Scientific Literature

This is a non-exhaustive list of scientific peer-reviewed articles published in international journals. These articles are directly related to the OPRA™ treatment, its development and continuous improvement.


Thesleff, A., Brånemark, R., Håkansson, B., Ortiz-Catalan, M. (2018). Biomechanical Characterisation of Bone-anchored Implant Systems for Amputation Limb Prostheses: A Systematic Review. Ann Biomed Eng, 46: 377. doi: Systematic review of bone-anchored implant systems for amputation limb prostheses focused on implant design.

Brånemark, R., Brånemark, P.-I., Rydevik, B., & Myers, R. R. (2001). Osseointegration in skeletal reconstruction and rehabilitation: A review. J Rehabil Res Dev, 38(2), 175–81.

Introduction to the osseointegration concept and its successful application in dental, maxillofacial, hearing aids, and limb prostheses.

Clinical outcomes

Li, Y., Kulbacka-Ortiz, K. Caine-Winterberger, K., Brånemark, R. (2019). Thumb amputations treated with osseointegrated percutaneous prostheses with up to 25 years of follow-up. doi: 10.5435/ JAAOSGlobal-D-18-00097

Long-term follow-follow up of thirteen thumb amputees who received osseointegrated prostheses (1990 to 2014), (median follow-up period was 9.5 years). Results: Six patients were lost to follow-up. Seven patients (including all six after the introduction of the standardized protocol) had good osseoperception, grip strength. Hand function was 94% of the normal hand. The most common complications were mechanical failures necessitating changes of components (eight times in three patients) and superficial infections (seven times in five patients). Five patients had no complications. The refined implant design and new standardized treatment protocol achieved a 100% cumulative success rate with 9.5 years of follow-up so far. Discussion: Treatment of thumb amputees using bone-anchored percutaneous prostheses seems to be a safe, durable method with excellent short- and medium-long follow-up results. Severe adverse events are few except for implant loosening which occurred only in the early custom-designed group.

Brånemark, R., Hagberg, K. Kulbacka-Ortiz, K., Berlin, Ö., Rydevik, B. (2018). Osseointegrated percutaneous prosthetic system for the treatment of patients with transfemoral amputation: A prospective five-year follow-up of patient-reported outcomes and complications. J Am Acad Orthop Surg, doi: 10.5435/JAAOS-D-17-00621

Prospective study in 51 transfemoral amputees with the OPRA™ Implant System. The cumulative fixture survival rate at 5 years was 92%, and the revision-free survival rate was 45%. Thirty-four patients had 70 superficial infections. Eleven patients had 14 deep infections. Fifteen patients had mechanical complications. Four fixtures were removed (ie, one deep infection and three loosening). Patient-reported (PRO) outcome measures showed significant improvements including more use of the prosthesis, better mobility, fewer issues, and improved physical health-related quality of life (all P < 0.0001) compared with baseline. Conclusion: Individuals with TFA at 5-year follow-up had significant improvement in PRO measures, but increases in deep infections and mechanical complications are concerning.

Li, Y., Lindeque, B. Percutaneous Osseointegrated Prostheses for Transfemoral Amputations. (2018). Orthopedics. 41(2):75–80. doi: 10.3928/01477447-20180227-03

Summarizing article describing patient evaluation, surgical technique, rehabilitation protocol and clinical outcomes based on 25 years of experience with bone-anchored amputation prostheses.

Li, Y. Brånemark, R. (2017). Osseointegrated prostheses for rehabilitation following amputation: The pioneering Swedish model. Unfallchirurg, doi: 10.1007/s00113-017-0331-4

Description of pioneering efforts on extremity osseointegration surgeries in Sweden and the development of the OPRA™ program. The standard implant design of the OPRA™ Implant system and surgical techniques are described as well as the special rehabilitation protocols for different amputation levels

Tillander, J., Hagberg, K. Berlin, Ö., Hagberg, L. Brånemark, R. (2017).Osteomyelitis risk in patients with transfemoral amputations treated with osseointegration prostheses. Clinical Orthopaedics and Related Research, doi: 10.1007/s11999-017-5507-2

Retrospective cohort study of the first 96 patients with transfemoral amputations selected for treatment with 102 (six bilateral) intramedullary transcutaneous titanium implants in Gothenburg, Sweden, between May 1990 and January 2010.

Brånemark, R., Berlin, Ö., Hagberg, K., Bergh, P., Gunterberg, B., & Rydevik, B. (2014). A novel osseointegrated, percutaneous prosthetic system for treatment of patients with transfemoral amputation: A prospective study of 51 patients. Bone Joint J, 96-B(1), 106–113.

