Entrapped periosteum in distal tibial physeal fracture: Is open reduction always necessary? – A case report

Abstract

Introduction

Distal tibial physeal fractures are common in pediatric trauma and are typically managed with closed reduction. However, in some cases, reduction failure is due to soft tissue interposition, particularly periosteum, which may necessitate open reduction. This case examines whether open reduction is indicated when confirming periosteal interposition.

Case presentation

We report the case of a 14-year-old male with a displaced Salter-Harris type II distal tibial fracture and concurrent fibular fracture sustained during sports activity. Closed reduction attempts failed, and MRI revealed periosteal interposition. Open reduction via anteromedial approach confirmed periosteal entrapment, which was removed, followed by internal fixation with smooth pins. Postoperative recovery was uneventful, and at 12-month follow-up, full union was observed with no evidence of physeal arrest. The patient had regained complete ankle range of motion, was pain-free in daily activities.

Discussion

Comparison with previously published reports reveals that while not all cases of periosteal interposition lead to growth arrest, the presence of entrapped periosteum, particularly in the setting of failed closed reduction, poses a non-negligible risk. Preoperative MRI facilitates early diagnosis and surgical planning. Open reduction, when selectively applied, may prevent complications such as angular deformity or physeal bar formation.

Conclusion

Periosteal entrapment should be considered in irreducible distal tibial physeal fractures. MRI evaluation and timely open reduction in selected cases allow for effective treatment and favorable outcomes. Surgical decisions should be individualized, guided by imaging and intraoperative findings.

Highlights

• • Early MRI diagnosis prevents long-term complications

  Preoperative MRI helps confirming periosteal interposition.

• • Not all cases require open reduction, but some clearly benefit

  While periosteal entrapment doesn’t always mandate surgery, open reduction may save possible growths arrest.

• • Successful outcome through targeted surgical intervention

  Caese by case decision for open reduction and removal of the interposed periosteum is needed.

• • Individualized decision-making is crucial

  The article stresses that decisions on open reduction should be individualized, based on patient age, growth potential, reduction success, and imaging findings.

• • Leaving the entrapped periosteum untreated poses a risk

  Clinical and experimental data suggest that retained periosteum may either resorb or contribute to physeal bar formation.

1. Introduction

Physeal fractures of the distal tibia are among the most common growth plate injuries in children and adolescents, typically resulting from rotational or valgus stress injuries. Although Salter-Harris type I and II fractures are often managed successfully with closed reduction and casting, failure of reduction may indicate interposition of soft tissue structures, most frequently the periosteum [[1], [2], [3]].

Entrapment of the periosteum within the fracture site can act as a mechanical block to reduction and has been increasingly recognized through preoperative MRI in both distal tibial and femoral injuries [2,[4], [5], [6], [7]]. While some studies suggest that a residual physeal gap >3 mm after attempted closed reduction may correlate with periosteal interposition and justify open surgery, the necessity of open reduction in all such cases remains controversial [7,8].

Animal and histologic studies have further explored the fate of interposed periosteum, suggesting a potential for either degradation, integration into remodeling tissue, or contribution to physeal bar formation [9]. Yet, clinical outcomes following open versus conservative management vary, and no consensus exists regarding the universal indication for surgical removal.

This case report describes a pediatric patient with a distal tibial Salter-Harris fracture complicated by entrapped periosteum. While some studies, such as Gruber et al., suggest that interposed periosteum may occasionally resolve spontaneously without leading to growth disturbance, others, including Li et al., advocate for early surgical removal to minimize the risk of physeal arrest [4,9]. Using this case as a framework, we aim to evaluate whether imaging-confirmed periosteal interposition invariably mandates open reduction and to highlight the clinical considerations that guide treatment decisions in such scenarios. This article has been written in accordance with the SCARE guidelines [10].

2. Case presentation

A 14-year-old male presented to the emergency department following a twisting injury to his right ankle sustained while playing football. He had no relevant past medical history or medication use. His weight was 40 kg and height 145 cm, corresponding to a BMI of 19. The injury involved his dominant limb. On initial evaluation, there was significant swelling and visible deformity of the right ankle. Physical examination revealed marked tenderness over the distal tibia, and the patient was unable to bear weight. Neurovascular status was intact on presentation.

