Association Between Osseointegration of Lower Extremity Amputation and Mortality Among Adults

Breaking Barriers-The Promise and Challenges of Limb Osseointegration Surgery

Limb amputation remains a significant global health issue, affecting millions of individuals annually. A substantial proportion of these patients struggle with the inadequate fit and discomfort of conventional prosthetic sockets, leading to diminished quality of life. Osseointegration surgery, a promising alternative, offers the direct skeletal attachment of bone, implant, and prosthetic, providing a more stable and functional interface. Osseointegration remains an emerging procedure, and while exact global figures are difficult to pinpoint, estimates suggest that over 10,000 patients worldwide have received osseointegration implants since the technique was first introduced. This perspective article analyzes recent advancements in the field of limb osseointegration, highlighting key achievements such as improved implant materials, surgical techniques, and comprehensive prosthetic integration strategies. Additionally, it explores future directions for development and discusses the latest research trends shaping the evolution of this field. Despite these developments, the widespread adoption of osseointegration faces significant barriers, including complications, limited access to multidisciplinary care, economic constraints, and the need for further long-term clinical evidence. In this paper, we present an extensive perspective on the current state of osseointegration, discuss the challenges impeding its broader implementation, and offer recommendations to address these obstacles, with the goal of enhancing patient outcomes and facilitating the integration of osseointegration into mainstream clinical practice.

Consensus statement on the prevention, diagnosis, and management of infection following transcutaneous osseointegration for patients with limb loss: current state-of-the-art and proposed future studies

The diagnosis, risk factors, treatment algorithms, and long-term sequelae of superficial and deep, implant-related infections in transdermal, bone-anchored osseointegration are not well-defined. In contrast to the robust experience diagnosing and managing periprosthetic joint infections in total joint arthroplasty, osseointegration surgery has only recently been adopted at a small number of osseointegration centers in the United States, contributing to the lack of long-term outcomes. Through the pooled experience from these osseointegration centers, we present a consensus statement on the perioperative management, incidence, treatment, and diagnostic workup for infectious complications following transdermal, bone-anchored osseointegration.

How To Improve Patient Selection in Individuals With Lower Extremity Amputation Using a Bone-anchored Prosthesis

BACKGROUND

Many patients with a lower limb socket-suspended prothesis experience socket-related problems, such as pain, chronic skin conditions, and mechanical problems, and as a result, health-related quality of life (HRQoL) is often negatively affected. A bone-anchored prosthesis can overcome these problems and improve HRQoL, but these prostheses have potential downsides as well. A valid and reliable tool to assess potential candidates for surgery concerning a favorable risk-benefit ratio between potential complications related to bone-anchored prostheses and improvements in HRQoL is not available yet. Having this information may inform treating physicians and patients when deciding whether to pursue bone-anchored prostheses.

QUESTIONS/PURPOSE

In this study, we asked: (1) What is the difference in HRQoL at 6, 12, and 24 months among patients who underwent lower limb bone-anchored prosthesis treatment after using a socket-suspended prosthesis preoperatively? (2) What factors are associated with change in HRQoL 24 months after lower limb bone-anchored prosthesis treatment? (3) Which complications occurred within 24 months after lower limb bone-anchored prosthesis treatment? (4) What factors are associated with minor to severe complications within 24 months after lower limb bone-anchored prosthesis treatment?

METHODS

A total of 206 patients who underwent lower limb bone-anchored prosthesis treatment (femoral or tibial) at the Radboud University Medical Center between May 2014 and September 2020 were included in this study. Of those, 8% (17 of 206) were lost to follow-up at 24 months without meeting a study endpoint (not attending the clinic unrelated to the bone-anchored prosthesis, re-amputation), and another < 1% (1 of 206) died prior to 24 months, leaving 92% (189 of 206) of the original group who had a follow-up time of at least 24 months. The mean ± SD age was 54.3 ± 12.7 years, and 72% were men. Amputation levels included 64% (139 of 218) transfemoral amputation, 3% (7 of 218) knee exarticulation, 32% (70 of 218) transtibial amputation, 0.5% (1 of 218) foot amputation, and 0.5% (1 of 218) osseointegration implant after primary amputation. Causes of amputation included 52% (108 of 206) trauma, 8% (17 of 206) oncology, 19% (38 of 206) dysvascular, 12% (25 of 206) infection, 1% (2 of 206) congenital, and 8% (16 of 206) other. Primary outcomes were generic HRQoL (Short-Form 36 health survey mental component summary [MCS] and physical component summary [PCS] scores), disease-specific HRQoL (Questionnaire for Persons with a Transfemoral Amputation global score), and complication occurrence (infection, implant complications such as loosening or breakage, stoma-related problems, periprosthetic fracture, and death). Multivariable multiple regression was used to develop association models. These models demonstrated which group of characteristics were associated with change in HRQoL at 24 months of follow-up and occurrence of complications within 24 months of follow-up. Assessments were carried out at baseline (preoperative while using a socket-suspended prosthesis) and after 6, 12, and 24 months of bone-anchored prosthesis use.

