The Role and Efficacy of NovoSorb Biodegradable Temporizing Matrix in Complex Reconstructive Wounds: A Systematic Review

Abstract

Background:

Managing complex wounds with exposed bone, tendons, metalware, or irradiated tissue is challenging. NovoSorb Biodegradable Temporizing Matrix (BTM) offers an alternative by promoting vascularization and neodermis formation. This review assessed the effectiveness of BTM in managing complex wounds, including those with vascular compromise (eg, periosteal stripping or denuded paratenon) or exposure to radiotherapy.

Methods:

A systematic search of Embase, Ovid, Scopus, and PubMed was conducted. Inclusion criteria included wounds involving exposed bone, tendons, or radiotherapy exposure. Data were analyzed for clinical outcomes, demographic variables, and complications.

Results:

A total of 208 patients across 34 studies were analyzed. The overall complication rate was 27.9%. Wounds with combined bone and tendon exposure and periosteal stripping or denuded paratenon had significantly higher complication rates than those with only exposed bone and tendon (57.1% versus 35.3%, P = 0.006). Denuded tendons only had significantly higher complication rates compared with intact tendons (38.9% versus 18.6%, P = 0.044). Across all wounds, the presence of periosteal stripping and/or denuded paratenon was linked to significantly more complications (40.0% versus 21.8%, P = 0.005). Chronic wounds were independently associated with a 4-fold increase in complication risk (P = 0.013). Upper extremity wounds had significantly lower complication rates than lower extremity wounds (odds ratio 0.295, P = 0.008). Increasing age was independently associated with poorer outcomes (odds ratio 1.015 per year, P = 0.039).

Conclusions:

BTM is a valuable addition to the reconstructive armamentarium. However, complication rates in complex wounds are high, so careful clinical judgment is essential for their implementation.

Takeaways

Question: What are the effectiveness and complication rates of NovoSorb Biodegradable Temporizing Matrix in managing complex wounds with exposed bone, exposed tendon, or irradiated tissue?

Findings: A systematic review of 208 patients across 34 studies showed a 27.9% overall complication rate, with significantly higher rates in wounds involving periosteal stripping or denuded tendons, chronic wounds, lower extremity sites, and increasing patient age.

Meaning: Although Biodegradable Temporizing Matrix is a valuable tool in complex wound reconstruction, its use, especially in biologically compromised wound beds, requires cautious, individualized clinical judgment due to high complication rates.

INTRODUCTION

Management of complex soft tissue defects remains a significant challenge in reconstructive surgery. Exposure of bone with or without periosteal stripping,¹ exposure of tendons with or without paratenon, and exposure to radiation therapy² all reduce the success of conventional grafts and local/regional flaps.^3,4 Although these approaches may achieve wound closure and restore form and function, they may be associated with limited donor site availability, donor site morbidity, longer operative times, and inconsistent aesthetic outcomes.^5–7

Dermal substitutes such as NovoSorb Biodegradable Temporizing Matrix (BTM, PolyNovo Biomaterials Pty Ltd, Port Melbourne, Victoria, Australia) provide a relatively novel option in reconstructive wound management. BTM is a fully synthetic, bilayer polyurethane dermal substitute consisting of a biodegradable open-cell foam matrix. The foam layer is intended to serve as a scaffold that permits cellular infiltration, vascularization, and collagen deposition.^8–12 At the same time, the sealing membrane is designed to function as a temporary epidermal barrier, limiting fluid loss, contamination, and contraction.^8,9,12 The absence of biologic components reduces the potential for immunogenic reactions and infection and avoids issues associated with animal-derived products.^13,14 Comparative studies have also reported that BTM demonstrates resistance to early delamination and can provide acceptable aesthetic and functional outcomes relative to certain biologic substitutes, such as Integra.^8,15

Since its introduction, the clinical utility of BTM has expanded beyond burn¹⁶ injuries to encompass necrotizing soft tissue infections, trauma-induced defects, and oncological resections.^17–26 Published reports, largely case studies or small retrospective series, have demonstrated the feasibility of BTM in various wound beds, including exposed bone, tendon, and neurovascular structures,^27–30 as well as in severely compromised scenarios involving bone with periosteal stripping, tendons denuded of paratenon, underlying metal implants, or radiotherapy-affected tissue.^31–38 However, these sporadic and observational accounts underscore the need for a more comprehensive evaluation of its efficacy and limitations in complex settings, prompting the current systematic review. This study aimed to systematically review and determine the efficacy of NovoSorb BTM in patients presenting with complex wounds with exposed bone (with and without periosteal stripping), exposed fracture, exposed tendons (denuded of paratenon and nondenuded), underlying metal prostheses, and/or radiation exposure.

