Bioadjuvants for complex ankle and hindfoot reconstruction

Biologic Augmentation of Tibiotalocalcaneal Arthrodesis With Allogeneic Bone Block Is Associated With High Rates of Fusion

BACKGROUND

The orthopaedic conditions and systemic comorbidities that occur in patients who require bone block tibiotalocalcaneal (TTC) arthrodesis have made this procedure associated with a higher-than-normal risk of nonunion, graft collapse, hardware failure, and amputation. Here, we present a novel approach to bone block TTC arthrodesis using adjunctive osteoinductive agents and a prolonged course of protected weightbearing to assess if we could improve on historical outcomes. We also evaluated the efficacy of a vascularized medial femoral condyle (MFC) free flap to augment TTC arthrodesis.

METHODS

Fourteen adult patients underwent bone block TTC arthrodesis biologically augmented with fresh-frozen femoral head allograft, bone marrow aspirate concentrate, and demineralized bone matrix cortical fibers. Three patients with soft tissue defects underwent vascularized reconstruction with an MFC free flap. Radiographic union, the Foot Function Index (FFI), and PROMIS pain interference (PI), and physical function (PF) scores were assessed at follow-up.

RESULTS

TTC fusion was documented on plain radiograph in 13 of 14 patients (92.9%) and CT in 10 of 11 patients (90.9%). Mean time to fusion was 183.2 ± 83.2 days. One patient (7.1%) experienced nonunion and persistent infection requiring amputation. Patients who underwent vascularized bone grafting had significantly shorter time to fusion (112.3 ± 31.7 days vs 204.4 ± 82.7 days, P = .05). Patient-reported outcomes revealed mild to moderate pain and dysfunction after 1 year (mean FFI = 41.0% ± 23.1%, PROMIS PI = 58.3 ± 1.8, PROMIS PF = 39.0 ± 2.2).

CONCLUSION

In this relatively small series, the biologic augmentation of bone block TTC arthrodesis with osteoinductive agents and protective weightbearing resulted in excellent rates of fusion, modest pain, and preserved function of the lower extremity in almost all those treated. Osseous healing appears to be enhanced and accelerated with application of an MFC flap. We believe that this approach offers a viable salvage option for these challenging clinical problems.

LEVEL OF EVIDENCE

Level IV, case series.

What Is the Treatment "Algorithm" for Infection After Ankle or Hindfoot Arthrodesis?

RECOMMENDATION

There is no universal algorithm for addressing the infected ankle or subtalar arthrodesis. A potential algorithm created by consensus is.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

The Biology of Bone and Ligament Healing

This review describes the normal healing process for bone, ligaments, and tendons, including primary and secondary healing as well as bone-to-bone fusion. It depicts the important mediators and cell types involved in the inflammatory, reparative, and remodeling stages of each healing process. It also describes the main challenges for clinicians when trying to repair bone, ligaments, and tendons with a specific emphasis on Charcot neuropathy, fifth metatarsal fractures, arthrodesis, and tendon sheath and adhesions. Current treatment options and research areas are also reviewed.

Complex ankle arthrodesis: Review of the literature

Complex ankle arthrodesis is defined as an ankle fusion that is at high risk of delayed and nonunion secondary to patient comorbidities and/or local ankle/hindfoot factors. Risk factors that contribute to defining this group of patients can be divided into systemic factors and local factors pertaining to co-existing ankle or hindfoot pathology. Orthopaedic surgeons should be aware of these risk factors and their association with patients' outcomes after complex ankle fusions. Both external and internal fixations have demonstrated positive outcomes with regards to achieving stable fixation and minimizing infection. Recent innovations in the application of biophysical agents and devices have shown promising results as adjuncts for healing. Both osteoconductive and osteoinductive agents have been effectively utilized as biological adjuncts for bone healing with low complication rates. Devices such as pulsed electromagnetic field bone stimulators, internal direct current stimulators and low-intensity pulsed ultrasound bone stimulators have been associated with faster bone healing and improved outcomes scores when compared with controls. The aim of this review article is to present a comprehensive approach to the management of complex ankle fusions, including the use of biophysical adjuncts for healing and a proposed algorithm for their treatment.

Complex ankle arthrodesis: Review of the literature

Complex ankle arthrodesis is defined as an ankle fusion that is at high risk of delayed and nonunion secondary to patient comorbidities and/or local ankle/hindfoot factors. Risk factors that contribute to defining this group of patients can be divided into systemic factors and local factors pertaining to co-existing ankle or hindfoot pathology. Orthopaedic surgeons should be aware of these risk factors and their association with patients’ outcomes after complex ankle fusions. Both external and internal fixations have demonstrated positive outcomes with regards to achieving stable fixation and minimizing infection. Recent innovations in the application of biophysical agents and devices have shown promising results as adjuncts for healing. Both osteoconductive and osteoinductive agents have been effectively utilized as biological adjuncts for bone healing with low complication rates. Devices such as pulsed electromagnetic field bone stimulators, internal direct current stimulators and low-intensity pulsed ultrasound bone stimulators have been associated with faster bone healing and improved outcomes scores when compared with controls. The aim of this review article is to present a comprehensive approach to the management of complex ankle fusions, including the use of biophysical adjuncts for healing and a proposed algorithm for their treatment.

