Heterotopic Ossification following Tissue Transfer for Combat-Casualty Complex Periarticular Injuries:

Treatment of Temporomandibular Joint Heterotopic Ossificans: A Novel Protocol With Multimodal Therapy Based on Literature Review and Presentation of a Unique Case Reportc

PURPOSE

The purpose of this study was to create a treatment protocol for cases of heterotopic ossification (HO) of the temporomandibular joint (TMJ), particularly those refractory to current TMJ HO protocols. In addition, we demonstrate the success of this protocol on a unique case of recurrent HO that failed multiple TMJ HO protocols in the setting of an improvised explosive device (IED) blast in a wounded warrior.

METHODS

An electronic literature review was conducted via PubMed and Web of Science. Twenty-five studies were identified to provide supporting evidence for a proposed, up-to-date protocol for the treatment of refractory TMJ HO. The authors present a case report of a wounded warrior with HO ankylosis of bilateral TMJs in the setting of IED blast and demonstrate successful use of our surgical and pharmacotherapeutic protocol.

RESULTS

Based on the literature review, our proposed protocol consists of pharmacotherapy with celecoxib and etidronate, with weekly forced dilation (brisement) and home physical therapy with the TheraBite Jaw Motion Rehab System. Surgically, the TMJ should be treated with two-stage reconstruction using initial polymethyl methacrylate spacers and subsequent total joint reconstruction with custom prostheses, fat grafting, and 3-dimensional-navigated total resection of HO. This protocol was successfully utilized in our patient's refractory HO ankylosed TMJ secondary to IED blast, and the patient's maximal incisal opening was regained and has remained stable 2 years after surgery without recurrent HO.

CONCLUSIONS

Our method for treatment in this case deviated from the standard TMJ Concepts HO protocol in that it included multimodal pharmacotherapy with celecoxib and etidronate. Based on our literature review and experience, we advise that clinicians utilize our protocol for the management of all craniofacial HO cases, particularly in cases of recurrent HO that fail conventional therapies and/or involving high-order blast trauma.

Plastic Surgery at War: A Scoping Review of Current Conflicts

INTRODUCTION

The scope of military plastic surgery and location where care is provided has evolved with each major conflict. To help inform plastic surgeon utilization in future conflicts, we conducted a review of military plastic surgery-related studies to characterize plastic surgeon contributions during recent military operations.

MATERIALS AND METHODS

Using a scoping review design, we searched electronic databases to identify articles published since September 1, 2001 related to military plastic surgery according to a defined search criterion. Next, we screened all abstracts for appropriateness based on pre-established inclusion/exclusion criteria. Finally, we reviewed the remaining full-text articles to describe the nature of care provided and the operational level at which care was delivered.

RESULTS

The final sample included 55 studies with most originating in the United States (54.5%) between 2005 and 2019 and were either retrospective cohort studies (81.8%) or case series (10.9%). The breadth of care included management of significant upper/lower extremity injuries (40%), general reconstructive and wound care (36.4%), and craniofacial surgery (16.4%). Microsurgical reconstruction was a primary focus in 40.0% of published articles. When specified, most care was described at Role 3 (25.5%) or Roles 4/5 facilities (62.8%) with temporizing measures more common at Role 3 and definite reconstruction at Roles 4/5. Several lessons learned were identified that held commonality across plastic surgery domain.

CONCLUSIONS

Plastic surgeons continue to play a critical role in the management of wounded service members, particularly for complex extremity reconstruction, craniofacial trauma, and general expertise on wound management. Future efforts should evaluate mechanisms to maintain these skill sets among military plastic surgeons.

Bioengineered human skeletal muscle capable of functional regeneration

BACKGROUND

Skeletal muscle (SkM) regenerates following injury, replacing damaged tissue with high fidelity. However, in serious injuries, non-regenerative defects leave patients with loss of function, increased re-injury risk and often chronic pain. Progress in treating these non-regenerative defects has been slow, with advances only occurring where a comprehensive understanding of regeneration has been gained. Tissue engineering has allowed the development of bioengineered models of SkM which regenerate following injury to support research in regenerative physiology. To date, however, no studies have utilised human myogenic precursor cells (hMPCs) to closely mimic functional human regenerative physiology.

