What is osseointegration?
Osseointegration is derived from the Greek word “osteon” meaning bone, and the Latin “integrare”, which means to make whole. The term is defined as the contact between living bone and the surface of a synthetic, often titanium based, load bearing implant.
Osseointegration’s original application was in bone and joint replacement surgeries and not only has it dramatically enhanced these surgeries and their outcomes, but now it is also used to vastly improve the quality of life for amputees.
Sir John Charnley pioneered hip replacement surgery in 1962. His design and approach involved attaching the replacement prosthesis to the bone, which he based on a dental practice that utilized bone cement. His revolutionary technique is still used today.
The concept of osseointegration in dentistry first started in 1965 with Professor Per-lngvar Branemark who threaded trans-oral titanium implants into the mandible and maxilla (the bones of the upper and lower jaw) to act as anchorage for dental prostheses.
In 1990, based on a successful technique developed by his father, Rickard Branemark performed the first transcutaneous femoral intramedullary osseointegration surgery on an above knee amputee with a 12-cm screw-fixation titanium threaded device. A non weight-bearing period of six to twelve months was applied to allow proper osseointegration.
Osseointegration for amputees has been in clinical use since 1995 utilizing a skeletally integrated titanium “implant, which is connected through an opening (stoma) in the residual limb to an external prosthetic limb. The socket component of the traditional prosthesis is no longer required. Attachment between the external portion of the implant and the prosthetic knee is achieved via a torque-controlled knee connector. This allows direct contact to the ground, which provides greater stability, more control, and minimizes energy consumption.
Say goodbye to your socket!
OGAAP-OPL: The Osseointegration Group of Australia (OGA) is an organization founded by Sydney orthopedic surgeon Associate Professor Munjed AI Muderis. The group consists of a team of highly qualified medical professionals offering support before, during, and after osseointegration surgery. Using a multi-disciplinary team approach, the group provides those with amputations the possibility of improved mobility utilizing the newest innovation in the field of osseointegration.
Imagine a prosthesis that isn’t bulky, cumbersome, and didn’t cause rubbing due to poor fit. With the Osseointegration Group of Australia Accelerated Protocol — Osseointegration Prosthetic Limb (OGAAP-OPL), mobility is restored as close as possible to that of an able-bodied person and life as an amputee is dramatically changed for the better.
What is OGAAP-OPL?
The OGAAP-OPL is a revolutionary type of prosthesis for both upper and lower extremity amputees that makes a conventional socket unnecessary. Problems associated with conventional sockets such as rubbing, chaffing, and pressure sores have remained largely unsolved despite extensive and continuing research in socket design and manufacturing. A/Prof Al Muderis (who is the OGAAP-OPL designer), along with the manufacturers, have many years of experience in the field of internal prosthesis design and production. They used evidence of proven clinical history to deliver a safe result that enables mobility and movement without a suction prosthesis.
What makes the OGAAP-OPL so innovative is the fact that it is modeled on the anatomy of the human body and takes the load back directly to the bone and the associated muscles. The OGAAP-OPL is implanted directly into the bone and encourages bone growth. Once integrated, it allows for a simple, quick, and safe connection between the residual limb and the lower prosthesis. No longer is the prosthesis merely attached to the person via a socket, but it becomes part of the person’s bone structure, resulting in greater comfort and walking control.
BEFORE: Unnatural position of the femur in a socket prosthesis.
AFTER: Femur position is more anatomically correct.
Below knee osseointegration.
Advantages
- No Socket: The major advantage of the OGAAP-OPL is the absence of a socket. This ensures the prosthesis always fits comfortably, always attaches correctly, and is always held firmly in place regardless of activity level, fluid fluctuations, perspiration levels, or weight loss/gain. It also allows for a natural streamlined look in clothing.
- Easy Attachment: With osseointegration, taking the prosthesis on and off involves little more than tightening/loosening a single adapter screw.
- Cost Saving: With the OGAAP-OPL, the need for frequent sockets and associated supplies is eliminated, which represents significant cost benefits.