METHODS

Search Strategy and Data Sources

A systematic search of Embase, Ovid, MEDLINE, Scopus, and PubMed databases was conducted in August 2024 using predetermined search terms (Biodegradable Temporising Matrix, Biodegradable Temporizing Matrix, BTM, and Biodegradable polyurethane). Both Australian and American spellings were included, and no geographic restrictions were applied. Reference lists of all eligible articles and relevant reviews were screened to identify additional studies not captured by the initial database searches. This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was prospectively registered on the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42024535839).

Using Covidence, 2 independent reviewers (O.H.S. and S.P.) screened titles and abstracts to determine eligibility, resolving any discrepancies through discussion or involving a third reviewer (B.N.A.) if necessary. Methodological quality and risk of bias were assessed using the relevant Joanna Briggs Institute (JBI) critical appraisal tool. (See table, Supplemental Digital Content 1, which displays a methodological quality assessment of included studies using the JBI Critical Appraisal Checklist for [A] case series and [B] case reports. Each criterion is scored as “yes,” “no,” “unclear,” or “not applicable,” with higher numbers of “yes” responses indicating better methodological quality, https://links.lww.com/PRSGO/E626.)

Inclusion and Exclusion Criteria

Clinical studies were included if they reported on the use of BTM in human patients with complex wounds involving at least one of the following:

• exposed bone,

• exposed bone with periosteal stripping,

• exposed tendon,

• exposed tendon denuded of paratenon,

• exposed fracture site,

• exposed metal prostheses,

• wounds exposed to radiation therapy (either before or after BTM application).

Subgroup analysis focused on wounds with periosteal stripping or denuded tendon, and cases involving nondenuded periosteum and paratenon were also included as pseudo-controls. This approach allowed for comparative analysis to assess potential differences in outcomes.

No restrictions were imposed on age, sex, or ethnicity. There were no restrictions on the anatomical site of the wound. Exclusion criteria included unpublished data, systematic reviews, meta-analyses, editorials, discussions, commentaries, abstracts, animal studies, and letters. Clinical studies that failed to report any primary outcomes or meet at least one of the abovementioned criteria were also excluded.

Data Collection and Analysis

Data were collected by 2 reviewers (O.H.S. and S.P.) and included patient demographics (age, sex), wound etiology (trauma, burns, or malignancy), anatomical location (head and neck, trunk, or upper/lower extremity), wound bed features (meeting inclusion criteria), details of BTM application (time to skin graft), and duration of follow‐up. Outcome parameters included time to BTM integration (d), postoperative complications (including infection, BTM nonadherence or failure, skin graft failure), and hospital length of stay.

Given the heterogeneity of study designs and the absence of internal control groups within most included studies, a formal meta-analysis was not feasible. Instead, a pooled descriptive analysis was performed. Statistical comparisons should be interpreted in the context of observational heterogeneity.

Univariate logistical regression was used to evaluate the association between complication rates and age, wound bed structures, wound etiology, and wound location. Odds ratios (ORs) with 95% confidence intervals were calculated to quantify effect sizes, with statistical significance set at a P value of less than 0.05. A separate multivariate logistic regression analysis was performed, adjusting for age as a key confounding variable. This adjusted model specifically assessed the impact of wound characteristics, including periosteal stripping, denuded tendon, and prior radiotherapy exposure, on surgical outcomes. The coefficient values from these models were used to interpret the likelihood of complications for each predictor.