Prospective study in 51 transfemoral amputees treated with the OPRA™ Implant System. The implant success rate was 92% at two years follow-up. Patients showed improved prosthetic use, mobility, and fewer problems as compared with socket prostheses. In average, patients had one superficial infection every other year, and these were treated with oral antibiotics. No superficial infection was found to develop into a deep bone infection. Improved quality of life was observed as result of treatment with the OPRA™ Implant System.

Hagberg, K., Hansson, E., & Brånemark, R. (2014). Outcome of percutaneous osseointegrated prostheses for patients with unilateral transfemoral amputation at two-year follow-up. Arch Phys Med Rehabil, 95, 2120-7.

Improvement of prosthetic function and physical quality of life was found on unilateral transfemoral amputees (TFA) treated with the OPRA™ Implant System. When compared with baseline, no significant changes were found in the use of walking aids and pain in back, shoulder or the contralateral limb. This was a prospective two-year case-control study on 39 unilateral TFA.

Tsikandylakis, G., Berlin, Ö., & Brånemark, R. (2014). Implant Survival, Adverse Events, and Bone Remodeling of Osseointegrated Percutaneous Implants for Transhumeral Amputees. Clinical Orthopaedics and Related Research. doi:10.1007/s11999-014-3695-6

Case series on osseointegrated limb prostheses at the transhumeral level. Eighteen patients were treated between 1995 and 2010, and the implant survival rate was 83% and 80% at 2 and 5 years, respectively. Age at implantation ranged between 19 and 69 years, and time since amputation was 1.5 to 33 years. The most common complication was superficial skin infections, which were treated with conventional oral antibiotics while the patients continue to use their prosthesis. No superficial infection progressed into a deep implant infection. Skin reactions were did not necessarily progress to infection. The majority of failures occurred within 2 years, after this period, the osseointegrated prostheses was stable for several years (up to 19 years).

Jönsson, S., Caine-Winterberger, K., & Brånemark, R. (2011). Osseointegration amputation prostheses on the upper limbs: methods, prosthetics and rehabilitation. Prosthet Orthot Int, 35(2), 190–200. doi:10.1177/0309364611409003

Introduction to the two-stage surgical procedure for osseointegrated prostheses, prosthetic components, and rehabilitation for upper extremities. Report on 10 thumbs, 1 partial hand, 10 transradial, and 16 transhumeral amputations treated with osseointegrated prostheses (OPRA™). The patients’ age at treatment ranged between 18 and 64 years, and the time since amputation ranged between 0 and 25 years. Patients indicated that functionality and their quality of life improved since osseointegration.

Frossard, L., Hagberg, K., Häggström, E., Gow, D. L., Brånemark, R., & Pearcy, M. (2010). Functional Outcome of Transfemoral Amputees Fitted With an Osseointegrated Fixation: Temporal Gait Characteristics. J Prosthet Orthot, 22(1), 11–20.

Study on gait characteristics between osseointegrated and socket transfemoral prostheses. Twelve subjects participated in this study that found a more normalized gait when using osseointegration (OPRA™) over socket. A higher functional level was found in osseointegrated patients. Gait using osseointegrated prosthesis did not equal that of an able-body control.

Hagberg, K., & Brånemark, R. (2009). One hundred patients treated with osseointegrated transfemoral amputation prostheses—rehabilitation perspective. J Rehabil Res Dev, 46(3), 331–344.

Description of the OPRA™ protocol as a treatment with osseointegrated prostheses. Report on one hundred patients treated before and after the establishment of the OPRA™ protocol. Most of the implant failures happen before the standardization of the treatment with the OPRA™ protocol. Cases with at least 7 years follow up were presented.

Hagberg, K., Brånemark, R., Gunterberg, B., & Rydevik, B. (2008). Osseointegrated trans-femoral amputation prostheses: prospective results of general and condition-specific quality of life in 18 patients at 2-year follow-up. Prosthet Orthot Int, 32(1), 29–41.

First prospective study on 18 transfemoral amputees (TFA) treated with osseointegrated prosthesis (OPRA™ Implant System). The implant success rate was 94% at two years follow up, with an improved health related quality of life. Increased prosthetic use, better mobility, fewer problems, and improved general amputation situation were found as compared with socket prostheses.

Sullivan, J., Uden, M., Robinson, K. P., & Sooriakumaran, S. (2003). Rehabilitation of the trans-femoral amputee with an osseointegrated prosthesis: the United Kingdom experience. Prosthet Orthot Int, 27(2), 114–20.