- Improved Gait: Following osseointegration, increased muscle use and control frequently results in a more natural walking gait. Improvements in the range of movement and natural pivoting in the hip and knees also contribute to an improved gait.
- Increased Mobility: Osseointegration allows for full freedom of movement from walking to cycling and recreational activities. Movement is no longer restricted by the protruding edges of a socket, allowing for greater ease and comfort when sitting, standing, walking, or engaging in vigorous sports activities such as speed cycling or rowing.
- Muscle & Bone Strength: Walking with the OGAAP-OPL allows for natural loading of the hip joint and the femur, which encourages bone growth. Muscle strength is developed freely, and walking requires significantly less physical exertion.
WHY OSSEOINTEGRATION?
Improved Quality of Life.
People with above or below knee amputations seek to return to a mobile lifestyle. Conventional rehabilitation uses a socket prosthesis, which is fixed to the soft tissue of the remaining residual limb using suction or vacuum. The artificial knee joint and/or lower leg prosthesis is then attached to the socket. This enables the patient to walk without aid, but there are several challenges in the use of a suction prosthesis. One important factor is the length of the remaining limb, as it determines the lever arm and the force, which must be applied for conducting, guiding, and controlling the prosthesis. If the socket does not fit properly, it can create skin irritations of the soft tissue which may lead to sores, ulcers, and chronic inflammation with abscesses and pain.
Moreover, the remaining stump length correlates with the energy expenditure during walking. On average, an amputee uses 70% more energy than an able-bodied person. These difficulties can result in poor gait with negative effects on the remaining musculoskeletal system. This often leads amputees to utilize walking aids or even a wheelchair.
Hence a prosthesis that avoids the skin and soft tissue interface eliminates:
- Skin irritation due to friction, chaffing, and squeezing.
- Increased sweating and heat rashes.
- Inflammation, bruises and hematoma, pressure marks, and even deep skin injuries.
- Dissatisfying fir of the prosthesis due to variation of weight and stump volume.
- Pain and discomfort even while sitting.
- Hygiene problems.
For many amputees, it is difficult to find a way back into an active lifestyle or to the work force. Often, they cannot perform activities or sports, and have to rely on the help of others during everyday life.
Osseoperception.
Following osseointegration surgery, the patient regains their sense of proprioception, which is the unconscious perception of the position of the body, movement, and spatial orientation in relation to the external environment. This means that patients regain the ability to feel the ground beneath them as they walk and differentiate between different surfaces such as grass, carpet, tile, uneven ground, and gravel. This allows for safer and more confident movement even in unfamiliar areas or dim light.
IMPLANT TECHNOLOGY
How does the OGAAP-OPL work?
The OGAAP-OPL is made up of several different components that can be divided into an internal (endo) module and an external (exo) module. The endo module, a titanium stem, is directly implanted into the bone. There are a range of implants to meet the needs of varying patients.
The implant surface is highly porous titanium, which allows initial stability and long-term bone integration (in-growth). This technology has been successful in clinical use around the world for more than 30 years in joint replacement surgery. The biocompatibility of the titanium implant allows the bone to grow inside the surface of the prosthesis, which makes the bone-implant structure one solid unit. This is known as osseointegration.
A dual cone extension connects the internal implant to the external prosthesis. This extension has a highly polished smooth surface to minimize soft tissue friction. It is also coated with titanium niobium, which has antibacterial properties. This passes through a small opening in the skin known as the stoma.
Externally, the dual cone extension is fixed to a torque-controlled safety device comprised of a taper sleeve connector and an anti-rotational locking bushing that are held together by a locking fixture. This further connects to an adapter that then connects to the lower prosthetic limb.
There are different adapters available, with different features, yet all are compatible with the various prosthetic componentry in today’s market.
Osseointegration Prosthetic Limb (OPL) Implant for Lower Leg Amputee
Easy Attachment
Donning and doffing the prosthesis is very easy and takes less than ten seconds. Due to the solid fixture to the bone, it accurately connects to the exact spot each and every time the prosthesis is attached. The OGAAP-OPL can be used with all types of prosthetic componentry.
