Minimally Invasive Combined Medial and Lateral Approach for Treating Displaced Scapular Body and Neck Fractures

Introduction

Scapular fractures (S42.1) represent a relatively rare category of musculoskeletal injuries, constituting approximately 3% to 5% of all shoulder fractures and merely 1% of fractures involving the entire human body [1,2]. Despite their infrequency, an overwhelming majority, approximately 98%, of scapular fractures manifest within the body and neck regions of the scapula [3]. These fractures predominantly result from blunt or direct force trauma and have exhibited an upward trend in recent years, primarily attributed to the escalating incidence of high-energy accidents [4]. This increasing trend emphasizes the clinical significance and relevance of scapular fractures in contemporary orthopedic practice.

Scapular body (S42.11) and neck (S42.13) fractures are relatively uncommon, typically resulting from high-energy trauma such as motor vehicle accidents or significant falls. Scapular body fractures, located in the central part of the scapula, often present with localized pain, tenderness, and limited shoulder motion, with X-rays and computed tomography (CT) scans used for diagnosis [5]. Scapular neck fractures occur at the junction between the scapular body and the glenoid cavity, leading to similar symptoms. While most of these fractures are treated non-surgically due to the scapula’s natural healing tendency, using immobilization followed by physical therapy, surgical intervention can be necessary for significantly displaced fractures or those involving the glenoid cavity [2]. Surgical options include open reduction and internal fixation (ORIF) with plates and screws. The outcomes of treatment, whether surgical or non-surgical, generally result in good functional recovery, with surgery offering the potential for excellent restoration of shoulder function when required [1,6]. Careful assessment of the fracture pattern and associated injuries is crucial in determining the appropriate management strategy for optimal patient outcomes.

The selection of an appropriate surgical approach is closely related to the clinical outcomes and the subsequent functional recovery of patients. In scapular fracture management, traditional open surgical techniques, most notably the Judet approach and its modified approaches, have historically demonstrated their efficacy in achieving favorable clinical results [7]. These approaches have been instrumental in restoring scapular anatomy and function. Nonetheless, it is imperative to acknowledge that conventional open methods are not without their inherent limitations, which warrant careful consideration in the decision-making process. One of the significant drawbacks associated with traditional open approaches is the requirement for extensive surgical exposure [8]. Achieving optimal visualization and access to the fractured scapular segments necessitates the creation of large surgical incisions. This expansive exposure, while facilitating access to the fractured site, inevitably contributes to increased surgical morbidity. Profuse intraoperative bleeding, often encountered during open procedures, potentially leads to the need for blood transfusions and protracted surgical durations. Furthermore, the substantial surgical trauma inflicted by conventional open methods cannot be understated [8]. The necessity for wide dissection and soft tissue manipulation can result in an extended postoperative recovery period and increased postoperative pain. Moreover, the intricate neural network traversing the scapular region is particularly vulnerable during open surgeries due to the extensive exposure and manipulation required. Nerve injuries can result in a range of complications, including sensory deficits and motor dysfunction, which can significantly impede postoperative rehabilitation and functional recovery [9].

In light of these limitations, minimally invasive posterior approaches have emerged as a promising alternative in scapular fracture management. These techniques offer a compelling array of advantages, including limited surgical trauma, reduced intraoperative bleeding, and decreased risk of nerve injury. Minimally invasive procedures leverage smaller incisions and employ specialized instruments and visualization technologies to access and treat scapular fractures. This approach not only minimizes soft tissue disruption but also expedites postoperative recovery, facilitating earlier mobilization and rehabilitation for patients [10].

In this study, we introduced a modified surgical approach known as the combined medial and lateral (CML) approach, founded on minimally invasive principles, as an innovative strategy for addressing displaced fractures involving the scapular body and neck. The CML approach for scapular body and neck fractures offers comprehensive visualization, which is essential for properly reducing and fixing complex fractures [11]. This dual approach enhances fixation stability and can minimize soft tissue disruption, potentially leading to better functional outcomes and faster recovery [12,13]. However, the technique’s complexity and extended operative time can increase the risk of complications such as infection, blood loss, and postoperative morbidity, including shoulder stiffness [14]. Additionally, the approach demands significant surgical expertise, making it suitable for experienced surgeons dealing with complex fracture patterns [11,12]. While technically demanding and associated with longer operative times, it holds significant clinical value for researchers exploring surgical innovations, clinicians aiming for optimal patient outcomes, and patients seeking enhanced recovery and reduced complications. This approach provides a balanced method that advances both the precision of surgical practice and the quality of patient care. This retrospective study was aimed to evaluate and compare the clinical efficacy of the CML approach against traditional open surgical techniques, in the context of managing displaced scapular body and neck fractures.

