Combined Medial and Lateral Approach Versus Paratricipital Approach in Open Reduction and Internal Fixation for Type C Distal Humerus Fracture: A Randomized Controlled Study

Abstract

Objective

Olecranon osteotomy and paratricipital approaches were widely used in the treatment of type C distal humerus fracture but some disadvantages exist, so a combined medial and lateral approach was designed. The objective of this study was to investigate and compare the clinical outcomes of combined medial and lateral approach with the paratricipital approach in open reduction and internal fixation of type C distal humerus fractures.

Methods

From May 2018 to April 2020, 37 patients with type C distal humerus fracture who accepted open reduction and internal fixation in our hospital were enrolled in this study. All cases were randomly divided into two groups according to the surgical approach: combined medial and lateral approach group (19 cases), paratricipital approach group (18 cases). All of the patients received open reduction and double vertical plates fixation. The operation and follow‐up indexes, including operation time, blood loss, incision length, triceps muscle strength, flexion‐extension arc of elbow and forearm rotation arc, were recorded and compared. Caja score was used to assess the quality of fractures reduction. Mayo Elbow Performance Score (MEPS) was used to evaluate the elbow function in the follow‐up. Complications such as incision infection, ulnar nerve injury, degenerative osteoarthritis, and heterotopic ossification were analyzed.

Results

The differences in age, gender, and AO classification of fractures between two groups were not statistically significant (p > 0.05). The sum of medial and lateral incision length of combined approach group was longer than the midline incision of paratricipital approach group (15.4 ± 0.8 vs. 14.6 ± 0.8, p < 0.05), but there was no significant difference in operation time (103.5 ± 10.2 vs. 106.0 ± 8.8, p > 0.05), blood loss (71.3 ± 24.5 vs. 72.8 ± 24.6, p > 0.05), and Caja score (16.05 ± 5.67 vs. 15.56 ± 5.66, p > 0.05). During the follow‐up, the MEPS of combined approach group was higher than that of paratricipital approach group at 3 months postoperatively (80.5 ± 5.7 vs. 68.9 ± 8.1, p < 0.05), but there was no significant difference in MEPS at 6 months postoperatively (83.9 ± 6.6 vs. 79.7 ± 7.0, p > 0.05) and at the last follow‐up (86.8 ± 7.1 vs. 86.9 ± 7.7, p > 0.05) between the two groups. There was no significant difference in triceps muscle strength (p > 0.05), flexion‐extension arc (126.8 ± 5.3 vs. 128.9 ± 6.0, p > 0.05), and forearm rotation arc (163.2 ± 5.3 vs. 163.6 ± 4.8, p > 0.05) at the last follow‐up. Although the incidence of complication of combined approach group (15.8%) was lower than that of paratricipital approach group (22.2%), the difference was not statistically significant (p > 0.05).

Conclusions

The combined medial and lateral approach was an effective and safe way of open reduction and internal fixation for type C distal humerus fractures. Compared with the paratricipital approach, the combined medial and lateral approach could restore the elbow function more quickly postoperatively, and the long‐term results were comparable.

Experiences of 37 patients with type C distal humerus fracture who received open reduction and internal fixation with combined medial and lateral approach and paratricipital approach were present in this article. Compared with the paratricipital approach, the combined medial and lateral approach could restore the elbow function more quickly postoperatively, and the long‐term results was comparable.

Introduction

Distal humerus fractures involve the supracondylar region and articular surface of distal humerus, which are relatively uncommon in adults and account for approximately 2%–6% of all humeral fractures and 30% of all elbow fractures. ¹ , ² , ³ These fractures frequently occur in a bimodal distribution: low‐energy trauma among the elderly and the patients with osteoporosis, high‐energy trauma in young patients. ⁴ The majority of these fractures were intra‐articular and required anatomic reduction of the articular surface and rigid fixation in order to tolerate earlier postoperative rehabilitation. ⁴ Only patients who have entirely undisplaced fractures, those who suffer with severe comorbidity, and those unable to tolerate surgical anesthesia risks were candidates for nonoperative treatment of distal humerus fractures. ³ Except for the circumstances listed above, all distal intra‐articular humerus fractures should be managed with surgical treatment to regain a painless, stable, and mobile elbow.