Gone are the days of huffing and puffing, fiddling around with time consuming and cumbersome suction, sockets, and liners.
TEAM APPROACH
The Osseointegration Group of Australia (OGA). Established in 2010.
The 1st osseointegration surgery was undertaken in March 2011. The OGA provides a team approach to assist amputees with the possibility of greater and more effortless mobility by utilizing the latest innovation in the field of prosthetics. The team consists of experts in a variety of fields, each with vast experience working with amputees. They understand every situation and every patient is unique. By utilizing a combined team approach, they work together to assess and determine the best possible treatment for each patient.
The team cares for their patients emotionally and physically from the first meeting. Open communication is a vital part of the osseointegration procedure performed by the OGA team. They offer support and expert guidance through all stages of the osseointegration procedure; from choosing to undergo surgery, to the surgery itself, through after care in pain management, physiotherapy, and prosthetic adjustments that are best suited to the patient.
The OGA team is made up of the following medical professionals:
- Orthopedic Surgeon (A/Prof Munjed Al Muderis
- Practice Nurse / Surgical Assistant
- Prosthetist
- Acute Care Nurse
- Physiotherapists
- Rehabilitation Physician
- Anesthetist
- Patient Advocates
- Biomedical Engineer
- Psychologist
- Patient Coordinator
GETTING STARTED
Who is a candidate for osseointegration?
All prospective patients are directed to complete a secure online enquiry form available on the OGA website at: www.osseointegrationaustralia.com.au
Candidates initially excluded may be reconsidered if circumstances changes…
Exclusion Criteria:
- Peripheral Vascular Disease
- Receiving Chemotherapy
- Receiving Irradiation
- Mentally Unstable
- Unrealistic Expectations
- Smoking
- Growing Skeleton
- Non-compliance
A/Prof Al Muderis and members of his team will review all available information to evaluate the initial suitability of the candidate and a plan for the individual will be agreed upon.
Once all assessments have been carried out, the team will discuss the candidate’s case and make the decision whether to proceed with surgery.
The candidate will meet with the team’s prosthetist, who will conduct a series of gait measurements, tests, and assessments. The team’s physiotherapist will run through a series of pre-surgery strengthening exercises to do prior to surgery.
A/Prof Al Muderis and his surgical team will then make the necessary preparations for surgery. The anesthetist and pain management specialist will consult with the patient about what anesthetic will be best and run through the post-surgery pain management protocol.
In the case of surgery being done in South Africa?
The OGA will be coming to Cape Town, South Africa, at the end of every year to perform the osseointegration surgeries. All pre-assessments will be conducted through the prosthetist Eugene Rossouw Orthotist and Prosthetist at the practice in Milnerton, Cape Town. https://www.prostheticrehabclinic.co.za
All osseointegration information available here: https://www.prostheticrehabclinic.co.za/services-portfolio/osseointegration/
SURGERY
Hospital Admission.
The patient is admitted to the hospital on the night before or on the same day as the surgery. It is extremely important for the patient to bring all x-rays, CT scans, and MRIs applicable to the operation during admission. Patients are advised to bring a family member or friend with them for support.
What happens during the operation?
The surgical procedure involves permanent insertion of an osseointegration implant into the residual bone of the operated limb.
The OGA team originally developed the OGAAP-1 osseointegration protocol which revolves around a two-stage surgery with a 4–6-week interval between the two stages. Until very recently, the vast majority of osseointegration procedures worldwide have been performed in two stages. From the time of initial surgery, these procedures typically required up to 12-18 months for the completion of reconstruction and rehabilitation, and at least 4-5 months even under the OGAAP-1 protocol. Since April 2014, however, the OGA team has developed and routinely performs a single surgery under the OGAAP-2 protocol. This protocol reduces the overall time required for reconstruction and rehabilitation to approximately 3-6 weeks, which is substantially shorter than the two-stage surgery. A single surgery also minimizes the risks associated with multiple surgeries, reduces time away from work and family, and reduces costs. However, no two osseointegration patients are identical, and while single-stage surgery may be suitable for some people, two-stage surgery may be the best solution for others.