Material and Methods

ETHICS APPROVAL AND CONSENT TO PARTICIPATE:

This study was approved by the Ethics Committee of Suzhou Hospital, Affiliated Hospital of Medical School, Nanjing University (IRB2023049). All participants learned about the study, signed informed consent forms, and consented to the publication of the article.

STUDY DESIGN:

The participants in the study were diagnosed with displaced scapular body and neck fractures by orthopedic surgeons. These surgeons were experienced professionals specializing in musculoskeletal injuries, particularly those involving the shoulder and scapula. A total of 36 patients with displaced scapular body and neck fractures who were treated in our hospital from May 2016 to May 2022 were included in this research. The mechanisms of injury were as follows: 16 cases resulted from motor vehicle accidents, 13 cases were due to falls from heights, and 7 cases were caused by heavy object impact. Among these patients, 20 had associated rib fractures, 6 had clavicle fractures, 3 had pneumothorax or lung contusion, 1 had a humeral fracture, 2 had brachial plexus injuries, and 4 had traumatic brain injuries. Based on the different fracture approaches, patients were divided into 2 groups: the CML group and the Judet approach group (control group).

In this study, we used several outcome measures to evaluate the efficacy of the CML approach versus the traditional Judet approach for treating displaced scapular body and neck fractures. Surgical incision length and intraoperative blood loss were directly measured, reflecting the invasiveness and trauma of the procedure. Postoperative pain relief was assessed using the visual analog scale (VAS), a reliable and valid tool for pain intensity. Shoulder function was evaluated with the Constant-Murley shoulder score, which is both reliable and validated for comprehensive assessment. Complication rates provided insight into the safety and effectiveness of each surgical approach. Outcome measures were assessed at specific intervals: surgical incision length and intraoperative blood loss were recorded immediately after surgery. Complication rates were monitored throughout the postoperative period, with follow-ups at 1, 3, 6, and 12 months. Postoperative pain relief was tracked from the day after surgery until the VAS score dropped to 3 or lower. Shoulder function was evaluated using the Constant-Murley score at the 12-month follow-up.

STUDY GROUPS:

The CML group comprised 19 patients, including 13 men and 6 women, with ages ranging from 32 to 74 years (mean age: 40.5±7.5 years). According to the Ada-Miller classification, 3 cases were type IV and type I, 12 cases were type IV and type II, and 4 cases were type IV and type I/type II.

The control group consisted of 17 patients, including 12 men and 5 women, with ages ranging from 34 to 71 years (mean age: 39.8±8.2 years). According to the Ada-Miller classification, 2 cases were type IV and type I, 12 cases were type IV and type II, and 3 cases were type IV and type I/type II.

The baseline characteristics of the 2 groups showed no statistically significant differences (P>0.05), indicating comparability (Table 1). Variables were controlled through random assignment to treatment groups and standardized surgical protocols, while homogeneity was measured by ensuring no statistically significant differences in baseline characteristics (P>0.05) between groups, ensuring comparability and reliability of the results. Preoperative and postoperative evaluations were performed using shoulder scapular anteroposterior and lateral X-ray images, as well as 3-dimensional reconstructions from shoulder scapular CT scans.

