Epidemiology of Limb Amputations and Prosthetic Use During COVID-19 Pandemic in the Netherlands.

OBJECTIVE: To evaluate the trends in the incidence of major limb amputations and the prevalence of Dutch prosthetic users at the national level in The Netherlands between 2012 and 2021 (during the COVID-19 pandemic). Local hospitals in The Netherlands reported a doubling of major lower limb amputations during COVID-19, information about a change in the incidence of major upper limb amputations was not reported. We could not confirm this remarkable increase in major lower limb amputations in our institution, nor did we observe a change in the incidence of major upper limb amputations. We hypothesize that the COVID-19 pandemic had no effect on the number of major limb amputations. DESIGN: Observational retrospective study analyzing national open-access databases of health insurance claims. SETTING: The Dutch national opensource database www.opendisdata.nl was used to retrieve the incidence of limb amputations in the period 2012-2021, stratified by the level of amputation and the cause of amputation. The results were verified using the www.gipdatabank.nl databank. This period included 4 intervals of nationwide COVID-19 lockdowns. PARTICIPANTS: 60,848 patients who underwent limb amputations at the upper or lower extremity in the Netherlands from 2012 to 2021 (N=60,848) were included in this study. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Upper- and lower-limb amputation and prosthetic use. RESULTS: Data were retrieved for a total of 60,848 patients in the Netherlands, who underwent 68,180 amputations of the upper and lower extremities at any level from 2012 to 2021, including 22,095 major amputations of the lower extremities. The ongoing trend of stable numbers of major lower-limb amputations from 2012 to 2019 continued in 2020 and 2021. The verification of these data at the level of prosthetic users confirmed that the annual trends were unchanged. CONCLUSION: The reported increased numbers of major lower-limb amputations during the COVID-19 pandemic in the Netherlands could not be confirmed using nationwide epidemiologic data.

Evaluating the Effectiveness of Transtibial Prosthetic Socket Shape Design using Artificial Intelligence: A Clinical Comparison with Traditional Plaster Cast Socket Designs.

OBJECTIVE: This study investigates the feasibility of creating an AI algorithm to enhance prosthetic socket shapes for transtibial prostheses, aiming for a less operator-dependent, standardized approach. DESIGN: The study comprised two phases: first, developing an AI algorithm in a cross-sectional study to predict prosthetic socket shapes. Second, testing the AI-predicted Digitally Measured and Standardized Designed (DMSD-)prosthetic socket against a Manually Measured and Designed (MMD-)prosthetic socket in a two-week within-subject cross-sectional study. SETTING: The study was done at the rehabilitation department of the Radboud University Medical Center in Nijmegen, the Netherlands. PARTICIPANTS: The AI algorithm was developed using retrospective data from 116 patients from a Dutch orthopedic company: OIM Orthopedie, and tested on ten randomly selected participants from Papenburg Orthopedie. INTERVENTIONS: Utilization of an AI algorithm to enhance the shape of a transtibial prosthetic socket. MAIN OUTCOME MEASURES: The algorithm was optimized to minimize the error in the test set. Participants' Socket Comfort Score (SCS) and fitting ratings from an independent physiotherapist and prosthetist were collected. RESULTS: Predicted prosthetic shapes deviated by 2.51 mm from the actual designs. 8/10 DMSD and all 10 MMD-prosthetic sockets were satisfactory for home testing. Participants rated DMSD prosthetic sockets at 7.1 ± 2.2 (n=8) and MMD prosthetic sockets at 6.6 ± 1.2 (n=10) on average. CONCLUSION: The study demonstrates promising results for using an AI algorithm in prosthetic socket design, but long-term effectiveness and refinement for improved comfort and fit in more deviant cases are necessary.

The influence of prosthetic suspension on gait and cortical modulations is persons with a transfemoral amputation: socket-suspended versus bone-anchored prosthesis.