RESULTS

Generic HRQoL PCS score improved 25% (β 9 [95% confidence interval (CI) 7 to 11]) at 6 months and maintained that improvement at the 12-month (β 9 [95% CI 7 to 11]) and 24-month (β 8 [95% CI 7 to 10]) follow-up visit compared with baseline (p < 0.001). The generic HRQoL MCS score did not change compared with baseline. Disease-specific HRQoL improved 77% (β 30 [95% CI 25 to 34]), 85% (β 33 [95% CI 28 to 37]), and 72% (β 28 [95% CI 24 to 33]) at 6-month, 12-month, and 24-month follow-up, respectively, compared with baseline (p < 0.001). Patients with the following group of characteristics were more likely to experience a better physical generic HRQoL at 24 months of follow-up: younger patients with a lower physical generic HRQoL, and a traumatic cause of amputation combined with a lower activity level. Patients with the following group of characteristics were more likely to experience a better disease-specific HRQoL at 24 months of follow-up: dysvascular cause of amputation, lower prosthetic comfort combined with a lower activity level, and lower prosthetic comfort combined with a lower or higher activity level. In addition, patients with an average mobility level were more likely to experience less improvement in disease-specific HRQoL at 24 months of follow-up. Infections were the most common complications in the total cohort (116 events in 206 patients), of which the majority consisted of soft tissue infections (98% [114 of 116]). Bone infection did not occur. Septic implant loosening occurred in 1% (2 of 214) of total implants (3% [2 of 66] of tibial implants), both treated with transfemoral amputation. Younger and higher functioning patients had the lowest risk of minor complications within 24 months of follow-up. Women, older patients, patients with a lower activity level, and older patients with more time since amputation had the highest risk of minor complications within 24 months of follow-up. Patients with a higher disease-specific HRQoL had the highest risk of moderate or severe complications within 24 months of follow-up.

CONCLUSION

In agreement with earlier research, this study confirmed that generic HRQoL and disease-specific HRQoL improved after bone-anchored prosthesis use. Additionally, this study confirmed that bone-anchored prosthesis has a relatively low likelihood of severe complications but with a high occurrence of minor complications. These were often successfully treated with nonsurgical interventions. Patients who have a favorable risk-benefit ratio between improvements in HRQoL and potential treatment-related complications are most eligible for a bone-anchored prosthesis. These findings may be helpful to patients and treating physicians to aid in patient selection and to inform patients about potential short-term expectations of treatment.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Lower Extremity Osseointegration Postoperative Rehabilitation Protocols: A Scoping Review

OBJECTIVE

Lower-extremity transcutaneous osseointegration is a rehabilitation alternative to socket-suspended prostheses. The rehabilitation process, philosophies, and routines remain under-described. This review, primarily, identifies commonalities and differences among protocols. Secondarily, strategies are proposed to streamline future research of post-osseointegration surgery rehabilitation.

METHODS

Two differently-phrased queries of Google Scholar, Pubmed, Embase, and Web of Science were performed. First using either "osseointegration" or "osseointegrated" or "bone anchored prosthesis" AND [last name]. Second, replacing author name with "physical therapy" or "rehabilitation". Six hundred eighty-eight articles were identified describing lower-extremity rehabilitation following osseointegration. Following software-based deduplication, manual abstract and full-text review, article reference evaluation, and use of Google Scholar's "Cited by" feature, 35 studies were fully analyzed. First, a consolidated summary was made of protocols focusing on stages, timing, and other descriptions of postoperative rehabilitation. Subsequently, strengths and limitations of protocols were considered to propose potential strategies to investigate and optimize postoperative rehabilitation.

RESULTS

All articles describe rehabilitation having this same order of goal progression: from surgery to gradual weight bearing and final goal of independent ambulation. The most impactful difference influencing the stated final goal of independent ambulation was whether one or two surgical stages were performed. No articles reported patient success rate achieving proposed goals and timing, or challenges during rehabilitation. Therefore, the first research suggestion is to investigate actual success rates achieving proposed goals and timing. Second, to further explore rehabilitation of performance deficits, beyond unaided ambulation. Finally, to incorporate technology such as mobility trackers to more objectively understand prosthesis use and mobility.

CONCLUSION

All lower-extremity osseointegration rehabilitation literature recommends identical goal progression order. No studies evaluate patient challenges or variation. Understanding and addressing such challenges may enhance postoperative rehabilitation.