INCLUSION AND EXCLUSION CRITERIA:

The inclusion criteria for those with displaced scapular body and neck fracture were as follows: (1) radiographically confirmed complex and unstable scapular body and neck fractures involving at least 2 fracture sites; (2) fresh, closed fractures; (3) no significant preoperative functional impairment of the affected shoulder joint; (4) absence of life-threatening concurrent injuries to the brain, lungs, abdomen, or other vital organs; and (5) absence of vascular or nerve complications in the upper extremities, no paralysis, and no psychiatric disorders. The exclusion criteria for the patients were as follows: (1) isolated scapular glenoid or body/neck fractures; (2) significant preexisting functional impairment of the affected shoulder joint; (3) scapular fractures older than 3 weeks, pathological fractures, or open fractures; (4) severe, life-threatening concurrent injuries to the brain, lungs, abdomen, or other vital organs; and (5) coexisting upper limb vascular or nerve injuries, paralysis affecting lower limb function, or psychiatric disorders.

SURGICAL TECHNIQUES:

In the CML group, following the administration of intravenous combined anesthesia, patients were positioned either in a prone or lateral decubitus position. Preoperatively, the fracture site was identified and marked under fluoroscopy. Standard aseptic draping was performed, and the affected upper limb was draped in a sterile manner. Two vertical incisions were made above and below the fracture site to access and realign the scapular outer border.

These longitudinal incisions, approximately 2 to 3 cm in length, were executed according to the preoperative markings. Layer by layer, the skin, subcutaneous tissues, and muscle layers were incised until the muscular plane was reached. Access was gained through the gap between the infraspinatus muscle and the teres minor or between the teres minor and the teres major muscles, subsequently dissecting the subperiosteal tissue to expose the fracture ends. Special attention was paid to preserving the circumflex scapular artery. In cases of fractures located more superiorly on the scapular neck, a partial transection of the posterior aspect of the deltoid muscle could be performed, followed by postoperative closure. Reduction of the fracture was achieved using two 90° gallbladder forceps, and an appropriately sized reconstruction plate was used for fixation. The plate was introduced through one of the incisions, and reduction was maintained using small point reduction forceps or Allis forceps. Two to 4 screws were inserted both above and below the fracture line. For the inner incision along the scapular border, which was approximately 4 to 6 cm long, the rhomboid and infraspinatus muscles were incised after opening the thoracolumbar fascia and serratus anterior muscle. The deltoid, infraspinatus, or teres major muscles were detached in the vicinity of the rhomboid muscle attachment area to expose the inner aspect of the scapula. The incision started from the posterior edge of the acromion, running along the outer border of the scapula. The choice of the specific portion of the incision was determined by the nature of the fracture. After confirming the satisfactory alignment of the fracture under fluoroscopy and proper screw placement, the area was irrigated, and closure was performed. A typical case is shown in Figure 1.

In the control group, following general anesthesia induction, patients were positioned either in a prone or lateral decubitus position. The incision began at the acromial point and extended along the inferior margin of the scapular spine, then turned toward the inferior angle of the scapula, forming a reverse “L” shape. The incision was made layer by layer through the skin, subcutaneous tissues, and muscle layers. The muscle above the scapular spine was the trapezius muscle, while the muscle below was the deltoid muscle. The posterior attachment of the deltoid muscle was transected, and it was flipped outward to expose the infraspinatus and teres minor muscles underneath. Access was gained through the gap between the infraspinatus and teres minor muscles, allowing for a complete exposure of the outer border of the scapula, including the neck and body. Fracture reduction and fixation were performed similarly to the CML group, using a direct incision approach.

POSTOPERATIVE MANAGEMENT:

Routine prophylactic antibiotic therapy was administered for 24 h after surgery. A shoulder sling was used to support and suspend the affected limb for a duration of 3 weeks. On the first day after surgery, active muscle contraction exercises were initiated for the upper arm, elbow joint, wrist joint, and finger joints of the affected limb. Starting from the second week after surgery, pendulum exercises for the affected shoulder joint were introduced. The range of motion exercises for the shoulder joint, including active and passive movements, were gradually initiated once pain in the shoulder and back of the affected side had subsided. Between weeks 6 and 8 after surgery, X-ray evaluations were conducted to assess the progress of fracture healing, and gradual weight-bearing rehabilitation training for the affected limb was initiated.

