Keywords
ankle - reconstruction - biomaterials - fractures
Introduction
The treatment of fractures could be a challenge for surgeon especially when loss of bone, ligament, and/or tendon tissue occur. In the few past years the use of regenerative medicine approaches in these clinical conditions is increasing for their reconstructive/regenerative ability. To date, several biological materials are distributed by tissue banks for tissue reconstruction. In particular, the biological effectiveness of the skeletal muscle tissue and its derivatives depend on their ability to promote osteogenic, osteoinductive, and osteoconductive properties.[1]
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[4] Other biological materials frequently used alone as reconstructive/regenerative solution in different clinical conditions are the biological, cell-free matrices obtained from decellularization of dermis in which the structural integrity remains unaltered.[5] The platelet-rich plasma (PRP), in prevalence autologous, is also frequently used to enhance the regenerative action and the healing process on the lesion area.
The purpose of this study was the use for the first time of these three biological materials combined together as an innovative approach for the treatment of the same, not repairable lesion.
Case Report
A 38-year-old female patient showed at X-ray a pluriframmentary medial malleolus of the ankle and fractures to the omolateral ileo and ischio pubic branches due to an incident that occurred 8 months before our observation ([Fig. 1A]). The injury was conservatively treated with a nonweight-bearing plaster boot for 30 days. After this period, the patient showed dry ankle, no pain, and no limitation in movement, and as a result functional rehabilitation was prescribed. During convalescence, the patient complained about constant pain, impossibility to weight-bearing, fixed foot in pronation, severe ankle limitation, and intense pain at the medial retromalleolar district palpation. The ankle appeared progressively more swollen especially on the medial segment and tests to assess the ankle and subtalar laxity were not performed due to intense pain. Computerized tomography (CT) scans of the ankle highlighted a “cystic-like” area with loss of bone tissue without an apparent containment wall at the level of the posterior part of the medial malleolus and the presence of numerous perimalleolar, probably mobile, bone fragments ([Fig. 1B]). Thus, surgical indication was considered and reconstructive/regenerative procedures were chosen to treat bone loss, deltoid ligament injuries, and “pain” in the retromalleolar aspect of the ankle. To have a direct view of the medial compartment of the right ankle, the patient was placed in supine decubitus, with an ipsilateral hip extra rotated and with the knee flexed. Moreover, we applied a tourniquet at the root of the limb, while the contralateral limb was raised and sustained by a special support. Then, we performed a posterior medial incision of the skin, arched on the malleolus that was extended distally to the spring ligament complex and reached the bone plane, the ligament, and the posterior tibial tendon ([Fig. 2A]). As a first step, we evaluated and treated the bone lesion: no solution of cortical was evident so that the cystic cavity, found on CT, was delimited by a continuous bone cortex but of reduced thickness and therefore easily penetrable by a series of needles that were used to “delimit” the perimeter. We then exposed the cystic cavity with an osteotome. Then, we filled the lesion area with the morselized bone allograft augmented with homologous PRP ([Fig. 2B]). The portion of peripheral cortical was recomposed and stabilized with two titanium screws 1.7 mm in diameter ([Fig. 2C]). After that, we removed mobile and large perimalleolar bone fragments and, as a consequence, portions of ligament tissue. Then, the gap was quantified, without possibility of repair. We have therefore decided to rebuild the anteroinferior portion of the deltoid ligament using decellularized human dermal matrix (DHDM), 5 × 5 cm in dimensions, that is produced by Emilia Romagna Regional Skin Bank through the application of a patented method of decellularization (PTC/IB2008/002753).[5] DHDM was sutured distally and marginally “side-to-side” to the ligamentous residue, while the remaining portion of it was sutured to the periost of the malleolus that was left intact proximally ([Fig. 3A–C]). The DHDM under tension was then infiltrated with homologous PRP using an insulin needle. Then, we quantified the lesion of the posterior tibial tendon that showed a severe fibrillar structural alteration without loss of continuity. After the removal of the degenerated tendon tissue, we performed a tubulization wrapping the degenerated tendon with DHDM ([Fig. 4A, B]), so that a “sealed” chamber around the tendon could be created and PRP was injected inside it ([Fig. 4C]). The ankle was immobilized with a 90-degree walker and weight-bearing was proscribed for approximately 35 days. After 15 days, a passive range of motion (ROM) was guaranteed by continuous passive motion of the ankle only in flexion-extension. After 35 days the patient started a program of articular and neuro- and myo-functional re-education. The clinical follow-up was then performed after 6 months. The magnetic resonance images (MRIs) showed a deltoid ligament and a posterior tibial tendon defined as normal ([Fig. 5B], [D], yellow arrows). Moreover, the cystic bone bladder cavity was no longer evident. The patient recovered well, ankle was stable with normal function. To better identify the quality of the remodeled tissue, we performed an MRI with contrast after 9 months from intervention, since a biopsy sampling was not possible. The clinical results showed a signal compatible with vascularization (red arrow) of the tissue which is considered normal in the previous MRI without any sign of degeneration (yellow arrow) ([Fig. 5A], [C], red arrows).
