DOI: https://doi.org/10.21203/rs.3.rs-1310784/v1
Background: Minimally invasive plating has been widely applied to treat long bone shaft fractures. But it was rarely used in clavicle fractures because of the technical difficulties of closed reduction and fixation. We report our improved techniques of minimally invasive treatment for midshaft clavicle fractures using distal clavicle anatomic locking plate and compare its result with that of open reduction and internal fixation.
Materials and methods: A retrospective comparative study was performed in our institution from Jan 2019 to May 2020. Patients with acute midshaft clavicle fractures that were treated with minimally invasive technique or open reduction and internal fixation using distal clavicle anatomic locking plate were included. According to the included and excluded criteria, a total of 58 patients were included and divided into two groups based on the operation technique. We compared the two groups in surgical duration, fracture reduction, time for union, Constant-Murley score, cosmetic result and other complications.
Results: There was no significant difference in quality of reduction between the two groups. The mean surgical duration in minimally invasive group was longer than that in open group (59.5±8.9 min vs. 52.2±7.2 min, P< 0.05). The mean incision length in minimally invasive group was shorter than that in open group (2.1±0.5 cm vs. 11.6±2.0 cm, P< 0.05). In minimally invasive group the mean union time was 3.3±1.1months, no patient complained of paresthesia on subclavicular region, and all patients were satisfied with the cosmesis of the wounds and showed excellent shoulder joint function with a mean Constant-Murley score of 93.8±3.8 at sixth month after the operation. In open reduction group the mean union time was 4.3±0.8months, 8 patients complained of paresthesia on subclavicular region, and only 5 patients were satisfied with the cosmesis of the wounds with a mean Constant-Murley score of 90.6±4.0 at sixth month after the operation. There was a significant difference in statistic by comparing union time, cosmetic result, Constant-Murley score and other complications (P<0.05).
Conclusion: Minimally invasive surgery using distal clavicle anatomic locking plate seems to be a good option for the treatment of midshaft clavicle fractures with satisfactory cosmetic result and excellent return to function.
Clavicle fractures are among the most common fractures in clinical practice. Due to the fairly thin adhesion between the middle and lateral third about 80% of fractures occur in midshaft and half of these fractures will displace[1]. According to Neer’s [2] and Row’s [3] researches, the conservative treatment for midshaft fractures of the clavicle had a lower nonunion rate than open reduction and internal fixation. Historically nonoperative treatment for midshaft clavicle fractures was one of the few golden rules in orthopaedics.
However, some recent studies [4,5,6] showed that operative treatment of midshaft clavicle fractures had a better result than nonoperative treatment in terms of functional recovery, pain relief, clavicle shortening, and pseudarthrosis rate. Therefore operative treatment for midshaft clavicle fractures was usually recommended under some circumstances.
Although, open reduction and plate fixation has been considered as the golden standard in midshaft clavicle fractures treatment, it may lead to large incision and wide soft tissue stripping which destroy the blood supply of fracture site and result in considerable complications, such as poor cosmetic result, nonunion, paresthesia or infection[7]. To overcome these problems, intramedullary nailing has been widely used to treat displaced midshaft clavicle fractures[8,9]. However, migration of the internal fixation and clavicle shortening were common in comminuted fractures and early exercise was restricted due to its weak fixation strength to resist fracture site motion[10]. And it had been confirmed in a recent published prospective randomized controlled trial that plate fixation is the superior method in dealt with comminuted midshaft clavicle fractures [11]. To eliminate these limitations, we designed a minimally invasive percutaneous plating technique for midshaft clavicle fractures treatment using distal clavicle anatomic locking plate[12,13] and improved it in recent years. The purpose of this study is to report our improved minimally invasive techniques and compare its radiographic and clinical outcomes with that of open reduction and internal fixation.