IMPACT

This article consolidates published rehabilitation protocols post-osseointegration surgery. Specific analysis and experimentation of the protocols may enhance the uniformity and potential of patient rehabilitation.

Amputation Surgery: Review of New and Emerging Techniques

Major upper and lower extremity amputations are increasingly being performed for peripheral vascular disease, infectious etiologies, trauma, and oncologic purposes. Attention to technique and emerging treatments for the residual peripheral nerve is critical to prosthetic wear and quality of life following these life changing events. Here, we detail advancements in amputation surgery including targeted muscle reinnervation, regenerative peripheral nerve interface, and the use of osseointegrated implants.

Use of blood parameters for the prediction of mortality in patients with below‑knee amputation

The present retrospective study aimed to investigate the value of blood parameters in predicting mortality in patients with below-knee amputation (BKA). A total of 178 patients with BKA were included in the present study. The patients were divided into two groups, namely the exitus group (n=136; 76.4%) and the survivors group (n=42; 23.6%). Patients in the exitus group were further divided into three subgroups: i) Those who experienced mortality in <1 month (n=55; 40.4%); ii) those who experienced mortality between 1-12 months (n=48; 35.3%); and iii) those who experienced mortality in >12 months after surgery (n=33; 24.3%). Binary logistic regression and a generalized linear model were used for relational analysis, and a receiver operator characteristic curve was used for diagnostic tests. It was found that the parameters of age (B=0.061; P=0.01), eosinophil-to-lymphocyte ratio (ELR) (B=-2.861; P<0.05), C-reactive protein (CRP)/albumin ratio (B=0.027; P<0.01) and mean platelet volume (MPV)/lymphocyte ratio (B=0.310; P<0.01) had a significant effect on mortality at the multivariate level. Moreover, regression coefficients showed that the effect of age, CRP/albumin and MPV/lymphocyte ratios on mortality were positive, whereas the effect of the ELR was negative. The mortality predictive values of age [area under the curve (AUC)=0.681; P=0.01], ELR (AUC=0.630; P=0.01), CRP/albumin ratio (AUC=0.746; P=0.01) and MPV/lymphocyte ratio (AUC=0.676; P<0.01) were also found to be statistically significant. For the 27.51 CRP/albumin cut-off value, the sensitivity was found to be 80.1%, whereas the specificity was 54.8%. For the 36.93 CRP/albumin cut-off value, the sensitivity was 71.3%, and the specificity was 73.8%. Furthermore, MPV (B=-0.37; P<0.01) and hemoglobin/red-blood-cell distribution width (RDW) ratio (B=5.20; P<0.01) were found to have a significant effect on the time to death at the multivariate level. The parameters MPV (AUC=0.648; P<0.01) and hemoglobin/RDW (AUC=0.673; P=0.01) had predictive value in terms of the time to death. The predictive value for MPV was found to be 64.8%, whereas that for the hemoglobin/RDW ratio was 67.3%. For the 0.54 cut-off value for hemoglobin/RDW, the sensitivity was 74.5%, and the specificity was 11.1%. By contrast, for the 0.84 cut-off value for the hemoglobin/RDW ratio, the sensitivity was 10.9% and the specificity was 81.5%. In conclusion, the CRP/albumin ratio was identified as a significant mortality parameter, whereas the hemoglobin/RDW ratio was a significant time to death predictor, according to the results of the present analysis. These results may guide clinical practices and further research in terms of predicting mortality in patients with BKA.

Transfemoral Osseointegration in Association With Total Hip Replacement: Observational Cohort Study of Patients With Follow-Up Exceeding 2 Years

Background

Some amputees with transfemoral osseointegration (TFOI) have ipsilateral hip arthritis which can be addressed with total hip arthroplasty (THA). This study reported the medium-term outcomes of THA in association with TFOI (THA + TFOI).

Methods

Retrospective review was performed for eight patients with THA + TFOI performed at least 2 years prior. Primary outcomes include complications prompting surgical intervention. Secondary outcomes include changes in mobility (K-level, 6-minute walk test [6MWT], timed up and go) and patient-reported measures (hip pain, daily prosthesis wear hours, Questionnaire for Persons with a Transfemoral Amputation, and Short Form 36 [SF36]).

Results

One patient died after 11 months (cancer); he was included to maximally report complications but excluded from mobility and reported outcomes. Three patients required subsequent surgeries: Two had skin refashioning, and the other underwent hip debridement of the replaced joint with subsequent removal of the TFOI. No perioperative complications, fractures, or arthroplasty explantations occurred. All patients reported complete hip pain relief. Of 6 patients reporting prosthesis wear time, 2 (33%) wore their prosthetic leg at least 4 hours daily before, vs all (100%) who did afterward (P = .061). K-levels improved in all responding patients. All 5 wheelchair-bound patients achieved and maintained ambulation. The Questionnaire for Persons with a Transfemoral Amputation and Short Form 36 did not significantly change.

