A National Leader in the Clinical Application and Research of Osseointegration for Prosthetic Limbs

December 16, 2020

Transcutaneous osseointegration (OI) for attaching prosthetic devices to an individual who has experienced an amputation due to disease (e.g., cancer), or traumatic injury (e.g., automobile accident, battlefield injury), or failed arthroplasty (e.g., knee), has been in practice for several decades in Europe and Australia. The first procedure was performed in Sweden in 1990 by Branemark et al. Since that time, several device systems and operative techniques have been developed and deployed for lower and upper extremities. OI has only more recently found its way to the United States in the last 10 years, and it was only in 2015 that the U.S. Food and Drug Administration (FDA) approved the OPRA™ system for use.

The osseointegration program within the UPMC Orthopaedic Care department is led by Richard L. McGough III, MD, professor of orthopaedic surgery, chief of the Division of Musculoskeletal Oncology, and co-director of the Sarcoma Specialty Center at UPMC Hillman Cancer Center. Dr. McGough's chief clinical research interests involve OI, and he also studies the use of BrachyVAC surgery, a technique he pioneered at UPMC for treating superficial spreading sarcomas with optimal oncologic and reconstructive outcomes. The osseointegration program at UPMC brings together orthopaedic surgery, physical medicine and rehabilitation, and behavioral health disciplines for multidisciplinary assessment, care, and follow-up for its patients.

Dr. McGough’s clinical work and research with osseointegration dates to approximately 2010, when he traveled to Germany to first study the systems and techniques of OI. In 2012, Dr. McGough established the osseointegration program in the Department of Orthopaedic Surgery at UPMC. He was one of the first surgeons to bring OI to the United States, and performed some of the first lower extremity OI procedures in the U.S. Additionally, Dr. McGough the first orthopaedic surgeon in the U.S. to use OI for an upper extremity amputation. Because of his work and expertise, Dr. McGough sits on an extramural U.S. Department of Defense (DOD) steering committee for its osseointegration program and use in U.S. armed forces personnel.

“Prior to 2015 and FDA approval, anyone in the United States desiring osseointegration for their prosthetic device had to travel abroad, to either Europe and Australia. Now, there is increasing momentum in the U.S. for OI, but rightly so, the FDA keeps strict control on its use to ensure providers are adequately trained and capable of achieving optimal outcomes. No one–surgeons, health care systems, and patients–should pursue this lightly. Patients must be ideally suited for OI, and providers must be equally adept at its performance. However, when those criteria are met, OI can be of tremendous benefit,” says Dr. McGough.

Benefits of Osseointegration for Amputees

It probably goes without saying that while prosthetic technologies to replace amputated limbs have advanced markedly during the last several decades, these devices remain to be, by most comparisons to the native anatomy they replace, crude substitutes. Biomedical engineering and surgical advancements may one day replicate the form, function, and sensory perception of an arm or leg, but that day is far in the future. Until then, we have at our disposal the current crop of prosthetic limbs.

Osseointegration entails the implantation of a metal connector directly into the patient’s bone, for example the femur. The device is implanted in a manner such that new bone growth forms around the device, firmly anchoring it in place. The end of implant that attaches to the patient’s prosthetic limb protrudes through the skin. The remaining part of the individual’s limb is contoured in a manner that facilitates optimal fit between it and the prosthetic.

Osseointegration can provide patients with a number of benefits. First is a level of proprioception for a leg or arm that devices which are attached through a more traditional socket fixture simply cannot match. This has numerable benefits for the user. Lower extremity prostheses connected via OI provide much more sensory data about the limb's position and impact with surfaces or objects during movement. It allows users to receive more external feedback via sensations conducted from the device to the existing limb, which allows for more normal walking ability.

"Complications related to OI devices mostly manifest as skin issues and infections, assuming that patients have been screened and well-selected for OI to eliminate those individuals who may not be able to cope long-term or are unsuitable for other reasons. There is a risk of nonunion between bone and the metal implants, but this tends to be low. While the human body was not designed to have foreign bodies embedded and protruding from it, we can successfully mitigate the potential complications, but it requires diligence and a committed patient," says Dr. McGough.