Effect of Osteogenic Progenitor Cell Concentration on the Incidence of Foot and Ankle Fusion

The use of biologics, namely demineralized bone matrix, bone marrow aspirate (BMA), and other growth factors, has gained popularity in foot and ankle surgery for use in compromised hosts or high-risk situations. Our research has shown the concentration of these pluripotent cells was greatest in the iliac crest. A medical record and radiographic review was performed to compare the effect of BMA harvest site osteogenic progenitor cells on the incidence of fusion. Radiographs were reviewed for radiographic evidence of trabecular bridging in 2 or more views. If fusion occurred, the number of osteogenic progenitor cells found in the combined BMA at surgery was recorded. A total of 33 patients were included in the present study. Of the 33 patients, 32 (97.0%) had radiographic fusion at a mean of 13 ± 6 (range 8 to 30) weeks, and 1 (3.0%) experienced nonunion and required revision. The patient procedures were as follows: 18 (54.5%) hindfoot arthrodeses, 8 (24.2%) forefoot arthrodeses, 4 (12.1%) fractures, and 3 (9.1%) isolated ankle fusions. The mean colony-forming units for the patients with fusion was 20.3 ± 23.5 (range 0.0 to 107.0). In the patient with nonunion, it was 0.20 colony-forming unit. Our comparison of the incidence of fusion with the use of osteogenic progenitor cells from 3 anatomic sites showed a low incidence of complications and a high incidence of fusion. No association was found between the BMA concentration and the incidence of fusion, suggesting a minimum concentration and biologic potential of pluripotent cells is necessary to achieve the clinical effect of fusion.

Complications of digital and lesser metatarsal surgery

Complications associated with digital and lesser metatarsal surgical procedures have been well documented in the literature. These complications may stem from systemic medical, structural, biologic, biomechanical, or iatrogenic causes. The surgeon must be cognizant of all potential complications, including ways to prevent them from occurring and how to manage them when they do occur. This article discusses preventative measures through the preoperative evaluation of the patient, and examines the subsets of complications that may occur after lesser ray surgery that pose a particular management challenge, as well as special complications specific to particular operative techniques.

Utilization of advanced modalities in the management of diabetic Charcot neuroarthropathy

Technological advances have allowed reconstructive foot and ankle surgeons greater opportunity to provide significant limb salvage options to those patients who present with significant lower extremity deformity due to diabetic Charcot neuroarthropathy. Paradigms that promote the utilization of these advanced modalities have demonstrated significant improved limb salvage outcomes in this challenging patient population and have consequently improved the quality of life for patients. The purpose of this review is to discuss current concepts in Charcot reconstruction.

Use of platelet-rich concentrate and bone marrow aspirate in high-risk patients with Charcot arthropathy of the foot

BACKGROUND

Diabetic patients with Charcot arthropathy of the foot are at high risk for nonunion when undergoing arthrodesis. There is increasing evidence that cytokines identified in platelet rich concentrate and bone marrow aspirate may show equivalence to autologous bone graft in supporting arthrodesis.

MATERIALS AND METHODS

Prospectively, 44 high-risk diabetic patients with Charcot foot arthropathy underwent surgical correction of 46 feet through a limited surgical approach. The average age of the patients was 54.9 +/- 10.4 years. Their mean BMI was 38.0 +/- 9.7. Twenty-four were male and 20 were female. Twenty-eight had open wounds with chronic draining osteomyelitis. Surgical correction was maintained postoperatively with static circular ring fixation. At the time of wound closure, all of the patients had injection of autologous platelet rich concentrate and bone marrow aspirate.

RESULTS

Forty-two of the 46 feet had radiographic evidence of bony union at 26.2 +/- 12.2 months following surgery. One patient died of unrelated causes. Two underwent amputation for persistent infection. Six had recurrent ulcers which resolved with local treatment. One patient required a fifth ray resection for gangrene following surgery. There were three tibial stress fractures, with two requiring intramedullary nailing to achieve union.

CONCLUSIONS

Platelet-rich concentrate, when combined with a small amount of autologous bone marrow aspirate, may well be as effective as autologous bone grafting when performing arthrodesis of high risk diabetic patients with Charcot foot arthropathy.

Minimally invasive soft-tissue and osseous stabilization (MISOS) technique for midfoot and hindfoot deformities

The surgical repair of unstable midfoot and hindfoot deformities in the high-risk patient remains a challenge with little guidance available in the literature. The author presents a proposed surgical intervention for midfoot and hindfoot deformities utilizing a minimally invasive soft-tissue and osseous stabilization (MISOS) approach. The article presents a detailed, step-by-step description of the procedure used for these difficult limb salvage cases.

Principles of arthrodesis and advances in fixation for the adult acquired flatfoot

Arthrodesis continues to be the procedure of choice in treatment of the end-stage adult acquired flatfoot. Its goals are to provide pain relief, correct the deformity, and improve function and stability. A better understanding of anatomy and operative technique has led to significant refinements and advances in fixation. These devices have proved useful in arthrodesing and tenodesing procedures. The principles in achieving a sound arthrodesis and the various forms of fixation are discussed in detail.