Ossification of abdominal scar tissue: a case series with a translational review on its development

Post-laparotomy heterotopic ossification of the xiphoid process: A case report

BACKGROUND

Heterotopic ossification (HO) represents all types of extraskeletal ossification in the body. It occurs in various areas, including the skin, subcutaneous tissue, muscle, and joints. Surgical excision is recommended for symptomatic HO. Postoperative radiotherapy, oral nonsteroidal anti-inflammatory drugs, and topical sealants, such as bone wax, have been recommended as preventive measures. As HO is rare in occurrence, these recommendations are based on personal experiences, and there is a lack of information on individualized treatments depending on its location.

CASE SUMMARY

A 62-year-old male was admitted for symptomatic HO along a laparotomy scar. Surgical excision was performed for an 11 cm-sized ossification originating from the xiphoid process, and bone wax was applied to the excisional margin. However, the surgical wound failed to heal. After several weeks of saline-soaked gauze dressing, delayed wound closure was performed. The patient was finally discharged eight weeks after the excision. Because HO can occur in various areas of the body, a treatment strategy that may be effective for some may not be for others. Bone wax has been used as a topical sealant over excisional margins in the shoulder, elbow, and temporomandibular joints. However, in our case, its application on an abdominal surgical wound delayed its primary healing intention. The valuable lesson was that, when choosing a treatment method for HO based on available research data, its location must be considered.

CONCLUSION

Complete excision should be the priority treatment option for symptomatic HO along the laparotomy scar. Bone wax application is not recommended.

Extensive Heterotopic Ossification in a Large Incisional Ventral Hernia After a Burn Injury Requiring Transversus Abdominis Release

Heterotopic ossification (HO) is an atypical complication of burn injuries presenting in 0.2-4% of cases. Usually, HO develops surrounding long bones or joints after orthopedic procedures or trauma. However, on extremely rare occasions, HO can develop from other bones such as the xiphoid. The purpose of this case report is to describe a case of an open retromuscular abdominal wall reconstruction with bilateral transversus abdominis release (TAR) in a patient with extensive abdominal heterotopic ossification following a midline laparotomy in the setting of a large burn injury. The patient was a 42-year-old man with a history of 55% total burn surface area (TBSA) second- and third-degree flame burns who was treated in a large academic hospital with a renowned burn unit. His case in particular was brought to attention for the rare presentation of the aftermath of a burn injury and the technical surgical challenge it posed. Five months after the last surgical intervention, the patient is doing well without further complications or clinical signs of hernia recurrence. Since there are no established guidelines for patients with HO after burn injuries, learning about alternate strategies will expand the armamentarium of abdominal wall reconstruction surgeons in this challenging patient population. Specifically, retromuscular ventral hernia repair with transversus abdominis release and synthetic mesh can be used in complex ventral hernia repair complicated by heterotopic ossification after a major burn.

Heterotopic ossification beneath the upper abdominal incision after radical gastrectomy: Two case reports

BACKGROUND

Heterotopic ossification (HO) is a rare clinical phenomenon that refers to bone formation in nonossifying tissues.

CASE SUMMARY

This report presents two cases of HO beneath the upper abdominal median incision after radical gastrectomy. The first patient had postoperative pain below the incision area. There were no signs of anastomotic leakage, and the wound healed. Computed tomography (CT) findings 2 wk postoperatively were negative for HO, but the 6-wk CT showed HO beneath the incision. The patient refused reoperation, and after conservative therapy, the pain was gradually relieved after 2 wk. In the second case, postoperative recovery was uneventful, and HO was only detected on routine follow-up CT after 4 mo. An anti-adhesion membrane was applied beneath the peritoneum in both patients. Our findings suggest that HO beneath the abdominal incision might form at approximately 1 mo postoperatively. It may cause intractable pain; however, reoperation is usually not required.

CONCLUSION

In our cases, we suspect that HO may be related to the use of foreign materials beneath the peritoneum, which needs to be further investigated.