Conclusions

THA + TFOI does not appear to pose an inevitable risk for prosthetic hip infection and may improve mobility and enhance quality of life (QOL) for transfemoral amputees with concurrent arthritic hip pain who are dissatisfied with their outcome following traditional socket prosthesis rehabilitation.

Transtibial osseointegration following unilateral traumatic amputation: An observational study of patients with at least two years follow-up

IMPORTANCE

Most patients use a traditional socket prosthesis (TSP) to ambulate independently following transtibial amputation. However, these patients generally require prosthesis repairs more than twice annually and an entirely new prosthesis every two years. Furthermore, transtibial amputation patients have four times the skin ulceration rate of transfemoral patients, prompting more frequent prosthesis refitting and diminished use. Trans-Tibial osseointegration (TTOI) is a promising technique to address the limitations of TSP, but remains understudied with only four cohorts totaling 41 total procedures reported previously. Continued concerns regarding the risk of infection and questions as to functional capacity postoperatively have slowed adoption of TTOI worldwide.

OBJECTIVE

This study reports the changes in mobility, quality of life (QOL), and the safety profile of the largest described cohort of patients with unilateral TTOI following traumatic amputation.

DESIGN

Retrospective observational cohort study. The cohort consisted of patients with data outcomes collected before and after osseointegration intervention.

SETTING

A large, tertiary referral, major metropolitan center.

PARTICIPANTS

Twenty-one skeletally mature adults who had failed socket prosthesis rehabilitation, with at least two years of post-osseointegration follow-up.

MAIN OUTCOMES AND MEASURES

Mobility was evaluated by K-level, Timed Up and Go (TUG), and Six Minute Walk Test (6MWT). QOL was assessed by survey: daily prosthesis wear hours, prosthesis problem experience, general contentment with prosthesis, and Short Form 36 (SF36). Adverse events included any relevant unplanned surgery such as for infection, fracture, implant loosening, or implant failure.

RESULTS

All patients demonstrated statistically significant improvement post osseointegration surgery with respect to K-level, TUG, 6MWT, prosthesis wear hours, prosthesis problem experience, general prosthesis contentment score, and SF36 Physical Component Score (p < 0.01 for all). Three patients had four unplanned surgeries: two soft tissue refashionings, and one soft tissue debridement followed eventually by implant removal. No deaths, postoperative systemic complications, more proximal amputations, or periprosthetic fractures occurred.

CONCLUSIONS AND RELEVANCE

TTOI is likely to confer mobility and QOL improvements to patients dissatisfied with TSP rehabilitation following unilateral traumatic transtibial amputation. Adverse events are relatively infrequent and not further disabling. Judicious use of TTOI seems reasonable for properly selected patients.

LEVEL OF EVIDENCE

2 (Therapeutic investigation, Observational study with dramatic effect).

Bone-anchored prostheses for transfemoral amputation: a systematic review of outcomes, complications, patient experiences, and cost-effectiveness

Introduction

Bone-anchored prostheses (BAP) are an advanced reconstructive surgical approach for individuals who had transfemoral amputation and are unable to use the conventional socket-suspension systems for their prostheses. Access to this technology has been limited in part due to the lag between the start of a new procedure and the availability of evidence that is required before making decisions about widespread provision. This systematic review presents as a single resource up-to-date information on aspects most relevant to decision makers, i.e., clinical efficacy, safety parameters, patient experiences, and health economic outcomes of this technology.

Methods

A systematic search of the literature was conducted by an information specialist in PubMed, MEDLINE, Embase, CINAHL, Cochrane Library, the Core Collection of Web of Science, CADTH's Grey Matters, and Google Scholar up until May 31, 2023. Peer-reviewed original research articles on the outcomes of clinical effectiveness (health-related quality of life, mobility, and prosthesis usage), complications and adverse events, patient experiences, and health economic outcomes were included. The quality of the studies was assessed using the Oxford Centre for Evidence-Based Medicine Levels of Evidence and ROBINS-I, as appropriate.

Results

Fifty studies met the inclusion criteria, of which 12 were excluded. Thirty-eight studies were finally included in this review, of which 21 reported on clinical outcomes and complications, 9 case series and 1 cohort study focused specifically on complications and adverse events, and 2 and 5 qualitative studies reported on patient experience and health economic assessments, respectively. The most common study design is a single-arm trial (pre-/post-intervention design) with varying lengths of follow-up.

