cuff, and reducing postoperative complications such as limited pain of the shoulder joint. Compared with plate, intramedullary nail has the biomechanical advantage of central fixation, and the moment arm is smaller than that of eccentric fixation plate, which reduces the possibility of varus displacement after operation. Many previous studies have shown that there is no significant difference in the clinical efficacy of proximal humeral intramedullary nail compared with locking plate, but the postoperative complications of intramedullary nail are lower. Konrad G et al.12 studied the difference in clinical efficacy between intramedullary nail and locking plate in the treatment of three-part proximal humeral fractures. After one year of follow-up, they found that the clinical efficacy of intramedullary nail was similar, but the postoperative complications of intramedullary nail were less than that of locking plate. Von Ruden C et al.13 found that the use of proximal humeral intramedullary nail in the treatment of proximal humeral fractures has the advantages of less trauma, less muscle, soft tissue and periosteal dissection compared with plate, which can enable patients to have early functional exercise, so as to obtain better long-term shoulder joint function. The results of this study showed that there were fewer postoperative complications in the study group compared with the control group, and there were 2 postoperative complications. (1 case had acromion impingement, which was caused by insufficient depth of intramedullary nail insertion; One patient had rotator cuff injury after surgery, which was found to be caused by the deviation of the opening after arthroscopic revision.)

Conclusion

The use of minimally invasive locking plate technique and interlocking intramedullary nailing technique in the treatment of Neer two-part and three-part proximal humerus fractures has the advantages of small incision, less blood loss, and high fracture healing rate, and both can achieve satisfactory clinical effects. The internal nail technique is more convenient than the minimally invasive locking plate technique in controlling postoperative complications.

Declarations

Ethics approval and consent to paticipate

This study was approved by the Medical Research Ethics Board of the Changhai Hospital of Naval Military Medical University, which waived the need for written informed consent due to the retrospective nature of the study. All methods were carried out in accordance with relevant guidelines and regulations.   Research involving human participants, human material, or human data, must have been performed in accordance with the Declaration of Helsinki.

Consent for publication

Not applicable.

Availability of data and materials

The datasets analyzed during the current study are not publicly available due privacy but are available from the corresponding author on reasonable request.

Conflict of interest

The authors declare that they have no conflict of interest.

Funding

The work is supported by the National Science Fund Project (No. 82172431).

Authors' contributions

CD and YZ contributed to the conception and design of this study, the performance of experiments, interpretation, data analysis, and manuscript writing. YL and MZ performed data analysis and interpretation. SN and HT contributed to the design of this study, acquiring financial support, data analysis, interpretation, manuscript writing, and the final approval of the manuscript.

Acknowledgements

The work is supported by the National Science Fund Project (No. 82172431).

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