RESULTS

Here we address some of the difficulties associated with cell number and hMPC mitogenicity using magnetic association cell sorting (MACS), for the marker CD56, and media supplementation with fibroblast growth factor 2 (FGF-2) and B-27 supplement. Cell sorting allowed extended expansion of myogenic cells and supplementation was shown to improve myogenesis within engineered tissues and force generation at maturity. In addition, these engineered human SkM regenerated following barium chloride (BaCl2) injury. Following injury, reductions in function (87.5%) and myotube number (33.3%) were observed, followed by a proliferative phase with increased MyoD+ cells and a subsequent recovery of function and myotube number. An expansion of the Pax7+ cell population was observed across recovery suggesting an ability to generate Pax7+ cells within the tissue, similar to the self-renewal of satellite cells seen in vivo.

CONCLUSIONS

This work outlines an engineered human SkM capable of functional regeneration following injury, built upon an open source system adding to the pre-clinical testing toolbox to improve the understanding of basic regenerative physiology.

Keystone design perforator island flaps for coverage of non-oncological periarticular defects surrounded by the zone of injury

Objective

Periarticular defect coverage remains challenging because multi-vector tension forces affect wound tensile strength. This study presents our experience with keystone design perforator island flap (KDPIF) reconstruction of non-oncological periarticular defects surrounded by the zone of injury and describes the expanding versatility of KDPIF reconstruction for periarticular defects.

Methods

From June 2017 to July 2019, 12 patients aged 8 to 84 years underwent KDPIF reconstruction to cover periarticular defects. All defects resulted from non-oncological causes and were surrounded by the zone of injury. We reviewed the patients’ medical records and clinical photographs to collect and analyze clinical and operative data.

Results

The defect size ranged from 0.8 × 1.2 to 7 × 10 cm². The flap size ranged from 1.5 × 3 to 15 × 18 cm². All flaps survived completely. All patients showed favorable functional outcomes without significant limitation in joint range of motion during the follow-up period (range, 4–12 months). The mean observer scar assessment scale summary score and patient scar assessment scale total score were 17.667 ± 5.921 and 20.167 ± 6.478, respectively.

Conclusion

KDPIF reconstruction is a simple and effective surgical option for coverage of non-oncological periarticular defects surrounded by the zone of injury.

Functional regeneration of tissue engineered skeletal muscle in vitro is dependent on the inclusion of basement membrane proteins

Skeletal muscle has a high regenerative capacity, injuries trigger a regenerative program which restores tissue function to a level indistinguishable to the pre-injury state. However, in some cases where significant trauma occurs, such as injuries seen in military populations, the regenerative process is overwhelmed and cannot restore full function. Limited clinical interventions exist which can be used to promote regeneration and prevent the formation of non-regenerative defects following severe skeletal muscle trauma. Robust and reproducible techniques for modelling complex tissue responses are essential to promote the discovery of effective clinical interventions. Tissue engineering has been highlighted as an alternative method, allowing the generation of three-dimensional in vivo like tissues without laboratory animals. Reducing the requirement for animal models promotes rapid screening of potential clinical interventions, as these models are more easily manipulated, genetically and pharmacologically, and reduce the associated cost and complexity, whilst increasing access to models for laboratories without animal facilities. In this study, an in vitro chemical injury using barium chloride is validated using the C2C12 myoblast cell line, and is shown to selectively remove multinucleated myotubes, whilst retaining a regenerative mononuclear cell population. Monolayer cultures showed limited regenerative capacity, with basement membrane supplementation or extended regenerative time incapable of improving the regenerative response. Conversely tissue engineered skeletal muscles, supplemented with basement membrane proteins, showed full functional regeneration, and a broader in vivo like inflammatory response. This work outlines a freely available and open access methodology to produce a cell line-based tissue engineered model of skeletal muscle regeneration.