Discussion

The clinical efficacy of this technology is evident in selected populations. Overall, patients reported increased health-related quality of life, mobility, and prosthesis usage post-intervention. The most common complication is a superficial or soft-tissue infection, and more serious complications are rare. Patient-reported experiences have generally been positive. Evidence indicates that bone-anchored implants for prosthesis fixation are cost-effective for those individuals who face significant challenges in using socket-suspension systems, although they may offer no additional advantage to those who are functioning well with their socket-suspended prostheses.

Infection After Lower-Limb Osseointegration: A Single-Center Retrospective Evaluation of Pathogens, Management, and Outcomes

PURPOSE

Osseointegration (OI) is a novel alternative to traditional socket-suspended prostheses for lower-limb amputees, eliminating the socket-skin interface and allowing for weight bearing directly on the skeletal system. However, the stoma through which the implant attaches to the external prosthesis creates an ingress route for bacteria, and infection rates as high as 66% have been reported. The aims of this study are to classify infection management and long-term outcomes in this patient population to maximize implant salvage.

METHODS

An institutional review board-approved retrospective analysis was performed on all patients who underwent lower-limb OI at our institution between 2017 and 2022. Demographic, operative, and outcome data were collected for all patients. Patients were stratified by the presence and severity of infection. Chi-square and t tests were performed on categorical and continuous data, respectively, using an alpha of 0.05.

RESULTS

One hundred two patients met our study criteria; 62 had transfemoral OI and 40 had transtibial OI. Patients were followed for 23.8 months on average (range, 3.5-63.7). Osteomyelitis was more likely than soft tissue infection to be polymicrobial in nature (71% vs 23%, P < 0.05). Infections at the stoma were mostly (96%) managed with oral antibiotics alone, whereas deeper soft tissue infections also required intravenous antibiotics (75%) or operative washout (19%). Osteomyelitis was managed with intravenous antibiotics and required operative attention; 5 (71%) underwent washout and 2 (29%) underwent explantation. Both implants were replaced an average of 3.5 months after explantation. There was no correlation between history of soft tissue infection and development of osteomyelitis (P > 0.05). The overall implant salvage rate after infection was 96%.

CONCLUSIONS

This study describes our institution's experience managing infection after OI and soft tissue reconstruction. Although infections do occur, they are easily treatable and rarely require operative intervention. Explantation due to infection is rare and can be followed up with reimplantation, reaffirming that OI is a safe and effective treatment modality.

Lifetime cost-effectiveness analysis osseointegrated transfemoral versus socket prosthesis using Markov modelling

Aims

Prior cost-effectiveness analyses on osseointegrated prosthesis for transfemoral unilateral amputees have analyzed outcomes in non-USA countries using generic quality of life instruments, which may not be appropriate when evaluating disease-specific quality of life. These prior analyses have also focused only on patients who had failed a socket-based prosthesis. The aim of the current study is to use a disease-specific quality of life instrument, which can more accurately reflect a patient's quality of life with this condition in order to evaluate cost-effectiveness, examining both treatment-naïve and socket refractory patients.

Methods

Lifetime Markov models were developed evaluating active healthy middle-aged male amputees. Costs of the prostheses, associated complications, use/non-use, and annual costs of arthroplasty parts and service for both a socket and osseointegrated (OPRA) prosthesis were included. Effectiveness was evaluated using the questionnaire for persons with a transfemoral amputation (Q-TFA) until death. All costs and Q-TFA were discounted at 3% annually. Sensitivity analyses on those cost variables which affected a change in treatment (OPRA to socket, or socket to OPRA) were evaluated to determine threshold values. Incremental cost-effectiveness ratios (ICERs) were calculated.

Results

For treatment-naïve patients, the lifetime ICER for OPRA was $279/quality-adjusted life-year (QALY). For treatment-refractory patients the ICER was $273/QALY. In sensitivity analysis, the variable thresholds that would affect a change in the course of treatment based on cost (from socket to OPRA), included the following for the treatment-naïve group: yearly replacement components for socket > $8,511; cost yearly replacement parts OPRA < $1,758; and for treatment-refractory group: yearly replacement component for socket of > $12,467.

Conclusion

The use of the OPRA prosthesis in physically active transfemoral amputees should be considered as a cost-effective alternative in both treatment-naïve and treatment-refractory socket prosthesis patients. Disease-specific quality of life assessments such as Q-TFA are more sensitive when evaluating cost-effectiveness.