This retrospective comparative study was approved by Medical Research Ethics Committee of our hospital. From Jan 2019 to May 2020, a total of 91 cases were diagnosed as clavicle fractures in our institution. Patients with midshaft clavicle fractures were included and those corresponding to the exclusion criterion were excluded: 1) a patient’s refusal to participate; 2) proximal or distal clavicle fracture; 3) neurovascular injury; 4) open fractures; 5) pathological fractures; 6) fracture seen beyond 2 weeks after the injury; 8).intramedullary nailing fixation. Finally, 58 cases were retrospectively reviewed in this study. According to the surgical technique they were divided into minimally invasive group and open reduction group(Fig.1).
Under general anaesthesia, the patient was placed in a supine position on a radiolucent operating table. For ease of closed reduction muscle relaxant was always required in our cases. A well-padded adequately sized soft bump was placed between the scapulae. To make sure there was no shelter when the C-arm was used, and was tilted in order to obtain inlet and outlet views, if necessary. The involved shoulder and the whole upper extremity were prepared and draped in a sterile fashion so that the whole upper extremity was placed in the operative field. This allowed easier intra-operative manipulation and reduction.
After palpating, the proximal end, distal end and fracture site, a suitable distal clavicle anatomic locking plate was selected and placed along the clavicle. The provisional position of the plate was drawn on the skin under an image intensifier(Fig. 2.c). According to the provisional position of the plate, a 1.0cm-sized oblique incision was performed along the long axial of the clavicle at the center of the distal clavicle end, sharp dissection to the bone and exposing the distal clavicle end. A sub-muscular tunnel along the clavicle was developed with a periosteal elevator and the plate was inserted from the distal incision.
A locking sleeve was placed at the distal end of the plate. The distal plate and segment were fixed in the optimal position with both anterior borders of the plate and distal clavicle end at same horizontal using a K-wire through the locking hole. A tractive force was used through the locking sleeve. After restoration of clavicular length and realignment of the comminuted fragment, we percutaneously fixed the proximal plate and fragment using K-wire through a proximal locking hole to maintain the realignment (Fig. 2.d), and the status of the reduction was confirmed by fluoroscopy (Fig. 2.e).
In some cases the fracture ends were still severely displaced in a “back to back” position after preliminary reduction(Fig. 3.bd). Before inserting the plate we could insert a small hook from the distal incision along the sub-muscular tunnel and fix the hook in the medullary canal of the distal fragment, then using a traction or rotate force to reduce the displacement (Fig. 3.ef), this technique was reported in our previous reach[13].If the gap between distal clavicle and plate was wide after inserting the plate, we could use a conventional screw first to reduce the gap when we fixed the distal plate and segment (Fig. 3.gh). A conventional screw also could be used to reduce the proximal fragment displacement or minimize the gap between the plate and proximal fragment.
In some cases the sharp vertical segment could insert into the surrounding soft tissue. If there was still severely displaced after preliminary reduction(Fig. 5.b). We could insert forceps from the distal incision along the sub-muscular tunnel to clip the vertical segment, then using a traction and rotate force to unlock it (Fig. 5.cde).
The same size and type distal locking plate was used as a guide in proximal percutaneous fixation once an acceptable realignment of the fracture was achieved. A 0.5cm-sized incision was made on proximal site and fixed the proximal segment with the plate using a conventional screw (Fig. 2.f). The proximal K-wire was retrieved with the slide of the skin on clavicle region the proximal segment was fixed using a percutaneous technique through two 0.5cm-sized incisions, and at least three 3.5mm screws were fixed at proximal side of the fracture. The distal segment was fixed using 4-6 2.7mm locking screws.
Following the placement of distal and proximal screws, intra-operative fluoroscopic images were taken again to confirm the good reduction and fixation. Upon satisfactory radiograph, the wound was irrigated, the proximal incisions could be sutured using intradermic suture technique and the lateral incision was sutured in the standard fashion without a drain (Fig. 4.b, Fig. 5.i). Fluoroscopy times and operation time were also recorded.
Under general anaesthesia, the patient was placed in a supine position on a radiolucent operating table. An incision along the long axial of the clavicle was made after draping and preparation. Supraclavicular nerve was identified and protected. Sharp dissection to the bone and expose the fracture site, the fracture site was reduced and fixed with K-wires after debridement. A good reduction was confirmed by intraoperative fluoroscopy. A suitable distal clavicle anatomic locking plate was selected and fixed the fracture site with both proximal and distal segment at least three screws. Intra-operative fluoroscopic images were taken again to confirm the good reduction and fixation. The incision was sutured using standard fashion without a drain (Fig. 6).