BACKGROUND: Persons with a transfemoral amputation (TFA) often experience difficulties in daily-life ambulation, including an asymmetrical and less stable gait pattern and a greater cognitive demand of walking. However, it remains unclear whether this is effected by the prosthetic suspension, as eliminating the non-rigid prosthetic connection may influence stability and cortical activity during walking. Spatiotemporal and stability-related gait parameters, as well as cortical activity during walking, were evaluated between highly active individuals (MFC-level K3-4) with a TFA and able-bodied (AB) persons, and between persons with a bone-anchored prosthesis (BAP) and those with a socket-suspended prosthesis (SSP). METHODS: 18 AB persons and 20 persons with a unilateral TFA (10 BAP-users, 10 SSP-users) walked on a treadmill at their preferred speed. Spatiotemporal and margin of stability parameters were extracted from three-dimensional movement recordings. In addition, 126-channel electroencephalogram (EEG) was recorded. Brain-related activity from several cortical areas was isolated using independent component analysis. Source-level data were divided into gait cycles and subjected to time-frequency analysis to determine gait-cycle dependent modulations of cortical activity. RESULTS: Persons with TFA walked with smaller and wider steps and with greater variability in mediolateral foot placement than AB subjects; no significant differences were found between BAP- and SSP-users. The EEG analysis yielded four cortical clusters in frontal, central (both hemispheres), and parietal areas. No statistically significant between-group differences were found in the mean power over the entire gait cycle. The event-related spectral perturbation maps revealed differences in power modulations (theta, alpha, and beta bands) between TFA and AB groups, and between BAP- and SSP-users, with largest differences observed around heel strike of either leg. CONCLUSIONS: The anticipated differences in gait parameters in persons with TFA were confirmed, however no significant effect of the fixed suspension of a BAP was found. The preliminary EEG findings may indicate more active monitoring and control of stability in persons with TFA, which appeared to be timed differently in SSP than in BAP-users. Future studies may focus on walking tasks that challenge stability to further investigate differences related to prosthetic suspension.

Have Surgery and Implant Modifications Been Associated With Reduction in Soft Tissue Complications in Transfemoral Bone-anchored Prostheses?

BACKGROUND: The most frequently occurring adverse events in individuals with a transfemoral amputation treated with a bone-anchored prosthesis are soft tissue infections and stoma-related complications. These soft tissue complications are believed to be influenced by surgical technique and implant design, but little is known about the effect of changes to treatment on these events. QUESTIONS/PURPOSES: (1) What is the result of surgical technique and implant modifications on the incidence of soft tissue infections and stoma-related complications in transfemoral bone-anchored prosthesis users, depending on whether they had a conventional stoma and a cobalt-chrome-molybdenum (CoCrMo) osseointegration implant (treatment period 2009 to 2013) or a shallower stoma and titanium osseointegration implant (2015 to 2018)? (2) What is the incidence of serious complications, such as bone or implant infection, aseptic loosening, intramedullary stem breakage, and periprosthetic fracture? METHODS: Between 2009 and 2013, we performed osseointegration implant surgery using a conventional surgical technique and a CoCrMo implant in 42 individuals who had a lower extremity amputation experiencing socket-related problems that resulted in limited prosthesis use. We considered all individuals treated with two-stage surgery with a standard press-fit transfemoral osseointegration implant as potentially eligible for inclusion. Based on this, 100% (42) were eligible, and 5% (two of 42) were excluded because they did not provide informed consent, leaving 95% (40 of 42) for analysis. Between 2015 and 2018, we treated 79 individuals with similar indications with osseointegration implant surgery, now also treating individuals with dysvascular amputations. We used an adapted surgical technique resulting in a shallower stoma combined with a titanium implant. Using the same eligibility criteria as for the first group, 51% (40 of 79) were eligible; 49% (39 of 79) were excluded because they were treated with transtibial amputation, a patient-specific implant, or single-stage surgery and 1% (one of 79) were lost before the 2-year follow-up interval, leaving 49% (39 of 79) for analysis. The period of 2013 to 2015 was a transitional period and was excluded from analysis in this study to keep groups reasonably comparable and to compare a historical approach with the present approach. Hence, we presented a comparative study of two study groups (defined by surgical technique and implant design) with standardized 2-year follow-up. The risk factors for adverse events were similar between groups, although individuals treated with the shallow stoma surgical technique and titanium implant potentially possessed an increased risk because of the inclusion of individuals with dysvascular amputation and the discontinuation of prolonged postoperative antibiotic prophylaxis. Outcomes studied were soft tissue infections and stoma-related complications (hypergranulation or keloid formation as well as stoma redundant tissue) and bone or implant infection, aseptic loosening, implant stem breakage, periprosthetic fracture, and death. RESULTS: Patients treated with the shallow stoma surgical technique and titanium implant experienced fewer soft tissue infections (13 versus 76 events, absolute risk 0.17 [95% CI 0.09 to 0.30] versus 0.93 [95% CI 0.60 to 1.45]; p < 0.01), which were treated with less invasive measures, and fewer stoma redundant tissue events (0 versus five events, absolute risk 0 versus 0.06 [95% CI 0.03 to 0.14]) than patients treated with the conventional stoma surgical technique and CoCrMo implant. This was contrasted by an increased incidence of surgical site infections occurring between surgical stages 1 and 2, when no stoma was yet created, after the implementation of treatment changes (conventional surgery and CoCrMo implant versus shallow stoma surgery and titanium implant: one versus 11 events, absolute risk 0.01 [95% CI 0.00 to 0.08] versus 0.14 [95% CI 0.08 to 0.25]; p = 0.02). Patients treated with the shallow stoma surgical technique and titanium implant did not experience serious complications, although bone infections occurred (six events in 8% [three of 40] of patients) in the conventional surgery and CoCrMo implant group, all of which were successfully treated with implant retention. CONCLUSION: Adaptations to surgical technique and newer implant designs, as well as learning curve and experience, have resulted in a reduced incidence and severity of soft tissue infections and stoma redundant tissue, contrasted by an increase in surgical site infections before stoma creation. Serious complications such as deep implant infection were infrequent in this 2-year follow-up period. We believe the benefits of these treatment modifications outweigh the disadvantages and currently advise surgeons to create a shallower stoma with a stable soft tissue envelope, combined with a titanium implant. LEVEL OF EVIDENCE: Level III, therapeutic study.