Experience in the United Kingdom with osseointegrated limb prostheses. The treatment of 11 transfemoral amputees is reported in this study. The first patient was treated in 1997 and reported functionality over 5 years. Two out of the eleven patients have their implant removed after one year owing to infection. Patients that successfully completed the program reported improvement in comfort, functionality, and quality of life.

Osseoperception – Improved sensory feedback via the OPRA Implant System

Häggström, E., Hagberg, K., Rydevik, B., & Brånemark, R. (2013). Vibrotactile evaluation: Osseointegrated versus socket-suspended transfemoral prostheses. J Rehabil Res Dev, 50(10), 1423–34.

The perception thresholds for vibratory and pressure stimuli were studied in 17 patients using socket prosthesis and then again two years after osseointegration. In comparison with socket prosthesis, patients showed better abilities to detect both types of stimuli after osseointegration, particularly at higher frequencies (125 Hz).

Lundborg, G., Waites, A., Björkman, A., Rosén, B., & Larsson, E.-M. (2006). Functional magnetic resonance imaging shows cortical activation on sensory stimulation of an osseointegrated prosthetic thumb. Scand J Plast Reconstr Surg Hand Surg, 40(4), 234–9.

Lundborg et al. studied cortical integration of osseointegrated thumb prosthesis using functional magnetic resonance imagining (fMRI). It was found that stimulation of the osseointegrated prosthesis activated the primary somatosensory cortex originally related to the biological thumb.

Jacobs, R., Brånemark, R., Olmarker, K., Rydevik, B., Steenberghe, D. Van, & Brånemark, P. (2000). Evaluation of the psychophysical detection threshold level for vibrotactile and pressure stimulation of prosthetic limbs using bone anchorage or soft tissue support. Prosthet Orthot Int, 24(2), 133–142.

Threshold levels for the perception of pressure and vibratory stimulati where investigated in 17 osseointegrated and 15 socket prosthesis. Patients wearing socket prosthesis required in average 20% higher stimulation threshold for vibration, while osseointegrated patients approach that of the healthy subjects. In regards to pressure, threshold increased to 60% and 40% in comparison with healthy subjects for socket and osseointegration, respectively. The authors concluded that patients treated with osseointegrated prosthesis (OPRA™) have higher perception via the prosthesis than socket users.

Social and psychological benefits of the OPRA™ Implant System

Lundberg, M., Hagberg, K., & Bullington, J. (2011). My prosthesis as a part of me: a qualitative analysis of living with an osseointegrated prosthetic limb. Prosthet Orthot Int, 35(2), 207–14.

Study on the patients’ experience of osseointegrated prosthesis as compared to socket suspension. Thirteen upper and lower limb amputees using osseointegrated prosthesis for 3 to 15 years were included. All participants described living with an osseointegrated prosthesis as revolutionary change. Patients reported the osseointegrated prosthesis as a more integral part of them, rather than an external tool. It improved self-confidence, reduced the perception of disability and allow them to engage in self-development.

Quotations from patients:

  • “The (osseointegrated) prosthesis makes me feel more whole as a person”
  •  “It’s much more integrated than it was with this old (socket) prostheses – it becomes a part of you
  • “No one questions today (after osseointegration) if I can do this or that, but everyone takes it for granted that I can do it… if we’re about to do something I never hear anyone asking ‘Do you think you can make it?’”
  • “I don’t think about having the prosthesis in that it doesn’t feel like a prosthesis. With this kind of technology (OI-prosthesis) you can’t feel it. I sit just as much on this leg as on the other leg and the scary thing was this week when I didn’t have my leg on, and when I suddenly stood up I felt I had on the prosthesis. It has come so far that the brain has also gradually begun to believe that I have a real leg”

Additional outcomes – OPRA™ Implant System

Tranberg, R., Zügner, R., Häggström, E., & Hagberg, K. (2014). Does osseointegrated transfemoral amputation prostheses increase the hip joint moment? Gait & Posture, 39S, S1–S141.

Increased moment of force developed due to walking on osseointegrated prostheses can be a naïve concern. This study found marginal differences in hip joint moment in 24 unilateral transfemoral amputees using osseointegration, as compared with their previous socket attachment. All joint moments were found comparable with those of 72 age- and gender-matched healthy controls.

Palmquist, A., Windahl, S. H., Norlindh, B., Brånemark, R., & Thomsen, P. (2014). Retrieved bone-anchored percutaneous amputation prosthesis showing maintained osseointegration after 11 years-a case report. Acta Orthopaedica, 85(3).

Case report on a fixture retrieved due to fracture. The patient was treated in 1993 and maintained osseointegration after 11 years as shown by scanning electron microscopy. The patient was successfully treated again with a new fixture.