Baseline characteristics, including age, sex, side, mechanism of injury, Robinson classification, interval from injury to surgery, and follow-up period, were assessed. The fracture pattern was classified according to Robinson classification system [14].
Clinical and radiological outcomes of the technique included reduction quality, union time, and complications. For clinical evaluation, we used the Constant-Murley score [15], which were assessed from pain, daily activities, range of motion and power at sixth month postoperative. Incision length was measured at sixth month postoperative, and the incision length was proximal incision length plus distal incision length in minimally invasive group. The quality of reduction was measured as the proportional difference in clavicle length between the injured and uninjured side [16]. An anteroposterior view X-ray was taken at the latest follow-up to reveal shortening of the clavicle. The radiographs were examined for evidence of fracture healing, short displacement or implant failure. Fracture healing was defined clinically and radiographically as the absence of pain and visible callus on anteroposterior X-ray plain. Radiographs were read by an independent examiner blinded to the study details in order to verify the short displacement and state of the bone union. Complications, such as nonunion, postoperative infection, and major neurovascular injury, were assessed.
Statistical analyses of the data were performed by an independent statistician blinded to clinical outcomes using the Statistical Package for the Social Sciences (SPSS), version 20.0 (SPSS, Inc., Chicago, IL, USA). All quantitative variables were expressed as means and standard deviation (SD) and paired student’s t tests were used to analyze the difference. Categorical variables were shown as number and percentages (%) and tested by the chi-squared test. Statistical significance was defined at the level of P < 0.05.
The baseline characteristics of the two groups are presented in Table 1. The minimally invasive group consisted of 30 patients (22 males, 8 females) and the open reduction group consisted of 28 patients (22 males, 6 females). There were no statistically significant differences in the demographics and fracture classifications between the minimally invasive group and the open reduction group.
In minimally invasive group the average proportional difference of the clavicular length was 12.0±2.0% preoperative and 0.4± 0.4% postoperative comparing with the opposite healthy side, in open reduction group the average proportional difference of the clavicular length was 11.6±1.9% preoperative and 0.4±0.1% postoperative comparing with the opposite healthy side. There was no significant difference in quality of reduction by comparing the fracture reduction in these two groups(p>0.05). The mean surgical duration in minimally invasive group was longer than that in open group (59.5±8.9 min vs. 52.2±7.2 min, P< 0.05). The mean incision length in minimally invasive group was shorter than that in open group (2.1±0.5 cm vs. 11.6±2.0 cm, P< 0.05). In minimally invasive group the mean union time was 3.3±1.1months, no patient complained of paresthesia on subclavicular region, and all patients were satisfied with the cosmesis of the wounds and showed excellent shoulder joint function with a mean Constant-Murley score of 93.8±3.8 at sixth month after the operation. In open reduction group the mean union time was 4.3±0.8months, 8 patients complained of paresthesia on subclavicular region, and only 5 patients were satisfied with the cosmesis of the wounds with a mean Constant-Murley score of 90.6±4.0 at sixth month after the operation. One patient had superficial infection in both groups. There was a significant difference in statistic by comparing union time, cosmetic result, Constant-Murley score and other complications (P<0.05). No perioperative complications, such as neurovascular injury or pneumothorax happened. Details are presented in Table 2.
Table 1
Baseline characteristics of the Minimally invasive group and Open reduction groups.
|
Minimally invasive group(n=30) |
Open reduction group(n=28) |
P-value |
Sex |
|
|
|
Male |
22(73%) |
22(79%) |
0.299 |
Female |
8(27%) |
6(21%) |
|
Side |
|
|
0.695 |
Right |
20(67%) |
20(71%) |
|
Left |
10(33%) |
8(29%) |
|
Mechanism of injury |
|
|
0.849 |
Low-energy trauma |
10(33%) |
8(29%)10 |
|
High-energy trauma |
20(67%) |
20(71%)18 |
|
Robinson classifification |
|
|
0.723 |
Type 2A2 |
3(10%) |
3(11%) |
|
Type 2B1 |
19(63%) |
20(71%) |
|
Type 2B2 |
8(27%) |
5(18%) |
|
Interval from injury to surgery |
3.5±1.1 |
3.2±1.1 |
0.449 |
Follow-up period(months) |
19.5±3.5 |
18.8±3.6 |
0.208 |
Table 2
Radiological and clinical outcome of Minimally invasive group and Open reduction groups.