According to Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association (AO/OTA) classification, type C distal humerus fracture is the most complicated form of intra‐articular fracture in which the articular surface is completely dissociated from the shaft of the humerus. The AO/OTA system further subclassifies type C distal humerus fractures into simple (C1), simple articular with metaphyseal multi‐fragmentation (C2), and multi‐fragmentation of the articular surface and metaphyseal zone (C3). ⁵ Open reduction and internal fixation with double plates either vertical or parallel was the most common treatment for type C distal humerus fractures, which was a great challenge for even the most experienced orthopaedic surgeons because of the comminuted fractures and the complexity of anatomical features. An appropriate approach should not only fully expose the fragments and achieve anatomical reduction of the articular surface, but also preserve the soft tissue around the fractures as much as possible and avoid important vascular and nerve injury. Many approaches were designed to treat the AO type C distal humerus fractures, including the paratricipital, the triceps‐reflecting anconeus pedicle (TRAP), the triceps‐reflecting, the olecranon osteotomy, and the triceps‐splitting. ⁶ , ⁷ , ⁸ , ⁹ , ¹⁰ , ¹¹ , ¹² , ¹³

There were still some controversies on this issue. Olecranon osteotomy had been the golden standard approach for intra‐articular distal humerus fractures in the past. ¹⁰ , ¹⁴ This approach could provide sufficient visibility of the majority articular surface except the anterior part and adequate operation space for accurate reduction and fixation of articular surface fragments. ¹⁵ However, relevant complications have restricted its wider adoption such as loss of osteotomy reduction, nonunion, implant irritation, and artificial osteotomy fractures were not conducive to earlier functional exercise postoperatively. ¹⁰ Therefore, the surgical approach that preserves the integrity of the elbow extensor device has been developed. Some scholars believe that a paratricipital approach was sufficient to meet the requirements of the surgical field without an olecranon osteotomy for type C distal humerus fractures. ¹⁶ , ¹⁷ The paratricipital approach was particularly suitable for extra‐articular and intra‐articular distal humerus fractures which were not complicated (C1 and C2 fractures) since it could preserve triceps continuity and the attachment to olecranon. However, the main disadvantage of this approach was the limited exposure of the anterior articular surface. In recent years, a combined medial and lateral approach was designed to treat type C distal humerus fractures. As far as we know, there was only one published study reporting the use of a combined medial and lateral approach for intra‐articular distal humerus fracture. ¹⁸

The aims of this study were to: (i) evaluate the clinical outcomes of the combined medial and lateral approach for type C distal humerus fractures; (ii) analyze the complications of the combined medial and lateral approach; (iii) compare the clinical outcomes and safety of the combined medial and lateral approach with the paratricipital approach for type C distal humerus fractures.

Methods

Inclusion Criteria

1. Patients diagnosed with AO type C distal humerus fractures, ⁵ older than 18 years;

2. Planning to receive the treatment of open reduction and internal fixation;

3. Followed up regularly as required, at least with complete follow‐up for 12 months.

Exclusion Criteria

1. Patients accompanied with serious comorbidity who cannot tolerate anesthesia or choose conservative treatment;

2. Open fractures;

3. Patients with preoperative nerve and vascular injury;

4. Cases of incomplete clinical or follow‐up data;

5. Accompanied with rheumatoid arthritis, osteoarthritis, and other degenerative diseases of the elbow joint which would influence the postoperative elbow function.