Initial radiographs demonstrated a displaced Salter-Harris type II fracture of the distal tibial physis, along with a transverse fracture of the distal fibula and associated valgus angulation (Fig. 1). Under general anesthesia, closed reduction under fluoroscopic guidance was attempted. However, anatomical alignment could not be achieved, raising suspicion for soft tissue interposition. To avoid potential iatrogenic damage to the growth plate through repeated manipulations, the decision was made to proceed with open reduction.

Fig. 1.

Initial radiographs demonstrate a displaced Salter-Harris type II fracture of the distal tibial physis with associated transverse fracture of the distal fibula.

Preoperative MRI was performed to further evaluate the cause of irreducibility and confirmed periosteal interposition at the fracture site (Fig. 2). Open reduction was then performed via an anteromedial incision over the distal tibia. Upon exposure of the fracture site, periosteal tissue was clearly interposed between the metaphysis and epiphysis, preventing proper reduction (Fig. 3).

Fig. 2.

Coronal and sagittal T2-weighted MRI sequences demonstrating periosteal interposition within the distal tibial physis.

Fig. 3.

Intraoperative photograph demonstrating periosteal interposition at the distal tibial physeal fracture site.

Traction on the distal fragment combined with careful retraction of the interposed periosteum allowed for an easy reduction of the fracture. Once proper alignment was confirmed fluoroscopically, internal fixation was performed using two 1.5 mm smooth pins. Immediate postoperative radiographs are shown in Fig. 4.

Fig. 4.

Postoperative radiograph demonstrating anatomic reduction without evidence of physeal gap at the fracture site.

Postoperatively, a long leg cast was applied for six weeks with non-weight-bearing instructions. The rationale for our postoperative protocol was based on standard practice for distal tibial physeal fractures. Six weeks of initial immobilization in a long leg cast was chosen to ensure adequate stability and soft tissue healing, particularly in the setting of physeal involvement. Pin removal at six weeks corresponded with expected early union and was intended to minimize the risk of pin tract infection. Transitioning to a short leg cast with gradual weight-bearing for an additional six weeks allowed progressive functional recovery while maintaining protection of the physis. At six-month follow-up, radiographic union was observed with no evidence of deformity or physeal disturbance (Fig. 5). At one-year follow-up, the patient demonstrated complete union, full ankle range of motion, and was able to return to sports (Fig. 6).

Fig. 5.

Six-month follow-up radiograph showing complete fracture union without evidence of physeal injury or deformity.

Fig. 6.

Radiographs at one-year follow-up showing complete union with full range of motion and absence of deformity in both coronal and sagittal planes.

3. Discussion

Periosteal interposition is a recognized cause of irreducibility in Salter-Harris fractures of the distal tibia. Several reports have emphasized that persistent physeal widening (>3 mm) following attempted closed reduction should raise suspicion for soft tissue entrapment, most commonly the periosteum [4,7,8,11,12]. MRI can play a pivotal role in identifying such interposition preoperatively, as was evident in our case, allowing the surgical team to plan appropriately for open reduction [1,2,5,7].

Table 1 provides a comparative overview of published case reports and experimental studies addressing periosteal entrapment in physeal fractures. It summarizes fracture type, nature of soft tissue interposition, diagnostic modality, management strategy, and clinical outcomes. This comparison highlights the variability in clinical courses and outcomes, reinforcing the importance of individualized surgical decision-making based on imaging findings and intraoperative observations [Table 1].

Table 1.

Comparison of published case reports and studies involving periosteal and other soft tissue interposition in physeal fractures.