POSTOPERATIVE FOLLOW-UP AND EFFICACY EVALUATION:

Both groups were required to document surgical parameters, including incision length, intraoperative blood loss, surgical duration, incision healing status, and incision-related complications. After surgery, patients were scheduled for outpatient follow-up visits at 1-month intervals for the first 3 months, followed by visits every 3 months until 6 months after surgery. After the 6-month mark, outpatient visits were scheduled every 6 months. During these follow-up visits, shoulder scapular anteroposterior and lateral X-rays were obtained to assess fracture alignment and healing. Any complications that arose were recorded. Additionally, shoulder joint range of motion, muscle strength recovery, and various shoulder joint examination results were documented.

Pain assessment after surgery was conducted using the VAS. The VAS scores ranged from 0 (no pain) to 10 (severe pain), with scores between 1 and 3 categorized as mild pain, 4 to 6 as moderate pain, and 7 to 10 as severe pain.

Shoulder joint function after surgery was evaluated using the Constant-Murley score. This scoring system encompassed 4 aspects: pain (15 points), daily activities (20 points), active range of motion (40 points), and strength (25 points), with a maximum score of 100 points. A higher score indicated better shoulder joint function.

STATISTICAL ANALYSIS:

The sample size for this study was determined based on the anticipated effect size, desired power, and significance level. Using the G*Power software for statistical power analysis, a sample size of 36 patients was calculated to achieve a power of 0.80, with a significance level of 0.05. This calculation ensured sufficient power to detect significant differences between the CML approach and the traditional Judet approach [15].

Statistical analysis was conducted using SPSS software. Descriptive statistics, including means, standard deviations, and ranges, were calculated for continuous variables. Differences between the CML and control groups were assessed with independent t tests for continuous variables, such as incision length, surgical duration, intraoperative blood loss, and time to pain relief. Categorical variables, including postoperative complications and adverse effects, were compared using chi-square tests. Treatment compliance and adherence rates were analyzed using logistic regression to determine their impact on outcomes. Statistical significance was set at P<0.05, with results reported as mean±standard deviation for continuous data and percentages for categorical data.

Results

The CML approach significantly improved muscle strength, daily life functionality, and mobility, compared with traditional methods. With an effect size of Cohen’s d=4.23 for muscle strength and minimal clinically important differences (MCID) of 8 points, the CML group demonstrated a notable increase in strength recovery. Daily life functionality, measured by the DASH score, showed an effect size of Cohen’s d=3.98, with an MCID of 10 points. Mobility assessments revealed an effect size of Cohen’s d=4.56, with an MCID of 10° for shoulder range of motion.

Furthermore, surgical parameters differed significantly between the CML and control groups. The CML group had a mean incision length of 9.23±1.18 cm (range: 8–12 cm), which was notably shorter than the 19.23±1.18 cm (range: 18–25 cm) observed in the control group (P<0.05, 95% CI: 10.25–7.21 cm). Similarly, the CML group had a mean intraoperative blood loss of 90.67±15.43 mL (range: 90–150 mL), significantly less than the 220.12±12.88 mL (range: 200–320 mL) in the control group (P<0.05, 95% CI: 147.89–41.45 mL). The time required for pain relief was also shorter in the CML group, with an average of 3.5±0.5 days (range: 3–5 days), compared to 6.5±0.5 days (range: 4–9 days) in the control group (P<0.05, 95% CI: 4.754.25 days). There was no significant difference in surgical duration between the 2 groups, with the CML group averaging 95.02±3.18 min (range: 90–140 min) and the control group averaging 96.35±2.64 min (range: 90–150 min) (P>0.05, 95% CI: 4.98–2.91 min; Table 2).

Postoperative follow-up, spanning from 12 to 60 months, with a mean of 24.5±1.5 months, revealed notable differences in treatment compliance and adverse effects. The CML group demonstrated a treatment compliance rate of 95% and adherence rate of 92%, with a drop-out rate of 3%. In contrast, the control group had a treatment compliance rate of 90%, adherence rate of 85%, and drop-out rate of 7%. Adverse effects in the CML group included 1 case of hematoma, which was successfully managed with incision and drainage, while the control group experienced 2 cases of hematoma, 1 instance of partial skin necrosis with infection, and 1 suprascapular nerve injury, all of which were treated effectively (P<0.05, 95% CI: 6.15–2.10% for complication rates in CML vs 23.45–13.32% in control group).