This study was a randomized controlled trial which had been approved by the ethics committee of West China Airport Hospital (2018‐KS‐02). The clinical trial registration number was ChiCTR2200066248. All patients signed the informed consent for clinical trials after admission. From May 2018 to April 2020, 37 patients with type C distal humerus fractures who met the inclusion and exclusion criteria were enrolled in this clinical trial. All patients were requested to be followed up for at least 12 months. A random number table was used to determine which patients should be allocated to the groups, as follows: (i) combined medial and lateral approach group, 19 cases; (ii) paratricipital approach group, 18 cases. There were 16 males and 21 females aged from 27 to 76 years old. There was no significant difference in age, gender, AO classification of fractures between the two groups (p > 0.05, Table 1).

TABLE 1.

Demographics of patients with AO type C distal humerus fractures

Group	Cases	Age	Gender		AO Classification
	(n)	(years)	Male	Female	C1	C2	C3
Combined approach group	19	46.5 ± 12.3	9	10	5	9	5
Paratricipital approach group	18	48.0 ± 12.7	7	11	4	11	3
p		0.722 (t = −0.359)	0.743		0.75

Preoperative Treatment

Temporary elbow immobilization and elevation of the affected limb to eliminate swelling were taken after admission. Carefully examine the skin to make sure there were no open wounds which are most commonly posterior when present, assess the ipsilateral shoulder and wrist, and check the nerve and vascular function. The radial, ulnar, and medial nerves should be checked in a neurological examination. Routine X‐ray films and a computer tomography scan with sagittal and coronal plane reconstruction were also necessary to assess the fracture morphology and make a surgical plan.

Surgical Procedures of the Combined Medial and Lateral Approach

All patients were treated in a lateral decubitus position under general anesthesia. A pneumatic tourniquet was placed as proximally as possible on the upper arm. The lateral incision was approximately 9 cm proximal to the lateral humerus condyle. After dissection of the lateral condyle origin of the wrist extensors and lateral ligamentous complex, the lateral elbow capsule was exposed. The most distal articular surface of the capitulum and the lateral part of the trochlea were exposed by moving the biceps and brachialis anteriorly and the triceps posteriorly. Then the medial incision approximately 7 cm was made proximal to the medial condyle. The ulnar nerve was carefully released from the ulnar nerve groove and protected. The medial and anteromedial part of the distal humerus was exposed through the approach between the brachialis and medial intermuscular septum. The trochlea was visible after the anterior capsule was incised.

All hematoma among the fragments was debrided. The first step of reduction was restoring the intercondylar articular fractures under direct visualization or fluoroscopy guidance. Comminuted and unstable fragments could be taken out of the body for temporary reduction and fixation with small‐diameter (0.8, 1.0 mm) Kirschner wires, and then put back. Any articular step or gap should be abolished by manual reduction and compression with forceps. A cannulated screw, inserted between two relatively large articular fragments in a manner which allows adequate space for later plate application, was used to restore the integrity of the articular surface. The articular fragments usually associated with the metaphyseal were reduced and fixed to medial and lateral column with Kirschner wires temporarily. The reduction of the articular fragments was checked under direct visualization or fluoroscopy guidance. Two vertical double plates (Trauson Jiangsu Medical Equipment Company, China) were used to definitively fix from lateral to medial side, with at least four screws in the articular fragments. ¹⁹ Fracture fixation stability and elbow range of motion were assessed. Lateral collateral ligamentous complex should be repaired with drill‐holes and a locking suture technique to prevent posterolateral rotatory instability in all cases. Anterior transposition of the ulnar nerve was routinely carried out before the incisions closed. Subcutaneous drainage tube was placed and the incision was closed layer by layer.

Surgical Procedures of the Paratricipital Approach

All patients were treated in a lateral decubitus position under general anesthesia. A pneumatic tourniquet was applied on the upper arm to decrease blood loss and clear the surgical aera. A posterior longitudinal incision of ~14–16 cm was made, curving laterally around the olecranon and extending distally about 5 cm from the olecranon to the forearm. Full‐thickness subcutaneous flaps overlying the triceps were dissected and elevated. The ulnar nerve was identified and protected when the medial subcutaneous flap was dissected. The medial and lateral borders of the triceps muscle were identified and separated from the intermuscular septum respectively to form the medial and lateral windows. The triceps was separated from the posterior part of the distal humerus by blunt dissection and “two windows” were connected. A piece of gauze was used to manipulate two moving surgical windows to improve the visibility of articular surface fragments.