Author (year)	Case / age	Fracture type	Entrapment	Diagnosis modality	Reduction type	Outcome
Chen et al. (2015)	N = 1 / 13Y/O - M	Distal femur, SH II	Periosteum	MRI	Open	Leg length discrepancy
Li et al. (2011)	N = 1 / 14Y/O - M	Distal tibia, SH II	Periosteum	MRI	Open	Good outcome, no arrest
Segal et al. (2011)	N = 2 / 12Y/O - M	Distal femur, SH II	Periosteum	MRI	Open	Central osseous physeal bar
Gruber et al. (2002)	Rat model / not reported	Proximal tibia	Periosteum	Histology	N/A	Variable: resorption or bar
Moura et al. (2012)	N = 1 / 11Y/O - F	Distal femur, SH I	Periosteum	MRI	Open	Not reported
Doshi et al. (2021)	N = 1/ 14Y/O - M	Distal tibia, SH II	Tibialis posterior tendon	Intraop finding	Open	No deformity and closing physis

Periosteal entrapment has been increasingly recognized as a key factor in distal tibial physeal fractures, particularly in Salter–Harris type II and triplane injuries. Park et al. reported periosteal interposition in up to 72 % of adolescents, most commonly located at the anterolateral physis [13]. Similarly, Soulier et al. described cases where periosteum or tendons prevented successful closed reduction, necessitating open surgery for anatomic alignment. These findings suggest that a residual physeal gap after reduction is not simply a benign radiographic sign but may indicate soft-tissue interposition that can compromise long-term outcomes [13].

Several predictors of premature physeal closure have been described, including fracture displacement, metaphyseal comminution, quality of reduction, and younger age. A residual gap greater than 3 mm has emerged as a particularly strong radiographic predictor and is frequently associated with periosteal incarceration [14]. Early detection through MRI or careful radiographic evaluation may therefore guide the need for surgical exploration. While some cases of periosteal entrapment remain asymptomatic, accumulating evidence suggests that timely removal of interposed tissue may reduce the risk of PPC and subsequent angular deformity [13].

The necessity of open reduction in these cases remains debated. While many authors advocate for open reduction to restore anatomical alignment and prevent growth disturbances, others suggest that some entrapped periosteum may resolve spontaneously without leading to physeal arrest [[5], [6], [7],9,13,[15], [16], [17]]. Gruber et al., in a controlled animal model, found that interposed periosteum may follow one of two pathways: it may be resorbed by multinucleated giant cells and integrated into the healing process, or it may persist between epiphyseal and metaphyseal cartilage, potentially contributing to physeal bar formation and subsequent arrest [6,9,15,16].

However, the clinical relevance of this histologic observation is nuanced. Chen et al. and Segal et al. reported cases in which open reduction and removal of entrapped periosteum were performed, yet the patients still developed premature physeal closure [2,6,7]. These findings suggest that periosteal interposition may not be the sole cause of growth disturbance, but rather a surrogate marker of more severe initial injury to the physis itself, particularly to the germinal zone, which is critical for longitudinal growth.

On the other hand, favorable outcomes have also been reported following timely open reduction. In the case report by Li et al., the patient undergoing open reduction for confirmed periosteal entrapment demonstrated normal healing and no signs of physeal bar or deformity on follow-up imaging [4,5].

Several authors have cautioned that repeated attempts at closed reduction in the presence of suspected soft tissue interposition may themselves cause iatrogenic injury to the physis and increase the risk of growth arrest. In such cases, early recognition of irreducibility and timely conversion to open reduction is recommended to achieve anatomical alignment while minimizing additional physeal damage [13]. These observations support the notion that surgical removal of the mechanical block may prevent abnormal healing, particularly if the physis has not already been critically injured at the time of trauma.

Notably, some cases treated non-operatively have also avoided growth arrest. Gruber et al. observed that in a subset of rats with retained periosteum, the tissue was either resorbed or displaced, and only a minority developed significant bar formation [6,9]. Nevertheless, in their model, bar formation was significantly more likely when periosteal entrapment was combined with physeal cartilage ablation, a condition that might analogously occur in high-energy pediatric injuries.

In addition to conventional open reduction and internal fixation, alternative approaches have been described in recent literature. Arthroscopic-assisted reduction and fixation has been increasingly applied in pediatric ankle fractures, offering improved visualization of the articular surface, precise removal of interposed soft tissue, and the potential to minimize soft tissue disruption [18,19].