Nebergall, A., Bragdon, C., Antonellis, A., Kärrholm, J., Brånemark, R., & Malchau, H. (2012). Stable fixation of an osseointegated implant system for above-the-knee amputees: titel RSA and radiographic evaluation of migration and bone remodeling in 55 cases. Acta Orthopaedica, 83(2), 121-8.

The long-term fixation of OPRA™ Implant System was demonstrated using radiostereometric analysis (RSA) and periprosthetic bone remodeling. At 5 years follow-up, no significant migration (0.02  mm) or rotation (0.42 degrees) was found in 55 implants.

Economic matters

Häggström, E. E., Hansson, E., & Hagberg, K. (2013). Comparison of prosthetic costs and service between osseointegrated and conventional suspended transfemoral prostheses. Prosthet Orthot Int, 37(2), 152–60.

Retrospective cost analysis of 50 patients treated with osseointegrated (20) and socket (36) prosthesis for an average of 10 years (6 patients used both types). The mean total annual cost of new prostheses, services, repairs and adjustments was 14% lower for osseointegrated patients, despite that these patients were provided with more sophisticated, and thus more expensive, prosthetic components for they could benefit more than socket users. Osseointegrated patients required approximately 50% less visits to the prosthetic workshop.

New technologies based on the OPRA Implant System

Ortiz-Catalan, M., Håkansson, B., & Brånemark, R. (2014). An osseointegrated human-machine gateway for long-term sensory feedback and motor control of artificial limbs. Science Translational Medicine, 6(257), 257re6.

Long-term results of the first implementation of neural prosthetic control using implanted neuromuscular interfaces and osseointegration. For the first time, implanted neuromuscular electrodes were used the control of a prosthetic limb in activities of the daily living stably for over a year. It was demonstrated that this system provided a more precise and reliable control than surface electrodes, regardless of limb position and environmental conditions, and with less effort. Furthermore, long-term stable myoelectric pattern recognition and appropriate sensory feedback elicited via neurostimulation was demonstrated.

Brånemark, R., Emanuelsson, L., Palmquist, A., & Thomsen, P. (2011). Bone response to laser-induced micro- and nano-size titanium surface features. Nanomedicine, 7(2), 220–7. doi:10.1016/j.nano.2010.10.006

Study on the effect of surface modifications (micro- and nano-scale) on bone formation. An increase of 250% removal torque was found in laser-modified osseointegrated implants in a rabbit model.

Other clinically successful applications of percutaneous osseointegrated implants

Dun, C. A. J., Faber, H. T., de Wolf, M. J. F., Mylanus, E. A. M., Cremers, C. W. R. J., & Hol, M. K. S. (2012). Assessment of more than 1,000 implanted percutaneous bone conduction devices: skin reactions and implant survival. Otology & Neurotology, 33(2), 192–8.

This study reports on 7,415 observations of 1,132 percutaneous implants for bone conducting devices. No adverse soft tissue reactions were found in 95.5% of the observations in 4.6 years.

Brånemark, P.-I., Hansson, B. O., Adell, R., Breine, U., Lindström, J., Hallen, O., & Öhman, A. (1977). Osseointegrated implants in the treatment of the edentulous jaw. Scand J Plast Reconstr Surg Suppl, 16, 1–132.

Clinical Evidence on Phantom Motor Execution as a treatment for Phantom Limb Pain

Ortiz-Catalan M, Sander N, Kristoffersen MB, Håkansson B, Brånemark R. Treatment of phantom limb pain (PLP) based on augmented reality and gaming controlled by myoelectric pattern recognition : a case study of a chronic PLP patient. Front Neurosci. (2014) 8:24. 10.3389/fnins.2014.00024

Ortiz-Catalan M, Guð*mundsdóttir RA, Kristoffersen MB, Zepeda-Echavarria A, Caine-Winterberger K, Kulbacka-Ortiz K, et al. . Phantom motor execution facilitated by machine learning and augmented reality as treatment for phantom limb pain: a single group, clinical trial in patients with chronic intractable phantom limb pain. Lancet (2016) 388:2885–94. 10.1016/S0140-6736(16)31598-7

Lendaro, E., Hermansson, L., Burger, H., van der Sluis, C. K., McGuire, B. E., Pilch, M., … Ortiz-Catalan, M. (2018). Phantom motor execution as a treatment for phantom limb pain : protocol of an international, double-blind, randomised controlled clinical trial. BMJ Open, 8(7).

Ortiz-Catalan M. (2018). The Stochastic Entanglement and Phantom Motor Execution Hypotheses: A Theoretical Framework for the Origin and Treatment of Phantom Limb Pain. Frontiers in neurology9, 748. doi:10.3389/fneur.2018.00748