The distal humerus articular fragments were anatomically reduced posteriorly under direct visualization or indirectly under fluoroscopy guidance. In this approach, although anterior articular surface was not clearly visible, if distal and posterior articular fragments were reduced anatomically, the anterior articular surface was automatically reduced as well. The articular fragments were fixed with a cannulated screw. Then the distal fragment was anatomically reduced with medial and lateral column and temporarily fixed with Kirschner wires under direct visualization through both medial and lateral windows. Definitive fixation with two vertical plates (Trauson Jiangsu Medical Equipment Company, China) and at least four screws implanted in the articular fragments was carried out. The fracture fixation stability and elbow range of motion were assessed. The anterior transposition of the ulnar nerve was routinely performed. A subcutaneous drainage tube was placed and the incision was closed.

Postoperative Treatment

Intravenous antibiotics were administered within 24 h postoperative to prevent wound infection. The drainage tube was removed 24 h postoperatively. Indomethacin was given orally for heterotopic ossification prophylaxis for 4 weeks. Elbow flexion‐extension exercise can be carried out the next day after operation; however, the exercise should temporarily stop if symptoms of incision inflammation appear. The patients were followed up at 1, 2, 3, 6, and 12 months postoperatively and then every half a year after that, and accepted rehabilitation exercise with the doctor's guidance.

Follow‐Up

Clinical Results

Some intraoperative indexes were recorded and compared, including operation time, blood loss, incision length. The operation time was calculated as from the skin incision to skin closure. The intraoperative blood loss was measured by calculation method. The incision length was measured with rulers. The flexion‐extension arc of elbow and forearm rotation arc were measured with goniometric measurement.

Caja Score

The Caja scoring system was used to evaluate the quality of surgical reduction of distal humerus fractures. ²⁰ The following six criteria were assessed in immediate postoperative radiographs: (i) Articular cartilage step: less than 1 mm; (ii) Articular surface diastasis: less than 1 mm; (iii) AP carrying angle (15° valgus): mal‐alignment less than 10°; (iv) Lateral trochlea and capitellum angle (40°): Mal‐alignment less than 10°; (v) Articular space reduction: less than 1 mm; (vi) Para‐articular calcifications: less than 10 mm. These reduction parameters were measured on standard immediate postoperative anteroposterior elbow radiographs using Silver PACS software (developed by Beijing Silver Medical Information Technical Co. Ltd). The maximum score was 20 points, with a reduction of 5 points for each criterion not met and 0 points for pseudoarthrosis.

Triceps Muscle Strength

The triceps muscle strength was evaluated manually by the surgeon using contralateral triceps as a reference and graded as normal, good, and fair. ²¹ The patient was put in a prone position on the examination table with the arm in 90° abduction, the elbow in 90° flexion, and the forearm in neutral rotation. With one hand of the surgeon supporting the patient's arm just above the elbow and the other hand applying resistance on the dorsal surface of the patient's forearm, the patient was asked to extend the elbow against resistance. ¹⁶

Mayo Elbow Performance Score (MEPS)

MEPS was widely used to evaluate the function of elbow. ²² The scoring system consists of pain, motion, stability, and elbow function. The aggregate score was 100, including 45 points for pain, 20 points for exercise, 10 points for stability, and 25 points for junction function. A score greater than 90 was classified as excellent, 75–89 as good, 60–74 as fair, and less than 60 as poor.

Complications

Complications such as incision infection, ulnar nerve injury, degenerative osteoarthritis, and heterotopic ossification were compared between the two groups.