Sustained local ionic homeostatic imbalance caused by calcification modulates inflammation to trigger heterotopic ossification

Heterotopic ossification (HO) is a condition triggered by an injury leading to the formation of mature lamellar bone in extraskeletal soft tissues. Despite being a frequent complication of orthopedic and trauma surgery, brain and spinal injury, the etiology of HO is poorly understood. The aim of this study is to evaluate the hypothesis that a sustained local ionic homeostatic imbalance (SLIHI) created by mineral formation during tissue calcification modulates inflammation to trigger HO. This evaluation also considers the role SLIHI could play for the design of cell-free, drug-free osteoinductive bone graft substitutes. The evaluation contains five main sections. The first section defines relevant concepts in the context of HO and provides a summary of proposed causes of HO. The second section starts with a detailed analysis of the occurrence and involvement of calcification in HO. It is followed by an explanation of the causes of calcification and its consequences. This allows to speculate on the potential chemical modulators of inflammation and triggers of HO. The end of this second section is devoted to in vitro mineralization tests used to predict the ectopic potential of materials. The third section reviews the biological cascade of events occurring during pathological and material-induced HO, and attempts to propose a quantitative timeline of HO formation. The fourth section looks at potential ways to control HO formation, either acting on SLIHI or on inflammation. Chemical, physical, and drug-based approaches are considered. Finally, the evaluation finishes with a critical assessment of the definition of osteoinduction. STATEMENT OF SIGNIFICANCE: The ability to regenerate bone in a spatially controlled and reproducible manner is an essential prerequisite for the treatment of large bone defects. As such, understanding the mechanism leading to heterotopic ossification (HO), a condition triggered by an injury leading to the formation of mature lamellar bone in extraskeletal soft tissues, would be very useful. Unfortunately, the mechanism(s) behind HO is(are) poorly understood. The present study reviews the literature on HO and based on it, proposes that HO can be caused by a combination of inflammation and calcification. This mechanism helps to better understand current strategies to prevent and treat HO. It also shows new opportunities to improve the treatment of bone defects in orthopedic and dental procedures.

Incidence and factors associated with development of heterotopic ossification after damage control laparotomy

INTRODUCTION

The incidence of heterotopic ossification (HO) following damage control laparotomy (DCL) is unknown. Abdominal wall reconstruction may prove more challenging in patients with HO. This study examines the incidence and factors associated with HO in patients with an open abdomen following DCL.

METHODS

A retrospective review of all patients with an open abdomen after DCL at a level 1 trauma centre from 2009 to 2015 was conducted. Demographics and peri-operative outcomes of patients with and without HO were compared. Univariate and multivariable binary logistic regression models were used to determine the association of peri-operative factors with the development of HO.

RESULTS

68 patients were included, of which 36 (53%) developed HO. On univariate analysis, development of HO was significantly associated with hollow viscus injury (OR, 3.89; CI 1.42-10.7), greater number of abdominal surgeries prior to definitive closure (OR, 1.84; CI, 1.10-3.05), non-fascial closure (OR, 4.33; CI, 1.44-13.1) and higher peak ALP (OR 1.01; CI, 1.00-1.02). The presence of a hollow viscus injury remained an independent predictor of HO on multivariable analysis after adjusting for covariates (OR, 3.77; CI, 1.22-11.6).

CONCLUSION

Heterotopic ossification develops in a high proportion of trauma patients following damage control laparotomy, particularly in the presence of hollow viscus injury. Its impact on delayed abdominal wall reconstruction and the efficacy of prophylaxis strategies merit further investigation.

Extensive Abdominal Wall Incisional Heterotopic Ossification Reconstructed with Component Separation and Strattice Inlay

Symptomatic heterotopic ossification of abdominal surgical incisions is a rare occurrence. We present a 67-year-old man with severe discomfort caused by heterotopic ossification extending from the xiphoid to the umbilicus. The patient underwent an abdominal aortic aneurysm repair 3 years before our treatment. A 13 × 3.5 cm ossified lesion was excised. The resulting midline defect was closed using component separation and inlay Strattice. Tension-free midline adaptation of the recti muscles was achieved. A computed tomography scan of the abdomen 6 months after the surgery showed no recurrence or hernias. Heterotopic ossification in symptomatic patients has previously been treated with excision and primary closure. We believe that tension-free repair is important to prevent recurrence. Acellular dermal matrix may add to this effect and also compartmentalize the process.