ADVERTISEMENT
A Guide To Revising First MPJ Arthrodesis With Combined Allograft And Autograft
These authors explore a surgical technique that combines autogenous bone graft and allograft for revisional first metatarsophalangeal joint arthrodesis after nonunion.
In the management of nonunions following first metatarsophalangeal joint fusions, surgeons often utilize bone graft to augment the construct and increase the chances for osseous union. Nonunions are a major complication in foot and ankle surgery, and occur in approximately 12 percent of cases.1 One can diagnose a nonunion, the complete cessation of bone healing, both clinically and radiographically. While the time required to make a true diagnosis varies within the literature, one typically diagnoses nonunions six to nine months after surgery.2
There are various factors that may increase a patient’s risk for nonunion. Some of the factors that have been found to potentiate risk of the nonunion and other non-infectious complications include: positive smoking history, previous attempted fusion, presence of avascular bone, diabetes mellitus, previous solid organ transplantion, and poor preoperative serum glucose control (>200mg/dL).3 Also, based on the current literature, resesarchers have found that neuropathy and prior revision surgery attempts are statistically significant risk factors for nonunion.3
In revisional procedures for nonunions, the use of bone graft is common. Autogenous bone graft is ideal in many scenarios because it supports osteogenesis, osteoinduction and osteoconduction.4 The disadvantages of autograft include limitations in quantity, donor site morbidity and infections as well as other complications from the donor site. While foot and ankle surgeons commonly employ allograft, a major disadvantage is that all viable cellular components are destroyed during the processing of the graft, which eliminates any osteogenic properties. However, in revisional cases, especially in nonunion cases that require bone resection, allograft can be of great benefit for restoring length in the surgical site.
In this case study, we describe an innovative grafting technique, which incorporates both allograft and autograft, for foot and ankle revisional nonunion procedures in order to explore the utility and efficacy of the procedure.
How To Perform Calcaneal Autograft Harvesting
After ensuring supine positioning of the patient with the toes pointing superiorly, one can direct attention to the lateral aspect of the patient’s calcaneus. Employing intraoperative fluoroscopy as a guide for incision planning at the body of the calcaneus, one can avoid the the sural nerve and subtalar joints.
Utilizing a #15 blade, create a 3 cm linear horizontal incision through the skin only. Carry blunt dissection down to the level of the lateral cortex of the calcaneus, avoiding any neurovascular structures. Create an incision over the overlying periosteum and capsule. Reflect this dorsally and medially to allow for great visualization of the lateral wall of the calcaneus (see Figure 1).
Utilizing a small osteotome and a mallet, create a small window from lateral to medial to the level of the medullary bone in order to allow for access for harvesting. After achieving this, use a curette to scoop medullary bone and cancellous bone from the calcaneus. Place the harvested bone graft in a sterile cup for later use. Once one has harvested an adequate amount, irrigate the wound site with copious amounts of sterile saline and use demineralized bone matrix to backfill the area created from harvesting. Once you have filled this area, reapproximate the deep tissue with 3.0 Vicryl. Reapproximate the subcutaneous tissue with 4.0 Vicryl and reapproximate the skin with 4.0 prolene in a simple interrupted type pattern.
Step-By-Step Pearls For The First MPJ Procedure
Next, attention is directed to the dorsal medial aspect of the foot over the first metatarsophalangeal joint where the previous arthrodesis was performed. Utilizing a #15 blade, make a 6 cm dorsal linear incision over the first metatarsophalangeal joint and just medial to the extensor hallucis longus tendon. At this time, carry blunt dissection down to the level of the periosteum and the capsule. Create a linear dorsal capsular incision and then reflect the capsule both medially and laterally. If necessary, the surgeon can remove any hardware from previous surgery at this time.
One can visualize the first metatarsophalangeal joint at this time. Completely debride first MPJ space until it is free of soft tissue, and implant material. Utilizing a sagittal saw, resect the nonunion site until you note good, viable bone. Fenestrate the bone at this time to stimulate bleeding and help facilitate fusion. At this time, the joint preparation for arthrodesis is complete and one is ready to move on to graft application.
After 15 minutes of soaking the iliac crest allograft in sterile saline, prepare the graft by cutting it to the correct size. Fenestrate the allograft with a 0.045 K-wire (see Figure 2). Distract the joint and insert the prepared allograft. Intraoperative flouroscopy is utilized to insure adequate length is present to maintain a normal metatarsal parabola. Finally, pack both ends of the graft with calcaneal autograft harvested from the previous procedure (see Figure 3).
Use intraoperative fluoroscopy again to verify the length and overall position of the first ray in all three planes for arthrodesis. Utilizing AO fixation technique, proceed to fuse the first metatarsophalangeal joint, employing an internal fixation method of your preference. One should ensure good apposition and position of the first ray in all planes, and verify the adequate compression of allograft as well as its associated calcaneal autograft (see Figure 4).
Gently flush the wound site with sterile saline and proceed to wound closure. Reapproximate the capsule tissue with 3.0 vicryl, reapproximate the subcutaneous tissue with 4.0 vicryl and reapproximate the skin with 4.0 Prolene in a horizontal mattress type stitch pattern.
Final Words
Treatment of first metatarsophalangeal joint nonunions can be a difficult task. Our technique of combining autograft with allograft proved to be useful in maintaining the length of the first ray while also improving fusion rates in our patients. Further research is necessary however to show advantages of this technique over allograft- or autograft-only techniques.
Dr. Brancheau is board-certified by the American Board of Foot and Ankle Surgery, and the American Board of Podiatric Medicine. He is a Past President of the Texas Podiatric Medical Association. Dr. Brancheau is in private practice at multiple office locations in Texas.
Dr. Lee is a third-year resident at Hunt Regional Medical Center in Greenville, Texas.
Dr. Duffin is a third-year resident at Hunt Regional Medical Center in Greenville, Texas.
References
1. Thevendran G, Shah K, Pinney SJ, Younger AS. Perceived risk factors for nonunion following foot and ankle arthrodesis. J Orthop Surg. Available at: https://doi.org/10.1177/2309499017692703 . Published February 20, 2017. Accessed May 28, 2019.
2. Mendicino S, Rockett A, Wilber M. The use of bone grafts in the management of nonunions. J Foot Ankle Surg. 1996; 35(5):452-457.
3. Yeoh J, Taylor B. Osseous healing in foot and ankle surgery with autograft, allograft, and other orthobiologics. Orthop Clin North Am. 2017;48(3):359–369.
4. Mahan K. Bone grafting. In: McGlamry ED, Banks AS, Downey MS (eds): Comprehensive Textbook of Foot Surgery, Ch 38, Williams and Wilkins, Baltimore, 1992; pp. 1232-1254.