For individuals who are high-performing and have the desire and abilities to carry on with the activities they were engaged in before losing the limb, and who can successfully navigate the psychological and physical aspects related to OI, along with the long-term maintenance requirements of the device, OI may be an ideal option.

Who Makes For an Ideal OI Candidate?

Not all amputees will be ideal candidates for OI. There are a number of criteria and factors that Dr. McGough and colleagues must take into account while assessing and counseling prospective patients. 

There are two broad categories of amputee patients that comprise the majority of candidates. The first are those individuals who are exceptionally high functioning or who could be high functioning. These individuals could perform at higher levels of function with OI than with a prosthetic with a socket attachment. 

"In this group, think athletes and military personnel with rigorous duties," says Dr. McGough.

The second category of patients is those individuals who will never function well with a socket-type prosthetic. These individuals may have a limb length too short for a socket device, or those individuals with double amputations that would make socket devices exceptionally difficult to use. Weight also can be a factor. Heavier individuals can have difficulty with socket-type devices.  

Individuals with amputations related to underlying diabetes or vascular conditions are not candidates for OI at UPMC, as are those with very high leg amputations which do not allow for ample bone structure to attach the implant.

However, individuals that have experienced some form of traumatic limb loss, cancer patients whose treatment necessitated the amputation of a limb, and even individuals who have failed total knee replacements generally make for good candidates assuming other criteria are met.

Precluding Factors: Patient Screening Is Critical to Long-Term Outcomes

OI can present a number of challenges for patients. Some of these challenges may be insurmountable and lead to poor outcomes and even explant of the device. As Dr. McGough explains, the screening and counseling process is crucial to determining if a patient is an ideal candidate for OI.

OI devices require a good deal of maintenance, and this maintenance will be needed for the duration of the person's life. Patients must be willing and able to manage this aspect to achieve optimal outcomes. Furthermore, not everyone is mentally stable enough to handle osseointegration.

“The behavioral health aspects of having a prosthetic, and one that attaches through an OI with a large, protruding piece of metal through the skin can be daunting. Screening for types and levels of body image dysmorphism is needed to identify potential poor candidates for OI. From a psychological standpoint, we have learned that this can be difficult to overcome and can lead to the individual desiring removal of the implant. This is why we have integrated a behavioral health component to our program," says Dr. McGough. 

OI Research at UPMC

In 2017, Dr. McGough, and former Department of Orthopaedic Surgery colleague, Mark Goodman, MD, published findings from a multicenter pilot study with colleagues from the University of Utah and Walter Reed National Military Medical Center on their initial series of patients to undergo OI using the Compress® transcutaneous OI implant.

Thirteen patients were included in the study, all of which were lower extremity cases of OI for either oncologic, traumatic, or failed arthroplasty indications. Postoperative complications were observed in only three cases for infection, periprosthetic fracture, and a taper mismatch, which was corrected. 

"The findings from this initial case series shows significant results and provide the basis for further studies that we expect will ultimately help lead to FDA approval for this device in the U.S. in the future. While OI has a proven track record outside the United States, and our own institution's experience is significant and expanding, I am cautiously optimistic about OI's future in the United States. It is clear that OI is not suitable for every patient and that much more study needs to be accomplished in this clinical space, but there are distinct benefits for patients with these devices.”

References and Further Reading

McGough R, Goodman M, Randall R, Forsberg J, Potter B, Lindsey B: The Compress® Transcutaneous Implant for Rehabilitation Following Limb Amputation. Der Unfallchirurg. 2017; 120: 300-305.

van Eck CF, McGough R. Clinical Outcome of Osseointegrated Prostheses for Lower Extremity Amputations: A Systemic Review of the Literature. Curr Orthopaed Prac. 2015; 26: 349-357.

“OPRA™ is a trademark of Integrum, Inc.”
“Compress® is a trademark of Biomet Manufacturing, LLC.”