Complications Following Osseointegrated Transfemoral and Transtibial Implants: A Systematic Review

Lower limb amputation is a common orthopedic surgery in the United States and can be performed either above or below the knee. Prosthetics are typically externally fitted to the patient's residual stump; however, osseointegrated implants offer a potential alternative to this process. Transcutaneous limb osseointegration involves the intramedullary anchoring of an implant that can later attach to a prosthetic via a stoma in the residual limb. There are proposed benefits to this, including decreased skin and soft tissue complications as well as an increased sense of stability. As this is a relatively new procedure, the complications and efficacy are not well supported by the literature at this time. The primary aim of this analysis was to synthesize the currently available data on transfemoral and transtibial osseointegration in order to improve our understanding of the potential complications of the procedure. A literature search was performed in the following databases: Biomedical Reference Collection, CINAHL, Cochrane Library, and PubMed/MEDLINE. Articles were screened by three independent reviewers for studies written or available in English, study design, and study outcomes, including complications. No filter was applied for publication date, publication national origin, or sample size. A total of 20 articles were selected for the final qualitative analysis. This review demonstrates an overall low or non-inferior rate of both minor and severe complications in transtibial and transfemoral osseointegration. This procedure should be considered as an option during preoperative planning in the context of above-the-knee and below-the-knee amputations. However, continued studies with larger sample sizes and extended postoperative follow-up are necessary for a greater strength of recommendation.

Transfemoral amputation versus knee arthrodesis for failed total knee replacement: A systematic review of outcomes

BACKGROUND

The options available to salvage a failed total knee replacement (TKR) include transfemoral amputation (TFA) and knee arthrodesis (KA). This systematic review aims to evaluate outcomes following either TFA or KA, comparing ambulatory status, additional subsequent surgery, postoperative infection, pain, health-related quality of life (HRQoL), and mortality rate.

METHODS

A literature search was conducted in EMBASE, Ovid Medline, and PubMed. Only primary research studies were included and data were independently extracted using a standardized form. The methodological quality of the studies was evaluated using Newcastle-Ottawa Scale.

RESULTS

Forty-four papers were included, comprising 470 TFA and 1034 KA patients. The methodological quality of the studies was moderate. No TFA versus KA randomized controlled trials could be identified. Pooled data totals via subgroup analyses were performed, owing to inconsistent reporting methods in the included studies. Prosthesis use rate by TFA patients was 157/316 = 49.7%. Significant differences included that TFA patients had lower rates of ambulatory capacity than KA patients (139/294 = 45.6% versus 248/287 = 86.4%, p < 0.001), TFA ambulators were less likely to use an ambulatory aid (55/135 = 40.7% versus 167/232 = 72.0%, p < 0.001), and TFA was associated with a greater postoperative infection rate than KA (29/118 = 24.6% versus 129/650 = 17.2%, p = 0.054). There was a similar rate of revision surgery between TFA and KA (37/183 = 20.2% versus 145/780 = 18.6%, p = 0.612). Data on HRQoL for both TFA and KA were limited, contradictory, and heterogeneous.

CONCLUSION

No randomized controlled trials comparing TFA versus KA exist;therefore, current data likely reflects substantial selection bias. The currently available evidence suggests that KA patients are significantly more likely to achieve independent bipedal ambulation than TFA patients. In both treatment cohorts, subsequent infection and revision surgery remain a relatively common occurrence.

Development of an evidence-based diagnostic algorithm for infection in patients with transcutaneous osseointegration following amputation

Introduction: Transcutaneous osseointegration following amputation (TOFA) confers better mobility and quality of life for most patients versus socket prosthesis rehabilitation. Peri-TOFA infection remains the most frequent complication and lacks an evidence-based diagnostic algorithm. This study's objective was to investigate preoperative factors associated with positive intraoperative cultures among patients suspected of having peri-TOFA infection in order to create an evidence-based diagnostic algorithm. Methods: We conducted a retrospective study of 83 surgeries (70 patients) performed to manage suspected lower-extremity peri-TOFA infection at a specialty orthopedic practice and tertiary referral hospital in a major urban center. The diagnosis of infection was defined as positive intraoperative cultures. Preoperative patient history (fevers, subjective pain, increased drainage), physician examination findings (local cellulitis, purulent discharge, implant looseness), and laboratory data (white blood cell count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and external swab culture) were evaluated for association with subsequent positive intraoperative cultures using regression and area under receiver-operator curve (AUC) modeling. Results: Peri-implant limb pain (highly correlated with infection), ESR > 30 (highly correlated against infection), positive preoperative swab (moderately correlated with infection), gross implant motion (moderately correlated against infection), and erythema or cellulitis of the transcutaneous region (mildly correlated with infection) were variables included in the best AUC model, which achieved an 85 % positive predictive value. Other clinical findings and laboratory values (notably CRP and WBC) were non-predictive of infection. Conclusions: This seminal investigation to develop a preoperative diagnostic algorithm for peri-TOFA infection suggests that the clinical examination remains paramount. Further evaluation of a wider spectrum of clinical, laboratory, and imaging data, consistently and routinely collected with prospective data techniques in larger cohorts of patients, is necessary to create a robust predictive algorithm.