Testing and evaluation of lower limb prosthesis prototypes in people with a transfemoral amputation: a scoping review on research protocols.

BACKGROUND: When developing new lower limb prostheses, prototypes are tested to obtain insights into the performance. However, large variations between research protocols may complicate establishing the potential added value of newly developed prototypes over other prostheses. OBJECTIVE: This review aims at identifying participant characteristics, research protocols, reference values, aims, and corresponding outcome measures used during prosthesis prototype testing on people with a transfemoral amputation. METHODS: A systematic search was done on PubMed and Scopus from 2000 to December 2020. Articles were included if testing was done on adults with transfemoral or knee disarticulation amputation; testing involved walking with a non-commercially available prototype leg prosthesis consisting of at least a knee component; and included evaluations of the participants' functioning with the prosthesis prototype. RESULTS: From the initial search of 2027 articles, 48 articles were included in this review. 20 studies were single-subject studies and 4 studies included a cohort of 10 or more persons with a transfemoral amputation. Only 5 articles reported all the pre-defined participant characteristics that were deemed relevant. The familiarization time with the prosthesis prototype prior to testing ranged from 5 to 10 min to 3 months; in 25% of the articles did not mention the extent of the familiarization period. Mobility was most often mentioned as the development or testing aim. A total of 270 outcome measures were identified, kinetic/kinematic gait parameters were most often reported. The majority of outcome measures corresponded to the mobility aim. For 48% of the stated development aims and 4% of the testing aims, no corresponding outcome measure could be assigned. Results indicated large inconsistencies in research protocols and outcome measures used to validate pre-determined aims. CONCLUSIONS: The large variation in prosthesis prototype testing and reporting calls for the development of a core set of reported participant characteristics, testing protocols, and specific and well-founded outcome measures, tailored to the various aims and development phases. The use of such a core set can give greater insights into progress of developments and determine which developments have additional benefits over the state-of-the-art. This review may contribute as initial input towards the development of such a core set.

What Are the Risk Factors for Mechanical Failure and Loosening of a Transfemoral Osseointegrated Implant System in Patients with a Lower-limb Amputation?