Another evolving option is the use of absorbable implants, such as polylactide (PLA) or polyglycolide (PGA) devices. Meta-analyses of randomized trials demonstrate that absorbable implants achieve comparable radiographic and functional outcomes to metallic implants, with the added advantage of obviating the need for hardware removal and reducing the risk of implant-related complications [20,21]. While these modalities were not employed in the present case, they represent promising strategies that merit consideration in selected patients.

The decision to perform open versus closed management in distal tibial physeal fractures should be guided by both radiographic and clinical findings. When closed reduction fails to achieve anatomical alignment, a residual physeal gap greater than 3 mm is present, and MRI demonstrates periosteal interposition, open reduction becomes the preferred approach. Surgical exploration in this context not only allows direct removal of the obstructing tissue but also reduces the risk of repeated manipulations that may cause iatrogenic damage to the growth plate. While MRI remains the ideal modality for detecting periosteal interposition, in low-resource settings, ultrasound or CT may serve as useful adjuncts when MRI is not available. These considerations highlight that open reduction is most justified when clear mechanical and imaging evidence point to irreducibility.

On the other hand, when closed reduction is successful and anatomic alignment is achieved; percutaneous pinning offers a reliable method of stabilization while avoiding the morbidity associated with open procedures. In these cases, careful postoperative follow-up remains essential to monitor for signs of physeal disturbance. The patient's age and remaining growth potential should always be factored into surgical decision-making, as younger children carry a higher risk of long-term growth disturbance. Taken together, these principles provide a practical framework for selecting between closed fixation and open reduction in this challenging group of injuries.

4. Conclusion

Periosteal entrapment is an important yet underrecognized factor contributing to failed closed reduction in distal tibial physeal fractures. Although not all cases of periosteal interposition result in growth disturbances, the available clinical and experimental evidence suggests that its presence increases the risk of physeal arrest, particularly in younger patients or in the setting of high-energy trauma. While MRI optimizes diagnosis by allowing preoperative identification of interposed periosteum, its cost and limited accessibility in some settings necessitate further study of alternative modalities such as ultrasound or CT.

Our case supports the role of targeted surgical intervention when anatomical reduction cannot be achieved, as timely removal of the interposed periosteum led to successful healing without deformity or growth arrest. Open reduction should therefore be considered not universally, but selectively, guided by clinical judgment, imaging, and intraoperative findings. Future prospective studies stratifying patients by injury severity and growth potential are needed to establish clearer indications for surgery and optimize long-term outcomes.

Statement of informed consent

The patient was informed that data concerning the case would be submitted for publication, and the patient provided consent.

Consent

Written informed consent was obtained from all subjects (or their legal guardians) involved in the study. The manuscript includes a statement that such consent has been obtained, and a copy is available for review by the Editor-in-Chief upon request.

Consent for publication

Written informed consent for publication of this case report and accompanying images was obtained from the patient's parent/legal guardian, as the patient is under the age of 18.

Ethical approval

The study was conducted with approval from the Ethics Center of Tehran University of Medical Sciences. No specific approval code was assigned for this study. Ethical guidelines have been adhered to, and the study is in compliance with the institution's requirements.

Guarantor

Mohammadmahdi Ebrahiminasab M.D agrees to accept full responsibility for the work and the conduct of the study, has access to the data, and controls the decision to publish.

Research registration number

This study does not qualify as a “First in Man” study and therefore did not require registration.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. No sponsor had any role in the design, execution, interpretation, or writing of the study.

Author contribution

Pouya Tabatabaei Irani, M.D: Conceived and designed the study, led the research team and contributed to manuscript revision.

Hamed Naghizadeh, M.D, AND Elham Poorghasem: Assisted in study design, collected the primary data, and contributed to data analysis.

Taghi Baghdadi^. M.D.: Provided critical revisions that were important for the intellectual content.

Mohammadreza Rezaghof M.D.: Assisted in data collection and analysis.

Mohammad Mahdi Ebrahimi Nasab, M.D.: Coordinated the research efforts, ensured the integrity of the work, and contributed to manuscript preparation and submission.

Conflict of interest statement

All authors declare that there are no financial or personal relationships with other people or organizations that could inappropriately influence their work.