Techniques to Remove Press-Fit Osseointegration Implants

Background

Transcutaneous osseointegration for amputees (TOFA) has proven to consistently, significantly improve the quality of life and mobility for the vast majority of amputees, as compared with the use of a socket prosthesis1,2. As with any implant, situations such as infection, aseptic loosening, or implant fracture can occur, which may necessitate hardware removal. Although it may eventually occur, to date no osseointegration implant has ever required removal in the setting of periprosthetic fracture. Since TOFA implants are designed to facilitate robust bone integration, removal can be challenging. Even in cases in which portions of the implant are loose, other areas of the implant may remain strongly integrated and resist removal. Further, there can be cases in which an implant fractures, leaving the residual portion of the implant in place without the interface for an extraction tool. Although the outcomes of revision osseointegration has not been the primary focus of any publication, the fact that revision can be necessary and generally succeeds in restoring similar mobility has been documented3-5. As with any hardware removal, preserving healthy tissue and avoiding iatrogenic injury are critically important. This article demonstrates several techniques to remove press-fit osseointegration implants that we have found safe and effective.

Description

The procedure is performed with the patient in the supine position and with the affected extremity prepared and draped in a typical sterile fashion. The use of a tourniquet can help reduce blood loss, but it may be safer to not use a tourniquet during the portions of the procedure that create increased or prolonged bone thermal exposure, such as during reaming or drilling. If patients are clinically stable, withholding antibiotics until cultures are obtained may improve diagnostic yield. The implant removal technique should proceed from conservative to aggressive, as necessary: slap hammer, thin wire-assisted slap hammer, and extended osteotomy. Trephine reaming is discouraged because of the need for and difficulty of removing the dual cone interface portion of the implant, along with the extensive damage often caused to the surrounding bone during reaming, which can be avoided with the osteotomy technique.

Alternatives

It is important to emphasize that most infections related to transcutaneous osseointegration do not require implant removal; the use of antibiotics alone or soft-tissue and/or limited bone debridement is sufficient to resolve infection in the majority of cases. If a patient has a non-infectious indication for removal (such as a loose implant) but declines surgery, activity modification with close observation may be reasonable. If a patient has an infectious indication for removal but declines surgery, very close observation must be maintained to avoid potential osteomyelitis. The use of suppressive antibiotics (oral and/or intravenous) may help reduce the severity of the infection. An alternative surgery to manage implant-associated infection can be amputation above the implant (within the same bone, through-joint amputation, or through the femur for a transtibial osseointegration). This should be considered only if there is a tremendously compelling reason to do so, such as an emergency need to amputate due to a life-threatening infection.

Rationale

Indications for implant removal include persistent pain, deep infection recalcitrant to soft-tissue or bone debridement and implant retention, or mechanical complications involving the implant, such as loosening or breakage. The following are specific examples of indications for removal: infection that cannot be resolved with oral and/or intravenous antibiotics or with debridement of soft tissue and/or bone, implants that have not achieved or not maintained stable integration (aseptic or loosening) and are causing pain, and implants that have fractured or have deformed and are a concern for fracture.

Expected Outcomes

Most patients who require removal of press-fit osseointegration implants are suitable for reimplantation after a decontamination period involving a local antibiotic depot and intravenous antibiotics. This duration is often 6 to 12 weeks. Following revision osseointegration, patients generally achieve similar levels of performance as they had during the stable period prior to removal3-5. Infection does not appear to be associated with an increased risk of mortality6. Patients who decline revision osseointegration are able to return to the use of a socket prosthesis.

Important Tips

Infection is often treatable with use of oral and/or intravenous antibiotics, with or without soft-tissue and/or bone debridement. Consider these options before reflexively removing an implant.Preserving bone stock and quality is important for an optimal revision to another osseointegration prosthesis or conversion to a socket prosthesis. Living bone, even if infected, can be decontaminated with antibiotics. Minimize thermal injury by releasing the tourniquet and using saline solution irrigation during reaming or similar portions of the procedure. If the implant can only be removed by fully removing a portion of bone (rather than through a single clamshell-type osteotomy), attempt screw osteosynthesis to preserve a canal for future osseointegration.Be gentle and patient during the removal techniques. Elevating bone quickly or violently may cause propagating fractures, increased morbidity, or splinter bone fragments. Carefully separating bone from implant will reduce bone loss and preserve the bone condition for a potential revision.Although patients may not appear to have an infection in some cases, it is advised to treat every removal as if it involves an infection. The first surgical stage should be for removal, culture acquisition, and decontamination with antibiotics. A separate second surgery can be performed after the antibiotics have eradicated infection.Many implants have been removed with slap hammer or fine wire techniques; osteotomy should be reserved for situations in which diligent attempts using these techniques have proven unsuccessful, in order to optimize bone integrity.