BACKGROUND: Septic loosening and stem breakage due to metal fatigue is a rare but well-known cause of orthopaedic implant failure. This may also affect the components of the osseointegrated implant system for individuals with transfemoral amputation who subsequently undergo revision. Identifying risk factors is important to minimize the frequency of revision surgery after implant breakage. QUESTIONS/PURPOSES: (1) What proportion of patients who received an osseointegrated implant after transfemoral amputation underwent revision surgery, and what were the causes of those revisions? (2) What factors were associated with revision surgery when stratified by the location of the mechanical failure and (septic) loosening (intramedullary stem versus dual cone adapter)? METHODS: Between May 2009 and July 2015, we treated 72 patients with an osseointegrated implant. Inclusion criteria were a minimum follow-up of 5-years and a standard press-fit cobalt-chromium-molybdenum (CoCrMb) transfemoral osseointegrated implant. Based on that, 83% (60 of 72) of patients were eligible; a further 3% (2 of 60) were excluded because of no received informed consent (n = 1) and loss to follow-up (n = 1). Eventually, we included 81% (58 of 72) of patients for analysis in this retrospective, comparative study. We compared patient characteristics (gender, age, and BMI), implant details (diameter of the intramedullary stem, length of the dual cone, and implant survival time), and event characteristics (infectious complications and distal bone resorption). The data were retrieved from our electronic patient file and from our cloud-based database and analyzed by individuals not involved in patient care. Failures were categorized as: (1) mechanical failures, defined as breakage of the intramedullary stem or dual-cone adapter, or (2) (septic) loosening of the osseointegrated implant. RESULTS: Thirty-four percent (20 of 58) of patients had revision surgery. In 12% (7 of 58) of patients, the reason for revision was due to intramedullary stem failures (six breakages, one septic loosening), and in 22% (13 of 58) of patients it was due to dual-cone adaptor failure (10 weak-point breakages and four distal taper breakages; one patient broke both the weak-point and the dual-cone adapter). Smaller median stem diameter (failure: 15 mm [interquartile range 1.3], nonfailure: 17 mm [IQR 2.0], difference of medians 2 mm; p < 0.01) and higher median number of infectious events (failure: 6 [IQR 11], nonfailure: 1 [IQR 3.0], difference of medians -5; p < 0.01) were associated with revision intramedullary stem surgery. No risk factors could be identified for broken dual-cone adapters. CONCLUSION: Possible risk factors for system failure of this osteointegration implant include small stem diameter and high number of infectious events. We did not find factors associated with dual-cone adapter weak-point failure and distal taper failure, most likely because of the small sample size. When treating a person with a lower-limb amputation with a CoCrMb osseointegrated implant, we recommend avoiding a small stem diameter. Further research with longer follow-up is needed to study the success of revised patients. LEVEL OF EVIDENCE: Level III, therapeutic study.

Identifying unmet needs and limitations in physical health in survivors of Head and Neck Cancer.

OBJECTIVE: To gain insight into the level of unmet needs and limitations in physical health experienced by survivors of head and neck cancer, and to evaluate whether unmet needs in physical health and limitations in physical performance are associated. MATERIALS AND METHODS: In this cross-sectional study, unmet needs were measured with Supportive Care Needs Surveys (SCNS-SF34, SCNS-HNC). Limitations in physical health were measured for maximal mouth opening, neck and shoulder function, hand grip strength and lower body strength, level of mobility and walking ability. RESULTS: The SCNSs showed that 48% had a cancer generic unmet need and 46% had at least one HNC-specific unmet need. In total, 76% of sHNC had a cancer generic limitation in physical health and that 58% had an HNC-specific limitation in the mobility of neck and shoulders or maximum mouth opening. The domain of physical and daily living needs showed a weak association with lateral flexion of the neck to the left (R = -0.319; p = 0.024). CONCLUSION: Survivors of HNC might benefit from the use of both SCNSs and physical performance measurements during usual care follow-up for early and optimal identification of unmet needs and limitations in physical health.

Functional performance and safety of bone-anchored prostheses in persons with a transfemoral or transtibial amputation: a prospective one-year follow-up cohort study.

OBJECTIVES:: (1) To compare level of function, activity, health-related quality of life (HRQoL) and satisfaction in persons with a lower extremity amputation before surgery and 6- and 12-months after implantation of an osseointegration implant and (2) to report adverse events. DESIGN:: Prospective cohort study. SETTING:: University medical centre. SUBJECTS:: A total of 40 consecutive persons (median age: 56 years) who received a transfemoral (31) or transtibial (9) osseointegration implant, between April 2014 and March 2016. INTERVENTION:: Osseointegration implant surgery followed by a predefined rehabilitation programme. MAIN MEASURES:: Hip abductor strength, prosthetic use, back pain frequency, postoperative pain, mobility level (Timed-Up and Go (TUG) and wheelchair-boundedness), walking ability (6 minute walking test (6MWT) and walking distance in daily life), HRQoL, satisfaction regarding the prosthesis, and adverse events. RESULTS:: Strength, prosthetic use, walking distance, HRQoL, and satisfaction level increased significantly at 6- and 12-month follow-up compared to baseline ( P ⩽ 0.002). The TUG showed no change at 6-month follow-up ( P = 0.420) but improved significantly at 12-month follow-up compared to baseline ( P = 0.005). Wheelchair-boundedness decreased from 12/40 participants at baseline to 0 at follow-ups. The 6MWT ( P ⩾ 0.038) and back pain ( P ⩾ 0.437) did not change over time. Stump pain was present in 28/39 and 22/40 of the participants at 6-and 12-month follow-up, respectively. The major adverse events were managed successfully and included three dual-cone breakages and four bone fractures. An uneventful course was completed by 19/31 transfemoral and 4/9 transtibial bone-anchored prostheses users. CONCLUSION:: Bone-anchored prostheses lead to improved performance and appear to be safe, so they might be considered for persons with socket-related problems.