RESULTS

A total of 301 references were identified from database searches (see Fig. 1). From these, 161 duplicates were identified and removed, leaving 140 studies for title and abstract screening. Following this process, 62 studies were excluded as they did not meet the inclusion criteria. The remaining 78 studies underwent full-text review, from which 44 studies were further excluded. In total, 34 studies were included in the final analysis, comprising case reports (n = 16), case series (n = 12), retrospective studies (n = 5), and prospective studies (n = 1), accounting for 208 cases with a median age of 58.5 years. (See table, Supplemental Digital Content 2, which displays a summary of 34 studies included in the analysis, https://links.lww.com/PRSGO/E627.) The years of publication ranged from 2016 to 2024, with a noticeable increase in publications in 2022 (5 publications), 2023 (8 publications), and 2024 (8 publications), suggesting growing interest in BTM and a potential expansion of its indications. Geographically, the studies were primarily based in Australia (n = 15) and Europe (n = 13), with North America (n = 4) and Asia (n = 2) contributing more recent publications, likely associated with regulatory approvals such as the CE Mark and the Food and Drug Administration in Europe and the United States, respectively.

Fig. 1.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses flowchart of included studies. Thirty-four studies were included in the final analysis. **Records excluded during title and abstract screening for failure to meet predefined inclusion criteria, including population, study type, or language.

A total of 208 patients were included in the study, with a median age of 58.5 years (interquartile range: 37–73 y) (Table 1). The most common wound etiologies were trauma (28.4%) and malignancy (19.7%). The lower extremities were the most frequently affected anatomical site (49.0%). The overall complication rate was 27.9%, with BTM loss and infection accounting for the majority of adverse outcomes.

Table 1.

Summary of Patient Demographics, Wound Characteristics, Median Time to BTM Integration, and Postoperative Complications for the Total of 208 Patients Included in the Analysis

Total no. patients	208
Median age, y (IQR)	58.5 (37–73)
Sex	n (%)
Male	73 (35.1)
Female	32 (15.4)
Not reported	103 (49.5)
Wound etiology
Trauma	59 (28.4)
Malignancy	41 (19.7)
Burns	35 (16.8)
Infection	22 (10.6)
Chronic	19 (9.1)
Iatrogenic	16 (7.7)
Not reported	16 (7.7)
Anatomical location
Lower extremity	102 (49.0)
Upper extremity	49 (23.6)
Head and neck	35 (16.8)
Trunk	6 (2.9)
Not reported	16 (7.7)
Median time to BTM integration	Days (IQR)
All reported cases	41 (33–49.5)
Cases with complications	45.0 (35.0–54.0)
Cases without complications	38.5 (32.0–47.0)
Postoperative complications	% (n)
No complication	72.1 (150)
Complications	27.9 (58)
BTM loss	32.8 (19)
Infection	25.8 (15)
Graft loss	15.5 (9)
Miscellaneous	13.8 (8)
Hematoma	8.6 (5)
Tendon adhesions	3.4 (2)

IQR, interquartile range.

The median time for BTM integration was 41 days (interquartile range: 33–49.5 d). Patients who developed complications experienced longer integration times (45 versus 38.5 d) (P = 0.097). Notably, the age-stratified analysis highlighted an increasing trend of complications with advancing age, ranging from 12.5% in pediatric/young adult patients (0–18 y) to 32.4% in much older patients (>81 y of age). The OR of 1.015 (95% confidence interval: 1.001–1.030) indicated that each additional year of age increased the odds of complications by 1.52% (P = 0.039) (Table 2).

Table 2.

Univariate Logistic Regression Analysis Examining the Role of Age, Wound Etiology, and Anatomical Location on BTM Complication Rates

Predictor	OR (95% CI)	Coefficient (Log-Odds)	Standard Error	P
Age (per year increase)	1.015 (1.001–1.030)	0.015	0.007	0.039
Wound etiology
Trauma (reference)	1.0	0	—	—
Burns	1.314 (0.513–3.308)	0.273	0.472	0.562
Chronic	3.942 (1.351–12.057)	1.372	0.553	0.013
Iatrogenic	0.662 (0.138–2.409)	−0.413	0.707	0.559
Infection	1.075 (0.336–3.167)	0.072	0.565	0.898
Malignancy	0.956 (0.370–2.395)	−0.046	0.473	0.923
Anatomical location
Lower extremity (reference)	1.0	0	—	—
Head and neck	0.599 (0.243–1.376)	−0.512	0.438	0.242
Trunk	1.730 (0.307–9.766)	0.548	0.842	0.515
Upper extremity	0.295 (0.112–0.690)	−1.219	0.458	0.008

Bold values indicate statistical significance (P < 0.05).