Modern Internet Search Analytics and Osseointegration: What are Patients Asking and Reading Online?

Background

Osseointegration (OI) limb has been performed for over 30 years and is an example of an advance in technology and surgical technique which has led to improvements in patient mobility and quality of life. An increasing number of patients seek information about osseointegration. The aim of this study was to categorise the most frequently asked questions by patients using the Google search engine and the most frequently accessed websites with the highest return on answers. The secondary aims of this study were to assess the quality of the information provided on those websites and to stratify, by category, which websites provide the best quality information.

Materials and methods

Ten permutations and conjugations of the word 'osseointegration' were entered into Google. The first fifty 'People also ask' and associated websites by Google's machine learning and natural language processing engine were collected for each search term. The Rothwell classification system of questions by topic (Fact, Value, Policy) and websites by category was used (Commercial, Academic, Medical Practice, Single Surgeon Personal, Government, Social Media). Website quality was assessed using the Journal of the American Medical Association (JAMA) benchmark criteria (Likert-style rating 0-4). Pearson's Chi-squared and Student's t-tests were performed for statistical analysis as appropriate (significance, p < 0.05).

Results

The 10 search terms generated 454 questions and referenced 408 websites. Of the 454 questions generated, the most common question categories were fact (70.8%), value (19.2%), and policy (10%). The most common website type was social media (37.4%). The most common question types were technical details (30.4%), specific activity (20.6%), and cost (14.1%). Only 1.6% of questions related to risks and complications. Generally, website quality was poor with 64.1% having a JAMA score of 0 or 1. Websites that were categorised as 'Government' had the highest overall JAMA scores: 71.4% had a score of 4.

Conclusion

Based on Google search engine's results, the most commonly asked questions about osteointegration related to technical details, specific activities and cost; only 1.6% related to risks and complications. Interestingly, social media websites represented the highest volume of search result referrals. Overall, the quality of websites was poor with the most factual information coming from governmental websites.

How to cite this article

Murphy EP, Sheridan GA, Page BJ, et al. Modern Internet Search Analytics and Osseointegration: What Are Patients Asking and Reading Online? Strategies Trauma Limb Reconstr 2023;18(3):163-168.

Bone density changes after five or more years of unilateral lower extremity osseointegration: Observational cohort study

Context

Rehabilitation following lower extremity amputation presents multiple challenges, many related to the traditional prosthesis (TP) socket. Without skeletal loading, bone density also rapidly decreases. Transcutaneous osseointegration for amputees (TOFA) surgically implants a metal prosthesis attachment directly into the residual bone, facilitating direct skeletal loading. Quality of life and mobility are consistently reported to be significantly superior with TOFA than TP.

Objective

To investigate how femoral neck bone mineral density (BMD, g/cm²) changes for unilateral transfemoral and transtibial amputees at least five years following single-stage press-fit osseointegration.

Methods

Registry review was performed of five transfemoral and four transtibial unilateral amputees who had dual x-ray absorptiometry (DXA) performed preoperatively and after at least five years. The average BMD was compared using Student's t-test (significance p < .05). First, all nine Amputated versus Intact limbs. Second, the five patients with local disuse osteoporosis (ipsilateral femoral neck T-score < -2.5) versus the four whose T-score was greater than -2.5.

Results

The average Amputated Limb BMD was significantly less than the Intact Limb, both Before Osseointegration (0.658 ± 0.150 vs 0.929 ± 0.089, p < .001) and After Osseointegration (0.720 ± 0.096 vs 0.853 ± 0.116, p = .018). The Intact Limb BMD decreased significantly during the study period (0.929 ± 0.089 to 0.853 ± 0.116, p = .020), while the Amputated Limb BMD increased a not statistically significant amount (0.658 ± 0.150 to 0.720 ± 0.096, p = .347). By coincidence, all transfemoral amputees had local disuse osteoporosis (BMD 0.545 ± 0.066), and all transtibial patients did not (BMD 0.800 ± 0.081, p = .003). The local disuse osteoporosis cohort eventually had a greater average BMD (not statistically significant) than the cohort without local disuse osteoporosis (0.739 ± 0.100 vs 0.697 ± 0.101, p = .556).

Conclusions

Single-stage press-fit TOFA may facilitate significant BMD improvement to unilateral lower extremity amputees with local disuse osteoporosis.