Long-term outcomes following lower extremity press-fit bone-anchored prosthesis surgery: a 5-year longitudinal study protocol.

BACKGROUND: Patients with lower extremity amputation frequently suffer from socket-related problems. This seriously limits prosthesis use, level of activity and health-related quality of life (HRQoL). An additional problem in patients with lower extremity amputation are asymmetries in gait kinematics possibly accounting for back pain. Bone-anchored prostheses (BAPs) are a possible solution for socket-related problems. Knowledge concerning the level of function, activity and HRQoL after surgery is limited. The aims of this ongoing study are to: a) describe changes in the level of function, activity, HRQoL and satisfaction over time compared to baseline before surgery; b) examine potential predictors for changes in kinematics, prosthetic use, walking ability, HRQoL, prosthesis comfort over time and level of stump pain at follow-up; c) examine potential mechanisms for change of back pain over time by identifying determinants, moderators and mediators. METHODS/DESIGN: A prospective 5-year longitudinal study with multiple follow-ups. All adults, between May 2014 and May 2018, with lower extremity amputation receiving a press-fit BAP are enrolled consecutively. Patients with socket-related problems and trauma, tumour resection or stable vascular disease as cause of primary amputation will be included. Exclusion criteria are severe cognitive or psychiatric disorders. Follow-ups are planned at six-months, one-, two- and five-years after BAP surgery. The main study outcomes follow, in part, the ICF classification: a) level of function defined as kinematics in coronal plane, hip abductor strength, prosthetic use, back pain and stump pain; b) level of activity defined as mobility level and walking ability; c) HRQoL; d) satisfaction defined as prosthesis comfort and global perceived effect. Changes over time for the continuous outcomes and the dichotomized outcome (back pain) will be analysed using generalised estimating equations (GEE). Multivariate GEE will be used to identify potential predictors for change of coronal plane kinematics, prosthetic use, walking ability, HRQoL, prosthesis comfort and for the level of post-operative stump pain. Finally, potential mechanisms for change in back pain frequency will be explored using coronal plane kinematics as a potential determinant, stump pain as moderator and hip abductor strength as mediator. DISCUSSION: This study may identify predictors for clinically relevant outcome measures. TRIAL REGISTRATION: NTR5776 . Registered 11 March 2016, retrospectively registered.

Lumbopelvic movement coordination during walking improves with transfemoral bone anchored limbs: Implications for low back pain.

BACKGROUND: Low back pain (LBP) is more prevalent in patients with transfemoral amputation using socket prostheses than able-bodied individuals, in part due to altered spinal loading caused by aberrant lumbopelvic movement patterns. Early evidence surrounding bone-anchored limb functional outcomes is promising, yet it remains unknown if this novel prosthesis influences LBP or movement patterns known to increase its risk. RESEARCH QUESTION: How are self-reported measures of LBP and lumbopelvic movement coordination patterns altered when using a unilateral transfemoral bone-anchored limb compared to a socket prosthesis? METHODS: Fourteen patients with unilateral transfemoral amputation scheduled to undergo intramedullary hardware implantation for bone-anchored limbs due to failed socket use were enrolled in this longitudinal observational cohort study (7 F/7 M, Age: 50.2±12.0 years). The modified Oswestry Disability Index (mODI) (self-reported questionnaire) and whole-body motion capture during overground walking were collected before (with socket prosthesis) and 12-months following bone-anchored limb implantation. Lumbopelvic total range of motion (ROM) and continuous relative phase (CRP) segment angles were calculated during 10 bilateral gait cycles. mODI, total ROM, CRP and CRP variabilities were compared between time points. RESULTS: mODI scores were significantly reduced 12-months after intramedullary hardware implantation for the bone-anchored limb (P = 0.013). Sagittal plane trunk and pelvis total ROM during gait were reduced after implantation (P = 0.001 and P < 0.001, respectively). CRP values were increased (more anti-phase) in the sagittal plane during single limb stance and reduced (more in-phase) in the transverse plane during pre-swing of the amputated limb gait cycle (P << 0.001 and P = 0.029, respectively). No differences in CRP values were found in the frontal plane. SIGNIFICANCE: Decreases in mODI scores and lumbopelvic ROM, paired with the changes in lumbopelvic coordination, indicate that bone-anchored limbs may reduce LBP symptoms and reduce compensatory movement patterns for people with unilateral transfemoral amputation.