CI, confidence interval.

Among wound etiologies, chronic wounds were the only category significantly associated with increased complications, demonstrating nearly a 4-fold increase in odds compared with trauma (OR 3.942, P = 0.013) (Table 2). Other etiologies, including burns, iatrogenic wounds, infection, and malignancy, did not show statistically significant associations with complication rates.

Anatomical location also influenced outcomes. Compared with lower extremity wounds, upper extremity wounds were associated with a 70% reduction in complication odds (OR 0.295, P = 0.008). In contrast, wounds located on the head and neck or trunk did not significantly differ from lower extremity wounds in terms of complication risk. In this logistic regression, trauma etiology and lower extremity location were used as reference categories, as they represented the largest subgroups and provided the most statistically stable and clinically appropriate baseline for comparison.

The overall complication rate among the 208 cases included was 27.9% (58 of 208) (Table 3). Complication rates varied according to wound bed characteristics. The highest complication rate was found in wounds exposed to radiation therapy, 60.0% (6 of 10). Notably, in cases with combined bone and tendon exposure (n = 31) with periosteal stripping/denuded tendon, the complication rate was 57.1% (8 of 14). When grouping all cases involving exposed bone, tendon, or both, subgroup analysis showed a complication rate of 40.0% (26 of 65) when periosteal stripping or tendon denudation was present, compared with 21.0% (25 of 119) in intact cases. Finally, the complication rate in wounds overlying exposed fracture sites was 0.0% (0 of 10), and in those involving exposed metal prostheses was 25.0% (1 of 4) (Table 3). Unfortunately, given the small sample size for metal prostheses and the absence of complications in fracture-site cases, these subgroups were not included in the multivariate logistic regression analysis.

Table 3.

Wound Characteristics and Complication Rates

Wound characteristics	No. Cases, %	Cases With Complications in Each Group, %
All cases	208	58 (27.9)
Exposed bone only	76	19 (25.0)
Bone with periosteal stripping	33 (15.9)	11 (33.3)
Without periosteal stripping	43 (20.7)	8 (18.6)
Exposed tendon only	77	18 (23.3)
Tendon denuded	18 (8.7)	7 (38.9)
Tendon not denuded	59 (28.4)	11 (18.6)
Exposed bone and tendon	31	14 (45.2)
With periosteal stripping/denuded tendon	14 (6.7)	8 (57.1)
Without periosteal stripping/denuded tendon	17 (8.2)	6 (35.3)
Exposed bone + exposed tendon + exposed bone and tendon	184	51 (27.7)
With periosteal stripping/denuded tendon	65	26 (40.0)
Without periosteal stripping/denuded tendon	119	25 (21.0)
Wounds exposed to radiation therapy	10 (4.8)	6 (60.0)
Exposed fracture site	10 (4.8)	0 (0.0)
Exposed metal prosthesis	4 (1.9)	1 (25.0)

Multivariate logistic regression further emphasized the increased risk associated with periosteal stripping and denuded tendons. In cases with both bone and tendon exposure, the presence of periosteal stripping and/or denuded tendon was associated with a significantly higher complication rate (57.1% versus 35.3%, P = 0.006), compared with intact exposed bone and tendon (Table 4).

Table 4.

Multivariate Logistic Regression (Adjusting for Age) Analysis of Complication Rates Among 208 Cases According to Wound Bed Characteristics

Baseline Group	Predictor	OR (95% CI)	Coefficient (Log-Odds)	Standard Error	P
Bone + tendon + bone and tendon	Periosteal stripping + denuded tendon	2.61 (1.32–5.15)	0.959	0.346	0.005
Bone	Periosteal stripping	1.95 (0.68–5.59)	0.667	0.537	0.215
Tendon	Denuded tendon	3.57 (1.04–12.32)	1.273	0.631	0.044
Bone and tendon	Periosteal stripping/denuded tendon	5.18 (1.61–16.63)	1.645	0.563	0.006
Bone	Radiotherapy	4.60 (0.97–21.68)	1.526	0.791	0.053

Bold values indicate statistical significance (P < 0.05).