|
Minimally invasive group(n=30) |
Open reduction group(n=28) |
P-value |
Surgical duration(min) |
59.5±8.9 |
52.2±7.2 |
0.001 |
Quality of reduction |
|
|
|
Preoperative short displacement |
12.0±2.5% |
11.6±1.9% |
0.517 |
Postoperative short displacement |
0.4±0.4% |
0.4±0.1% |
0.136 |
Union time(months) |
3.3±1.1 |
4.3±0.8 |
0.000 |
Constant-Murley score |
93.8±3.8 |
90.6±4.0 |
0.003 |
Cosmetic result |
|
|
|
Incision length(cm) |
2.1±0.5 |
11.6±2.0 |
0.000 |
Satisfied with cosmetic result |
30(100%) |
5(19%) |
<0.000 |
Other complications |
|
|
0.035 |
Paresthesia on subclavicular region |
0(0) |
8(29%) |
|
Postoperative infection |
1(3%) |
1(4%) |
|
Nonunion |
0(0) |
0(0) |
|
Currently the optimal treatment for displaced midshaft clavicle fractures is still controversial. Although operation is usually recommended for midshaft clavicle fractures under certain circumstances[17], it has been realized that surgery is the main reason of infection or nonunion because of extensive soft tissue dissection around the fracture site[18]. In order to reduce the complications of open reduction and internal fixation, minimally invasive plating technique was developed and widely used to treat long bone shaft fractures and has received good clinical results, especially for comminuted fractures[19,20]. Because of technical difficulties of closed reduction and its complex anatomical features (S-shaped curvature) which makes it hard to be tightly fit, performing plate fixation in midshaft clavicle fractures using minimally invasive technique is more difficult. Therefore, for midshaft clavicle fractures, the minimally invasive plating technique is rarely used. According to anatomic research and the theory of closed reduction used in conservative treatment, we have designed an indirect reduction technique for midshaft clavicle fractures using distal clavicle anatomic locking plate [12,13] that enabled the surgeon to achieve an adequate reduction and fixation without wide soft tissue stripping.
Clavicle has different muscle attaching at different part of the shaft. Most of the fractures will displace under the different deforming forces on the proximal and distal segment. The proximal segment will have upward and backward displacement because of the pulling of sternocleidomastoid muscle. The distal fragment will have inferior displacement because of the downward dragging caused by the weight of upper extremity[21]. Additionally, the pectoralis major muscle pulls the distal segment medially which cause short displacement. General anaesthesia and muscle relaxants to make sternocleidomastoid muscle and pectoralis major muscle relaxed decreases the pulling force which eased fracture reduction. In our minimally invasive technique supine position eliminates the affect of the weight of upper extremity can partially correct fracture displacement. An adequately sized bump is placed between the scapulae to make the back straight and keep the shoulder joints on an abduction position, which will primarily correct the short displacement. With external traction through the distal locking sleeve and upper extremity the short displacement could be precisely reduced. In some cases still have “back to back” position or vertical segment displacement after closed reduction which also can be easily corrected using an indirect reduction technique with the help of a small hook or forceps. After intra-operative traction on the locking sleeve the reduced state of short displacement is maintained with the placement of a K-wire through the proximal locking hole. In order to achieve a good reduction conventional screw can be placed distal or proximal to the fracture line to minimize the gap between the plate and fragment. In our minimally invasive group most of the cases had anatomic reduction, the average proportional difference in length of the clavicle improved from 12.0±2.0% preoperative to 0.4± 0.4% postoperative between the affected and unaffected side, and there was no significant difference in quality of fracture reduction when comparing with the open group which average proportional difference in length of the clavicle improved from 12.0±2.0% preoperative to 0.4± 0.1% postoperative(p>0.05). Technical errors such as poor positioning of the plate (too anterior or posterior) must be avoided to achieve a good outcome. The optimum position of the plate is with its distal anterior border and the anterior clavicle border on the same plane.