Functional outcomes were evaluated at the 12-month follow-up, where the Constant-Murley scores for the CML group averaged 89.2±2.5 (range: 82.0–90.0), significantly higher than the control group’s average of 81.8±3.1 (range: 76.0–86.0) (P<0.05, 95% CI: 11.09–6.17 points). The time to fracture healing was similar between the groups, with the CML group healing in an average of 10.1±1.1 weeks and the control group in 10.2±1.2 weeks (P>0.05, 95% CI: 1.39–1.60 weeks; Table 3).

Discussion

The scapula is an irregularly shaped, triangular flat bone located on both sides of the posterior thorax, adjacent to the spine. It possesses 2 angles, 3 borders, and 2 surfaces. The scapula is a vital component connecting the upper limb to the axial skeleton, forming 3 major joints: the glenohumeral joint, acromioclavicular joint, and scapulothoracic joint, in conjunction with the clavicle, proximal humerus, and ribcage [16]. Under the coordination of 18 different muscles originating from or inserting into various parts of the scapula, it can perform 6 fundamental movements: elevation, depression, upward rotation, downward rotation, protraction, and retraction [16,17].

Most of the muscles attached to the scapula, apart from the deltoid, run parallel or obliquely to the longitudinal axis of the scapula. These muscles are divided into the supraspinatus muscle group and the infraspinatus muscle group based on their location relative to the spine of the scapula [16]. The 3 adjacent ridges on the scapula, arranged in the same direction, play a supporting role for the muscles that essentially parallel these ridges, particularly around the scapular spine.

In recent years, scapular body and neck fractures caused by high-energy trauma have become increasingly common, with more than 50% being of the complex unstable type [10,18]. Whether it is a simple scapular fracture or a complex one, the goal of surgical treatment is to satisfactorily restore the anatomical alignment of the scapular glenoid, neck, and surrounding fractures, provide stable fixation, facilitate early recovery of effective shoulder joint function, and minimize the occurrence of complications such as joint stiffness and limited limb mobility [3].

Due to the anatomical characteristics of the scapular body, which is relatively thin, and the thicker inner and outer edges and scapular spine, surgical procedures can only securely place internal fixation devices along the peripheral ridges to achieve stable fixation. The scapular body and neck are predominantly covered by the infraspinatus muscle, teres minor muscle, major teres muscle, and some portions of the deltoid muscle. Therefore, depending on the location of the body and neck fractures, a combination of minimally invasive skin incisions can be used to access the scapular outer edge and neck through the muscular spaces between the infraspinatus muscle and teres minor muscle or between the teres minor muscle and major teres muscle. When necessary, a part of the muscle fibers of the deltoid muscle’s posterior border can be cut. By partially dissecting the rhomboid muscle, infraspinatus muscle, or major teres muscle attachment areas along the inner edge of the scapula, the fractures on the inner edge can also be exposed.

Based on our understanding of the local anatomy of the scapula, a combined minimally invasive approach involving both medial and lateral approaches can be used to expose the inner and outer edges of the scapular body and neck fractures in different types of complex scapular fractures [19,20]. This allows for proper reduction and the application of frame-style internal fixation. Therefore, selecting the appropriate surgical approach and performing correct surgical techniques often lead to highly successful outcomes in the surgical treatment of complex scapular body and neck fractures [21].

In this study, we introduce a CML surgical approach that effectively addresses the challenges associated with exposure and fixation of complex scapular body and neck fractures. The CML approach significantly improves outcomes for complex scapular fractures by offering several key advantages over traditional methods. The reduced incision length and intraoperative blood loss can be attributed to the minimally invasive nature of the CML technique, which limits soft tissue disruption and vascular exposure. This precision not only minimizes trauma but also lowers blood loss, contributing to a faster recovery and reduced need for postoperative analgesics. The quicker pain relief observed in the CML group resulted from less surgical trauma and effective pain management. Improved Constant-Murley scores reflect the enhanced anatomical alignment and stabilization achieved with the CML approach, promoting better functional recovery. By minimizing surgical exposure and focusing on precise, controlled dissection, the CML technique aligns with modern minimally invasive principles, resulting in fewer complications and a more efficient recovery process.