P values indicate the statistical significance of differences in complication rates between different subgroups.

CI, confidence interval.

In the exposed tendon group, denuded tendons resulted in a significantly higher complication rate (38.9% versus 18.6%, P = 0.044) compared with intact tendons. When considering all cases involving bone and/or tendon exposure (excluding fractures, metalware, and radiotherapy cases), the presence of periosteal stripping and/or denuded tendons significantly increased complication rates, nearly doubling the rate (40.0% versus 21.0%, P = 0.005). Despite radiotherapy-exposed wounds having the highest complication rates, this only approached statistical significance (P = 0.053) (Table 4). These results suggest that age, periosteal stripping, and denuded tendons can significantly impact the likelihood of complication rates and surgical success, particularly in wounds involving both bone and tendon.

DISCUSSION

The expanding global adoption of BTM beyond burns to other indications, including trauma, malignancy, and necrotizing fasciitis, reflects increasing confidence in its versatility.^{8,27,29,39–46} This trend showcases a broader movement toward less invasive techniques that minimize donor site morbidity and surgical times, particularly in patient groups where major surgery may not be viable. In this study cohort, however, 57% of wounds had theoretically graftable beds, including bone with preserved periosteum or tendon with intact paratenon, prompting reflection on whether BTM use in these settings conferred a meaningful advantage. Advocates of BTM report purported benefits such as improved scar quality with its use.⁴⁷ However, the lack of long-term comparative data regarding scar quality necessitates caution in its use if simpler options exist (including direct split skin grafting). BTM’s versatility must be carefully contextualized against other factors, such as the associated risk of complications, delay in wound closure, and cost.

The overall complication rate of 27.9% in this series underscores the complexity of some of these cases. When all bone, tendon, and bone and tendon exposures were grouped together, the presence of periosteal stripping and denuded tendon was associated with a significantly increased risk of complications (40.0% versus 21.0%, P = 0.005) (Table 4). Among these, wounds with both periosteal stripping and denuded tendons had the highest complication rate, reaching 57.1% (P = 0.006), and wounds with exposed tendon devoid of paratenon were also associated with an increased risk of complications (38.9%, P = 0.044) (Tables 3, 4). Radiotherapy-exposed wounds exhibited a notably higher complication rate (P = 0.053), aligning with the well-documented effects of radiation-induced fibrosis and chronic inflammation on wound healing.^48–50 These subgroup analyses highlight the importance of clinician judgment and the limitations of BTM.

In addition to wound bed exposure, other factors such as wound etiology, anatomical location, and patient age should also be considered. Regarding wound etiology, chronic wounds were shown to have a significantly higher risk of complications (OR = 3.942, P = 0.013) (Table 2). This aligns with findings from previous studies, which emphasize that chronic wounds, characterized by a prolonged inflammatory phase and impaired cellular function, are more susceptible to fluid loss and infections, resulting in increased rates of complications.^51,52 The anatomical location also contributed to BTM complications, with the upper extremity demonstrating a markedly lower risk than the lower extremity (OR = 0.295, P = 0.008). The generally better vascular supply in the upper extremities and reduced exposure to weight-bearing and mechanical stress compared with the lower extremities may facilitate more effective BTM integration and lead to fewer complications.^53,54 Furthermore, venous stasis and impaired outflow in the lower extremity are potential contributors to delayed wound healing. They may account for the higher complication rates observed at this anatomical site, as poor venous return can compromise the integration of dermal substitutes.

An age-related increase in complication rates was also observed, with each additional year increasing the odds of complications by 1.52% (P = 0.039), aligning with existing literature highlighting the diminished regenerative capacity in older patients.^55–57 Physiologically, this can be attributed to reduced vascularity, decreased cellular proliferation, and a higher prevalence of comorbidities that impair wound healing.^58,59 Conversely, pediatric patients demonstrated markedly better outcomes, consistent with their superior healing responses.^60–62 These findings underscore a critical limitation of BTM: it may work less effectively in the very cohort that would benefit most from it, including older and frail patients.