Fig. 1 (A) X-ray of the right ankle. Fracture of the medial malleolus. (B) Computerized tomography (CT) scans: “Cystic-like” lesion of the medial malleolus and bone fragments.
Fig. 2 (A) Open “cystic-like” medial malleolus. (B) Morselized bone allograft. (C) Closure of the cavity after boring.
Fig. 3 (A) Decellularized human dermal matrix (DHDM). (B, C) DHDM sutured.
Fig. 4 (A) Posterior tibial tendon antomo-pathologic condition. (B) Decellularized human dermal matrix (DHDM) application around lesion. (C) Platelet-rich plasma (PRP) injection.
Fig. 5 Magnetic resonance imaging (MRI) with (A, C) or without (B, D) contrast intravenous at 6 and 9 months.
Discussion
In the last couple of years interest is increasing in the use of biological materials for the treatment of different clinical conditions, to take advantage of their regenerative potential. In particular, the use of bone tissue is widely useful in orthopaedics for the maintenance of its osteogenic, osteoinductive, and osteoconductive properties that makes it a suitable candidate to treat different orthopaedic conditions.[1]
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[4] Among the biological materials, the acellular dermal matrices are also particularly effective as biological cell-free scaffolds as they are currently widely used in different clinical fields for tissue reconstruction.[6] For their effectiveness, biological materials are processed and distributed by tissue banks that are specific for different type of tissues. The autologous/homologous PRP as well as the mesenchymal cells derived from bone or adipose tissue are also frequently used in regenerative medicine.[7] In particular, the high regenerative potential of homologous PRP distributed by transfusion service is suitable to enhance the healing process on the lesion area so that it is frequently used to induce regeneration.[8]
[9] The clinical application of a single regenerative material as well as its use in combination with PRP was previously described in the literature.[10]
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[19] However, the level of evidence of published scientific works is not yet consistently high, so reported good clinical results are still of questionable statistical significance. In orthopaedics, the possible application of biological materials are numerous and topographically varied with the main purpose of solving problems of substance loss or tissue degeneration. Thus, an increase of scientific production about their use could be very helpful to improve treatments in this field.
With the aim to contribute with our experience to emphasize the effectiveness of biological materials in orthopaedics, here we reported results of a clinical case treated with three different biological materials in which loss of bone, ligament, and degenerative tendon tissue occur. To our knowledge, it is the first time that three different biological materials are combined together for the same patient appearing to be an innovative approach for the treatment of the same, not repairable lesion. In particular, we obtain morselized bone tissue by musculoskeletal tissue bank of Rizzoli Orthopedic Institute that has high expertise in the production of bone tissue for orthopaedic purposes. Moreover, we also used acellular dermal matrix developed and distributed by Emilia Romagna Regional Skin Bank of the AUSL Romagna. In particular, the skin tissue bank developed a patented decellularization method that is applied on human dermis to produce a dermal cell-free scaffold that previously showed excellent results in different clinical fields.[20]
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[24] In fact, the ability of DHDM to maintain a balance between structural integrity and the removal of cellular component makes it suitable for different type of tissue reconstruction. Thus, we decided to use the DHDM since it is able to mimic the structural and biological characteristics of tendons avoiding problems deriving from rejection. The PRP obtained by transfusion service of the AUSL Romagna was also used to give value to our treatment and to further promote the effectiveness of both biological materials and, in turn, the healing process. Although its use is still debated in literature, its effectiveness on bone tissue regeneration was previously described.[13]
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[17] Our clinical result was optimal considering that the patient has recovered the full ROM of the ankle joint, does not feel pain even after long periods of standing up for work, and does not report instability of the ankle and subtalar joints. Moreover, she can do any activity and reports improvements in her quality of life. From an instrumental point of view, the MRI with contrast medium has identified an optimal and “viable” regeneration of bone, tendon, and ligament structures. Thus, this case report show, even if not in a significant way, that the knowledge of the regenerative potential of different biological materials can determine the technical and surgical choices that are unique and also of high practical value. However, we have to consider that a potential drawback of the technique is the unpredictable evolution of the regeneration process. In fact, an evolution toward fibrosis instead of a finalistic anatomical recovery of the treated structures could have created the conditions for a rigid and nonfunctional ankle.
Conclusion
The combined regenerative approach using morselized bone tissue and DHDM, both infiltrated with homologous PRP in a “one-step” surgical procedure can be considered the first step of a new regenerative approach to the problems based on the use of regenerative medicine.