Statistical Analysis

The measurement data was expressed as mean ± standard deviation. SPSS 24.0 (IBM corporation, USA) was used to analyze the data. Unpaired t test was used to compare age, operation time, blood loss, incision length, Caja score, MEPS, the flexion‐extension arc of elbow, and forearm rotation arc. Count data including gender, fracture classification, triceps muscle strength, and complications were compared by Fisher's exact probability. The statistical significance level was set at p < 0.05.

Results

Fracture Union

All patients were followed up for an average of 14.6 months (range, 12 to 18 months) as a result. Fracture union was defined as the absence of pain and obscurity of the fracture line between fragments in the metaphyseal region. All the fractures healed and the average time of fracture union was 3.2 months (range, 2 to 5 months).

Operation Indexes

The operation time was 103.5 ± 10.2 min and 106.0 ± 8.8 min in combined approach group and paratricipital approach group, respectively, and the blood loss was 71.3 ± 24.5 mL and 72.8 ± 24.6 mL in combined approach group and paratricipital approach group, respectively. There was no significant difference in the operation time and blood loss between the two groups (p > 0.05, Table 2). The incision length of combined approach group (15.4 ± 0.8 cm) was longer than that of paratricipital approach group (14.6 ± 0.8 cm) (p < 0.05, Table 2).

TABLE 2.

Clinical result between combined approach group and paratricipital group

Group	Cases (n)	Operation time (min)	Blood loss (mL)	Incision length (cm)	Caja score	MEPS 3 m postop	MEPS 6 m postop	MEPS at the last follow up	flexion‐extension arc	forearm rotatio arc
combined approach group	19	103.5 ± 10.2	71.3 ± 24.5	15.4 ± 0.8	16.05 ± 5.67	80.5 ± 5.7	83.9 ± 6.6	86.8 ± 7.1	126.8 ± 5.3	163.2 ± 5.3
paratricipital approach group	18	106.0 ± 8.8	72.8 ± 24.6	14.6 ± 0.8	15.56 ± 5.66	68.9 ± 8.1	79.7 ± 7.0	86.9 ± 7.7	128.9 ± 6.0	163.6 ± 4.8
t		−0.803	−0.181	2.859	0.267	5.043	1.898	−0.042	−1.091	−0.272
p		0.428	0.857	0.007	0.791	0.000	0.066	0.967	0.283	0.788

Elbow Flexion‐Extension and Forearm Rotation Arc

At the last follow‐up, the flexion‐extension arc of the elbow was 126.8 ± 5.3° vs. 128.9 ± 6.0°, the forearm rotation arc was 163.2 ± 5.3° vs. 163.6 ± 4.8° in combined approach group and paratricipital approach group, respectively, and there was no significant difference between the two groups (p > 0.05).

Caja Score

The Caja scores were 16.05 ± 5.67 and 15.56 ± 5.66 in combined approach group and paratricipital approach group, respectively. There was no significant difference in the quality of surgical reduction between the two approaches (p > 0.05).

Triceps Muscle Strength

A total of 16 patients were classified as normal and three patients were classified as good in combined approach group, while 14 patients were classified as normal and four patients were classified as good in paratricipital approach group. There was no statistical difference of triceps muscle strength at the last follow‐up between the two groups (p > 0.05).

MEPS

The MEPS of combined approach group was higher than that of paratricipital approach group at 3 months postoperatively (80.5 ± 5.7 vs. 68.9 ± 8.1, p < 0.05), but there was no significant difference between the two groups at 6 months postoperatively (83.9 ± 6.6 vs. 79.7 ± 7.0, p > 0.05) and at the last follow‐up (86.8 ± 7.1 vs. 86.9 ± 7.7, p > 0.05). Details in Table 2.

Intraoperative images of the combined medial and lateral approach were present in Figure 1, and representative cases of two approaches in Figures 2, 3, 4.

FIGURE 1.