The median time for BTM integration was 41 days, which falls within the reported BTM integration range of 28–83 days.^17,63,64 Beyond biologic considerations, delayed closure has significant cost implications. At our institution, 5 cm² of BTM costs approximately A$877 (~US $550). Beyond the material cost, the indirect expenses—including prolonged hospital stays, dressing requirements, medical and nursing reviews, and loss of patient productivity—can be substantial. In Australia, the average cost of an inpatient hospital bed ranges from A$2500–A$3700 per night (~US $1650–$2450),⁶⁵ and although patients treated with BTM do not routinely remain hospitalized for the full integration period, hospital stays may be prolonged in cases with a high risk of complications, further increasing treatment costs. Therefore, the cumulative financial burden of treatment should represent a significant consideration in clinical decision-making. BTM should be used judiciously, ensuring that its advantages outweigh the potential downsides of delayed wound closure. In cases where alternative methods can achieve prompt closure, consideration is warranted.

Although BTM has shown promise, the predominance of infection (15 of 58, 25.8%) as a complication emphasizes the importance of stringent perioperative management, particularly as a result of the well-documented role of infection in autologous graft failure.⁶⁶ Therefore, infection prevention strategies—including prophylactic antibiotics, meticulous surgical techniques, and aggressive postoperative monitoring—remain essential for reducing the risk of complications.^67,68 Future research may consider incorporating antimicrobial agents directly into BTM to lower infection rates. For example, studies may explore incorporating silver nanoparticles with BTM to deliver localized, sustained antimicrobial activity, potentially reducing postoperative infection rates. Additionally, applying negative pressure wound therapy in conjunction with BTM may promote granulation tissue formation, reduce bacterial load, and remove exudate, thus reducing the risk of infection.⁶⁹

This study has several limitations. First, the pooled data primarily derive from observational studies, including retrospective case series and case reports, rather than from randomized controlled trials. This limits the ability to infer causality and adequately control for confounding variables. Second, the small number of cases in certain subgroups, such as wounds involving exposed fractures, metal prostheses, or prior radiotherapy exposure, reduces the statistical power to detect meaningful differences, potentially leading to an overestimation or underestimation of true complication rates. Third, the heterogeneity of the included studies, encompassing diverse wound etiologies, anatomical locations, and surgical techniques, introduces variability that may not be fully accounted for in the analyses. Fourth, a lack of uniform reporting on key variables, such as detailed comorbidity profiles, wound surface area, the extent of bone or tendon exposure, and specific perioperative protocols, limits interpretation and could obscure critical patient- or technique-related factors influencing outcomes. This is particularly relevant because autologous split-thickness skin grafts may successfully bridge small avascular defects without necessitating BTM. Additionally, the general tendency in the literature to underreport negative outcomes likely inflates perceived success rates and underestimates complication frequencies. Finally, although creating a pseudo-control cohort, such as comparisons between denuded and nondenuded structures, offers a useful internal benchmark, it remains an observational comparison rather than a rigorously matched control, thereby limiting the strength of conclusions regarding causation.

CONCLUSIONS

The findings of this study highlight the complex interplay among anatomical location, wound characteristics, and patient demographics in influencing outcomes following BTM application. BTM performed well across a wide range of etiologies and anatomical locations, with upper extremity wounds showing particularly favorable outcomes. The fully synthetic composition minimizes immunogenicity and infection risk compared with biologic substitutes, while offering reliable scaffold formation and stable coverage in settings such as trauma, malignancy, and chronic wounds. Although BTM offers promising reconstructive possibilities, particularly for patients unsuitable for extensive surgical interventions, careful patient selection, meticulous surgical planning, and robust postoperative care are essential to optimize outcomes. The increased risks associated with denuded tendon, periosteal stripping, and radiotherapy exposure further underscore the need for caution, especially in older patients who present additional physiological challenges.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.