Patients are selected for either procedure by the OGA team based on pre-operative assessments, and the surgical process varies slightly from patient to patient depending on their existing condition and needs.
During the surgical procedure.
- The soft tissue is managed, and redundant skin and soft tissue fat are removed to minimize the bone to skin distance. This leads to a reduced chance of complications. The muscle groups are rearranged to serve a functional purpose in operating the leg and the soft tissue facial layer is reorganized around the stem.
- The bone canal is prepared using a specialized instrument. The internal component of the implant is press-fitted into the bone canal securing early stability and future bone in-growth.
- If there is a neuroma causing nerve pain, the nerves involved are addressed surgically by excision of the painful neuroma and deep positioning of the residual nerve into the fat tissue to minimize future nerve issues.
Post Surgery – How is pain managed?
The surgery is usually performed under a combined spinal/epidural and general anesthesia to achieve optimal pain management post-surgery. However, this may change depending on the patient’s medical condition or suitability for certain anesthetic modalities. Ongoing intravenous infusion of pain medications continues for the first three days post-surgery. Once these are removed, the patient is assessed for commencement of rehabilitation procedures and discharge from the hospital. Upon release from the hospital, it is important to continue with oral medications as instructed by the anesthetist/pain specialist. The regime is designed to minimize not only surgical pain, but also to minimize any phantom/referred/neurogenic limb pain.
How long before walking can commence?
Approximately 3-5 days post-surgery, the patient begins a static weight-loading regime. Weight loading starts at a relatively small amount of weight for a short period of time and increases daily until approximately 50% of the patient’s body weight is reached. After reaching the target loading weight (10-14 days post-surgery), the patient is fitted with a temporary light-weight prosthesis and walking commences with the use of aids. Once walking unassisted with crutches and pain is well controlled, the patient can start walking using a definitive prosthesis, first on two crutches for 6 weeks, then on a single crutch for another 6 weeks, and unaided thereafter.
STOMA CARE
How is the stoma cared for?
Following surgery, there will be a metal abutment protruding from the skin with a dry gauze dressing that should be changed daily or as needed if excessive discharge is present.
The stoma area should be kept clean and dry for two weeks post-surgery and protected with waterproof materials when showering. After two weeks, the area should be washed twice daily with warm tap water and soap, and pat dry. Staples are used to close the skin and are removed 14-16 days post-surgery.
Continued discharge from the stoma is common and varies from patient to patient, while some people have none. Discharge accumulated on the abutment should be removed with a soft shaving brush or toothbrush on an ongoing basis. Brushes should be replaced at least once a month.
An example of a stoma at 14 months post-surgery.
FACTORS TO CONSIDER
There are hundreds of satisfied osseointegration users with this type of prosthesis who can testify that this technology offers significant and unparalleled advantages compared to a traditional socket prosthesis. For many who were unable to use a socket prosthesis, osseointegration has allowed them to walk again after years of being bound to a wheelchair or crutches.
Sensible handling of the prosthesis and simple common sense can prevent any chance of future problems. To ensure the implant is safely integrated into the bone, patients are required to only partial weight-bear for the first 12 weeks. This means walking with at least one crutch or walking stick for this period.
While it is a very exciting time and the urge to push oneself is often strong, it is recommended that the patient slowly build up to walking to avoid any injuries caused by pushing too hard, too soon.
As a general rule, excessive rotation such as pivoting and sharp twisting should be avoided. However, if high levels of strain should occur, the safety shear pins in the external implant system will break to protect against a bone fracture occurring. The system yields and the bone remains undamaged. Safety is a priority and the system has been designed to protect the bone during any large strain or vigorous movements.
Bone Penetration
Images depicting bony in-growth
Immediate post-surgery
6 Weeks post-surgery