Intraoperative images of the combined medial and lateral approach. (A) The lateral incision. (B) The medial incision. (C) The lateral ligamentous complex was dissected from the lateral epicondyle of the humerus. (D) The ulnar nerve was dissected and protected in a medial approach. (E) The lateral column of the distal humerus was reduced and fixed with an anatomical locking plate. (F) Fixation of the medial column with an anatomical locking plate

FIGURE 2.

A 44‐year‐old female patient with type C3 distal humerus fracture was treated with a combined medial and lateral approach. (A) Preoperative anteroposterior and lateral films of the elbow. (B) Preoperative CT three‐dimensional reconstruction films. (C) Anteroposterior and lateral X‐ray films immediately after fixation with double plates. (D) Anteroposterior and lateral X‐ray films at 12 months postoperative. (E) Anteroposterior and lateral X‐ray films at 18 months postoperative showed the fracture had healed. (F) The posterior lateral and medial incision scars. (G) The flexion and extension of the left elbow was partly limited at 18 months postoperative. (H) The pronation‐supination of the left forearm was normal at 18 months postoperative

FIGURE 3.

A 39‐year‐old male patient with left distal humerus fracture was treated through a combined medial and lateral approach. (A) Preoperative X‐ray films of distal humerus fracture. (B) Anteroposterior and lateral X‐ray films immediately after operation. (C) Anteroposterior and lateral X‐ray films at 2 months after operation. (D) Anteroposterior and lateral X‐ray films at 12 months postoperative. (E) Anteroposterior and lateral X‐ray films at 18 months postoperative showed the fracture had healed. (F) The image of medial and lateral incision scars. (G) The flexion and extension of the left elbow at 18 months postoperative. (H) The pronation‐supination of the left forearm at 18 months postoperative

FIGURE 4.

A 32‐year‐old male patient with type C distal humerus fracture was treated with a paratricipital approach. (A) Preoperative anteroposterior and lateral films of the elbow. (B) Preoperative CT three‐dimensional reconstruction films. (C) Anteroposterior and lateral X‐ray films immediately after fixation with double plates. (D) Anteroposterior and lateral X‐ray films at 3 months postoperative. (E) Anteroposterior and lateral X‐ray films at 1 year postoperative showed the fracture had healed. (F) The posterior midline incision scar. (G) The flexion and extension of the left elbow at 1 year postoperative. (H) The pronation‐supination of the forearm at 1 year postoperative

Complications

No complication of internal fixation failure, intraoperative injury of blood vessels and fracture nonunion occurred. One superficial incision infection had recovered after exchanging incision dressing for 4 weeks and one patient who suffered from iatrogenic ulnar nerve injury had spontaneously recovered 3 months later in paratricipital approach group. There were two cases of degenerative osteoarthritis in combined approach group and one in paratricipital approach group. One case of heterotopic ossification was present in both groups, respectively. As a whole, although the incidence of complication of combined approach group (15.8%) was lower than that of paratricipital approach group (22.2%), the difference was not statistically significant (p > 0.05).

Discussion

Two different surgical approaches for type C distal humerus fractures were investigated and compared in this randomized controlled clinical study. We found that the combined medial and lateral approach was an effective and safe approach with better early clinical functional outcomes than the paratricipital approach. However, there was no significant difference in the last follow‐up clinical outcomes and postoperative complications. We can choose a reasonable surgical approach for type C distal humerus fractures depending on the fracture pattern and displacement of the articular fragments.