In our minimally invasive technique the anatomic locking plate was originally designed for distal clavicle fractures. It is an anatomically precontoured plate that fits the S-shape morphology and facilitates optimal implant placement. It can exactly match the clavicle’s anatomical feature and does not need any contouring. It is available in 4 lengths (92, 104, 116 and 128 mm) and has 2 locking screw hole sizes (3.5 mm on the shaft portion and 2.7 mm on the distal portion). The direction of the locking screw holes are in multiple directions which maximizes bone purchase and increases resistance to pullout forces compared with screws placed perpendicular to the plate. Unlike conventional locking plates, the distal locking screw holes are angled, which maximize pullout strength and improve overall plate stability regardless of bone quality especially in a small distal clavicle bone. Using this locking plate, the distal segment can be fixed at least eight to twelve cortices with four to six 2.7 mm multidirectional locking screws, and the proximal segment is also fixed with one 3.5mm conventional screw and two 3.5mm locking screws. Due to the rigid fixation patients were encouraged to begin early functional exercise which prevents joint stiffness. In minimally invasive group the mean Constant-Murley score was 93.8±3.8 at sixth month after the operation, and there was a significant difference when comparing with the open group with a mean Constant-Murley score of 90.6±4.0. (P<0.05)
Because of supraclavicular nerve injury the rate of incisional and proximal chest wall numbness was reported 10% to 29% after operative fixation of the clavicle [22,23]. Nathe T et al. [24] dissected 37 cadavers, found there were two or three branches of the supraclavicular nerve crossing the clavicle 97% of the time and no branch was found within 1.9cm of the acromioclavicular joint. In our minimally invasive technique the distal 1.0cm-size incision is located in this safe zone, and the rate of supraclavicular nerve injury in the two proximal percutaneous incisions is also rare. There were no clavicle region paresthesia or numbness was observed in this group. In open group there were 8 patients reported paresthesia or numbness because of supraclavicular nerve injury which was accordance with previous reports[22,23].
The minimally invasive group has a much smaller incision length(2.1±0.5 cm)when compared with open group(11.6±2.0 cm), and the obscure scar also had a better cosmetic results in comparing with other reported minimally invasive plating techniques from their typical case pictures[25,26,27,28,29].
When the minimally invasive plating technique with distal anatomic locking plate is used to treat midshaft clavicle fractures, periosteal stripping can be minimized which promote fracture union. In the current study all fractures healed within an average period of 3.3±1.1months, which was shorter when comparing with open group(4.3±0.8months). This might be not only because of periosteal circulation could be preserved with the minimization of the soft tissue stripping using percutaneous technique but also a good reduction could be well maintained through a rigid fixation. Minimally invasive surgery using distal clavicle anatomic locking plate seems to be a good option for the treatment of midshaft clavicle fractures with satisfactory cosmetic result and excellent return to function. It keeps soft tissue envelope, periosteum, and vascular integrity of fracture site, decreasing infection rates and enhancing fracture callus formation. In addition, this technique had an advantage of not requiring a special instrument and ease of performance.
There are some limitations to the present study. First, the relatively small number of cases may limit statistical reliability. Second, we have selection bias because the selection of the technique was not randomized. Third, the present study cannot prove the superiority of minimally invasive group over open group in terms of surgical duration. However, with relatively short union time, good cosmetic result and less complications we believe that comparable results can be meaningful.
Minimally invasive surgery using distal clavicle anatomic locking plate seems to be a good option for the treatment of midshaft clavicle fractures with satisfactory cosmetic result and excellent return to function.
Not applicable
The authors declare that they have no competing interests.
Zhejiang Province Public Welfare Technology Application Research Project (Award Number: LGF20H060008)
All authors have contributed significantly to the study design, date collections, date analysis, writing the whole process.