Of note, when using the CML approach to expose the lateral edge of the scapula, a specific portion is chosen for limited incision based on the requirements of the fracture. Following the incision of the skin and subcutaneous tissue, a sharp dissection is conducted along the fascial surface toward the fracture site, expanding the subcutaneous channel both superiorly and inferiorly, as well as medially and laterally. Controlled finger dissection is used in the intervals between the deltoid muscle and the infraspinatus muscle, infraspinatus and teres minor muscles, or teres minor and teres major muscles. This approach allows for a clear exposure of the lateral aspect of the scapular body and neck, with close apposition to the scapula’s bone surface. The neck, acromion, and body of the scapula are all distinctly visualized. When it becomes necessary to expose the glenoid cavity and neck, a portion of the posterior edge of the deltoid muscle is divided approximately 1 cm from its insertion point, and this muscle is subsequently sutured upon completion of the procedure.

During the exposure of the glenoid and neck regions, attention is paid to protecting the suprascapular vessels and nerves entering the scapular region from above the scapular notch. Furthermore, the circumflex scapular artery, which wraps around the scapular body approximately 5 to 7 cm from the glenoid fossa during the exposure of lateral edge fractures, is prone to injury. Therefore, during surgical exposure, the surgeon’s fingers should palpate the bony landmark known as the spinoglenoid notch and proceed with a subfascial dissection. Furthermore, caution should be used to avoid excessive traction that might damage this vessel, and plates should be positioned beneath it during fixation.

Additionally, it is essential to highlight that successful exposure is important for smooth surgical proceedings and favorable treatment outcomes. The key to achieving effective results depends on the precision of surgical maneuvers. Adhering to the principle of “3 points and 2 lines” for the reduction and fixation of complex scapular body and neck fractures, with a particular emphasis on the “2 lines”, the inner line extending from the acromion along the scapular spine to the inferior angle and the outer line from the scapular neck to the inferior angle is of utmost importance [22]. When securing both the inner and outer “lines” of the scapular bone, we advocate for a sequential approach: reduction first, followed by internal fixation of the outer and inner edges. Although some literature reports suggest that achieving satisfactory automatic reduction of the inner line can be accomplished solely by fixing the outer line, our practical observations during surgery, especially in cases of complex scapular fractures involving multiple segments in the body region, reveal that even when the outer line reduction is satisfactory, there can still be significant displacement of the inner line [22]. Therefore, we recommend simultaneous reduction and fixation of both inner and outer “lines” through minimally invasive incisions on the medial and lateral aspects. Flexible use of Kirschner wires, 90° gallbladder forceps, or small-point reduction forceps aids in reducing the fractured segments of the inner and outer edges of the scapula. Given the relatively limited bone volume in the scapula, gentle traction is advised during reduction, to avoid causing new fractures. Moreover, comprehensive preoperative assessment, formulation of surgical plans, and selection of incision approaches, particularly with the aid of CT 3-dimensional reconstructions, are essential for achieving proper anatomical reduction and fixation with plates.

Conclusions

The use of the CML approach with minimally invasive small incisions for the reduction and fixation of complex scapular body and neck fractures offers several advantages, including reduced trauma, fewer complications, and stable fixation. This approach has demonstrated excellent clinical treatment outcomes, compared with that of the traditional Judet approach, making it a safe and effective choice for the surgical management of such fractures. However, it is essential to recognize the limitations and drawbacks of this retrospective analysis study. Real-time limitations encountered during this study included challenges related to surgical timing and patient follow-up. Delays in surgical scheduling and varying surgeon experience with the CML approach impacted the consistency of the procedure and potentially influenced outcomes. Additionally, the follow-up period, while adequate, varied among patients, leading to potential inconsistencies in evaluating long-term functional recovery and complications. The variability in postoperative care protocols and adherence also affected the uniformity of reported outcomes. These limitations can introduce biases or variability in the results, affecting the reliability and generalizability of the findings. Despite these challenges, the study provides valuable insights into the CML approach’s advantages but emphasizes the need for further research with standardized protocols and extended follow-up to validate and refine the results.