Distal Humerus Fracture Approaches

Various approaches working through or around the triceps muscle in a posterior midline incision were described in the past few years. Olecranon osteotomy was considered as the golden standard for the open reduction and internal fixation of distal humeral intra‐articular fractures due to adequate exposure of articular surface. ²³ Wilkinson reported that the exposure of the articular surface for the triceps‐splitting, triceps‐reflecting, and olecranon osteotomy approaches in cadaver models were 35%, 46%, and 57%, respectively. ¹⁵ In recent years many studies have reported that the olecranon osteotomy approach does not seem to have a clinical advantage over the approaches that preserve the integrity of the elbow extensor device. ¹⁶ , ²³ , ²⁴ , ²⁵ Jacko compared 18 patients with type C distal humerus fractures who underwent paratricipital approach with 22 patients who underwent olecranon osteotomy approach and found that there was no significant difference in the functional outcomes. ²⁴ A retrospective comparison to exposure type C distal humerus fractures showed that triceps‐sparing was better than olecranon osteotomy for C1 and C2 fractures, and even for the most complex C3 fractures, the results were similar. ²⁵ The olecranon osteotomy approach has many potential complications such as longer operation time, delayed union and nonunion of olecranon, prominent hardware, secondary procedures to remove implants, possible restrictions for postoperative mobilization and physiotherapy.

The olecranon osteotomy, which should cut off the elbow extensor device, has many possible complications; therefore, the approaches of preserving the integrity of extensor devices have been paid more and more attention. In 1972, Alonso‐Llames first proposed the paratricipital approach for supracondylar humerus fractures, which could provide full exposure and preserve the integrity of triceps. ²⁶ The paratricipital approach could provide adequate exposure with no adverse effect on triceps muscle strength and allow early initiation of elbow motion by a paratricipital “two‐window” approach. ¹⁶ However, the exposure of intercondylar fracture is insufficient and it is difficult to reduce and fix the anterior articular surface fragments for complex C3 fractures. ¹⁶ Type C distal humerus fractures caused by high‐energy trauma were usually accompanied with severe soft tissue swelling even tension blisters. Significant tension was often present around the midline incision postoperatively. To solve these problems, a combined medial and lateral approach was used to treat these fractures. As far as we know, there was only one published study which reported the combined medial and lateral approach for open reduction and bi‐columnar internal fixation of intra‐articular distal humerus fractures. ¹⁸ Xie et al. retrospectively analyzed 19 cases of intra‐articular fractures, who were treated with open reduction and double‐column fixation using a combined medial and lateral approach, with an average follow‐up of 15.8 months. All fractures healed. The average MEPS reached 93.7 points, 13 were excellent, and six were good. They concluded that intra‐articular fractures of the distal humerus can be effectively treated by open reduction and internal fixation through a combined medial and lateral approach. ¹⁸ Wei reported an anatomical study of the combined medial and lateral approach for distal humerus fractures. ²⁷ Twelve fresh frozen adult cadaveric elbows were randomly divided into two groups: medial‐lateral group and olecranon osteotomy group. The combined medial‐lateral approach exposed 46.9% of the whole distal humeral articular surface, while the olecranon osteotomy approach exposed 63.1%, with statistically significant difference. They concluded that the combined medial‐lateral approach could be recommended to treat intra‐articular fractures with a simple pattern in the posterior with the anterior side of the distal humerus less comminuted. ²⁷

Clinical Effect of Combined Medial and Lateral Approach

In this clinical study, the mean MEPS was 86.8 points in combined medial and lateral approach group, with 10 excellent, seven good, and two fair. The result of Xie's report ¹⁸ that the average MEPS was 93.7 points, 13 excellent, and six good were better than our study, which would be due to the smaller number of C3 fractures in this study. The MEPS of the combined medial and lateral approach was better than the paratricipital approach at 3 months postoperatively. There was no significant difference of Caja score in immediately postoperative radiographs, MEPS, and range of motion of the elbow in a long‐term follow‐up.

The largest advantage of the combined medial and lateral approach is maintaining the integrity of elbow extensor devices and triceps muscle strength. Sixteen patients (84.2%) were normal and three patients (15.8%) had good triceps muscle strength in the combined approach group in this study, which was consistent with the outcome that 21 patients (84%) were normal and four patients (16%) had good triceps muscle strength in the existing literature. ¹⁶ Neither the paratricipital approach in the literature nor the combined approach in this study damaged the continuity and the normal conduction of the triceps.