The significance of frontal plane static alignment in anticipating dynamic knee moment among transtibial prosthesis users: A cross-sectional study.

BACKGROUND: In the process of transtibial prosthetic fitting, alignment is the process of positioning the prosthetic foot relative to the residual limb. Changes in frontal plane alignment can impact knee moments during walking, which can either cause or, when aligned properly, prevent injuries. However, clinical evaluation of dynamic knee moments is challenging, limiting prosthetists' insights into dynamic joint loading. Typically, knee joint loading is assessed in static stance using the knee moment arm as a proxy for subsequent dynamic alignment. It remains uncertain if static alignment accurately represents actual dynamics during walking. RESEARCH QUESTION: Is the frontal knee moment arm in stance predictive for the knee moment arm and external knee adduction moment during gait in transtibial bone-anchored prosthesis users? METHODS: In this cross-sectional study, twenty-seven unilateral transtibial bone-anchored prosthesis users underwent data acquisition on the M-Gait instrumented treadmill. Static and dynamic measurements were conducted, and knee moment arm and external knee adduction moment were calculated. Pearson's correlation and linear regression analyses were performed to examine relationships between static and dynamic knee moment arms and external knee adduction moments. RESULTS: The static knee moment arm showed significant associations with dynamic knee moment arm at the ground reaction force peaks (First: r=0.60, r2=35%, p<0.001; Second: r=0.62, r2=38%, p=0.001) and knee adduction moment (First: r=0.42, r2=17%, p=0.030; Second: r=0.59, r2=35%, p=0.001). A 1 mm between-subject difference in static knee moment arm corresponded, on average, with a 0.9% difference in knee adduction moment at the first peak and a 1.5% difference at the second peak of the ground reaction force. SIGNIFICANCE: While static alignment is important to optimize adduction moments during stance it may only partly mitigate excessive moments during gait. The fair correlation and limited percentage of explained variance underscores the importance of dynamic alignment in optimizing the body's dynamic load during walking.

Patients' Preferences for Bone-Anchored Prostheses After Lower-Extremity Amputation: A 2-Center Discrete Choice Experiment in The Netherlands (PREFER-BAP-1).

BACKGROUND: The rising popularity and use of a bone-anchored prosthesis (BAP) involving an osseointegrated implant for patients with lower-limb amputations experiencing socket-related issues have led to increased interest in the measurement of clinical and functional outcomes. However, the value of BAP treatment characteristics from the patient perspective has not yet been investigated. This study aimed to determine the relative importance of specific BAP characteristics, and the effect of complications in quality-of-life (QoL) points and monetary utility decrement (loss [€]), using a 2-center discrete choice experiment (DCE) conducted in The Netherlands. METHODS: A DCE was developed that included the most salient characteristics of BAP treatment based on a review of the literature and qualitative and quantitative methods. The following characteristics were selected: QoL change, short- and long-term complications, osseointegrated implant survival, and out-of-pocket contributions (costs). Patients aged 18 to 99 years who were eligible for, or had already received, an osseointegrated implant were invited to participate, after informed consent, to elicit BAP treatment preferences. A Bayesian mixed logit model was used. RESULTS: Two hundred and forty-seven completed surveys were collected; 64% of the patients were male, 73% had undergone a transfemoral amputation, and 33% had >36 months of experience with a BAP. Patients considered long-term complications and QoL the most important characteristics. Long-term complications were 3.4 times more important than short-term complications. Opting out was undesirable, and patients valued better and beneficial levels (associated with better outcomes) of BAP characteristics positively. Implant removal was the level with the greatest loss among all complications, at 1.15 (95% credible interval [CI], 0.96 to 1.38) QoL points and €16,940 (95% CI, €14,780 to €19,040) loss. CONCLUSIONS: To our knowledge, this is the first study to use a DCE to elicit patients' preferences regarding BAP treatment, outcomes, and related complications; we found that patients strongly care about long-term complications. The results suggest that osseointegrated implant teams and policy-makers should consider these areas when proposing treatment protocols. Furthermore, policy and clinical guidelines for BAP treatment could be enhanced by our results with respect to patients' perspectives, management of patients' expectations, and associated losses in QoL points and monetary loss secondary to complications. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Oxygen consumption and gait dynamics in transfemoral bone-anchored prosthesis users compared to socket-prosthesis users: A cross-sectional study.