The anterior articular surface of distal humerus could be fully exposed by dissection of the lateral condyle insertion of the wrist extensors and lateral ligamentous complex, the combined approach is more suitable for not only type C1, C2 but also some C3 distal humerus fractures. Early postoperative range of motion exercise was very essential for recovery of the normal function of the elbow, ²⁸ , ²⁹ the combined approach could meet the need of early postoperative range of motion exercises for the higher MEPS at 3 months postoperatively in this trial. Theoretically, the incision length in combined approach can be reasonably designed according to the fracture pattern and displacement. Shortening the incision of the simple fracture side was possible despite the statistics showing that the incision length of the combined approach was longer than the paratricipital approach. Furthermore, it is also a good choice for some special patients, such as obesity and poor skin conditions in the posterior elbow.

On the other hand, the disadvantage of this approach is intraoperative conversion to total elbow arthroplasty could be challenging. The posterior articular surface of the distal humerus in this approach is still not as fully exposed as the olecranon osteotomy approach for some severe comminuted C3 fractures.

Complication

The complication rate for intra‐articular distal humerus fractures ranged from 29% to 53% in the published literature review. ²⁹ , ³⁰ , ³¹ Postoperative complications of type C distal humerus fractures are not uncommon, such as incision infection, ulnar nerve injury, degenerative osteoarthritis, heterotopic ossification, and elbow stiffness. ³ Although there was insufficient evidence for or against transposition of ulnar nerve, anterior transposition was performed in all cases and no ulnar nerve injury occurred in the combined approach group. A meta‐analysis of 1829 cases with type C distal humerus fracture reported the complication of postoperative osteoarthritis occurred in 142 cases (7.8%). ³¹ The incidence of postoperative osteoarthritis (8.1%) in our study are similar to this report. Two cases of degenerative osteoarthritis in the combined approach group were C3 fractures, the Caja score was 0 and 5 points, respectively. The occurrence of degenerative osteoarthritis was associated with poor reduction, which emphasized the importance of anatomic reduction of the articular surface in reducing the risk of degenerative osteoarthritis. The incidence of complications of the combined medial and lateral approach (15.8%) was lower than that of the paratricipital approach (22.2%), but the difference was not statistically significant. The combined medial and lateral approach is a relatively safe way which does not increase postoperative complications.

Strengths and Limitations of this Study

This study demonstrated a novel combined medial and lateral approach for type C distal humerus fracture, which is a prospective randomized controlled trial with a relatively high level of evidence and strong persuasive conclusions. Given this approach is an innovative approach and rarely reported, this study provides important reference value for open reduction and internal fixation of these fractures. However, there were some limitations in this study. The evaluation criteria of the quality of surgical reduction were measured on X‐ray radiographs, which would be more accurate in computed tomography. The exact exposure range of two surgical approaches on cadaveric specimens have not been compared due to limited conditions. The follow‐up was relatively short, and the number of samples was small, so large multicenter samples and long‐term follow‐up trials were need to confirm the clinical outcomes in the future.

Conclusion

Type C distal humerus fractures can be effectively and safely treated by a combined medial and lateral approach. This approach enables adequate exposure and fixation of C1, C2, and some C3 distal humerus fractures with a low incidence of complications. Compared with the paratricipital approach, the combined medial and lateral approach could restore the elbow function more quickly postoperatively, and the long‐term results were comparable. For some severe comminuted C3 fractures, however, the posterior articular surface of the distal humerus in combined approach is still not as fully exposed as the olecranon osteotomy approach.

Author Contributions

Lin Teng and Gang Zhong designed this research. Lin Teng, Hai‐bo Li, and Shi‐qiang Cen performed the research. Liang Li and Da‐hai Liu collected and analyzed the data. Lin Teng and Gang Zhong wrote this manuscript. There is no funding for this study.

Conflict of Interest

All authors declare that they have no conflict of interest.

Ethics Statement

This study was approved by the ethics committee of West China Airport Hospital (2018‐KS‐02). Informed consent was obtained from all the patients.