BACKGROUND: A transfemoral bone-anchored prosthesis (BAP) is an alternative for the conventional socket-suspended prosthesis (SSP) in persons suffering from socket-related problems. In these persons, it has been demonstrated to reduce oxygen consumption during walking, which could be related to centre of mass (CoM) and trunk dynamics. However, it remains uncertain whether the same comparative findings are found in SSP-users without any socket-related problems. RESEARCH QUESTION: Do oxygen consumption, CoM and trunk dynamics during walking differ between satisfied transfemoral SSP- and BAP-users and able-bodied individuals (AB); and are CoM and trunk dynamics and pistoning potential determinants of oxygen consumption? METHODS: Oxygen consumption was measured while participants walked on a treadmill at preferred speed, 30 % slower, and 30 % faster. At preferred speed, we also evaluated CoM deviation, root-mean-square values (RMS) of mediolateral (ML) CoM and trunk excursions, and pistoning. In the prosthetic users, we evaluated whether oxygen consumption, CoM and trunk dynamics, and pistoning were associated. RESULTS: We included BAP-users (n = 10), SSP-users (n = 10), and AB (n = 10). SSP-users demonstrated higher oxygen consumption, CoM and trunk RMS ML in comparison to AB during walking. BAP-users showed intermediate results between SSP-users and AB, yet not significantly different from either group. Greater CoM and trunk excursions were associated with higher oxygen consumption; in the SSP-users a greater degree of pistoning, in turn, was found to associate with larger trunk RMS ML. SIGNIFICANCE: Our results indicate that satisfied SSP-users have increased oxygen consumption compared to AB subjects and use compensatory movements during walking. An assessment of CoM and trunk dynamics, and pistoning during walking may be considered for evaluating whether an individual SSP-user could possibly benefit from a BAP, in addition to the currently used functional tests for evaluating eligibility. This might lead to a larger group of persons with a transfemoral SSP benefiting from this technology.

Effect of elective neck dissection versus sentinel lymph node biopsy on shoulder morbidity and health-related quality of life in patients with oral cavity cancer: A longitudinal comparative cohort study.

OBJECTIVE: To research the difference in shoulder morbidity and health-related quality of life between patients with cT1-2N0 oral cavity squamous cell carcinoma that undergo either elective neck dissection (END) or a sentinel lymph node biopsy (SLNB) based approach of the neck. MATERIALS AND METHODS: A longitudinal study with measurements before surgery, 6 weeks, 6 months, and 12 months after surgery. Shoulder morbidity were determined with measurements of active range of motion of the shoulder and patient-reported outcomes for shoulder morbidity (SDQ, SPADI) and health-related quality of life (HR-QoL) (EQ5D, EORTC-QLQ-HN35). Linear mixed model analyses were used to analyze differences over time between patients that had END, SLNB or SLNB followed by complementing neck dissection. RESULTS: We included 69 patients. Thirty-three patients were treated with END. Twenty-seven patients had SLNB without complementing neck dissection (SLNB), and nine were diagnosed lymph node positive followed by completion neck dissection (SLNB + ND). Ipsilateral shoulder abduction (P = .031) and forward flexion (P = .039) were significantly better for the SLNB group at 6 weeks post-intervention compared to the END and SLNB + ND group. No significant differences for shoulder morbidity, or health-related quality of life were found at 6 weeks, 6 months, and 12 months between the three groups. CONCLUSION: With oncologic equivalence for the END and SLNB as strategies for the cN0 neck already demonstrated, and the SLNB being more cost-effective, our demonstrated benefit in short-term shoulder function strengthens the choice for the SLNB as a preferred treatment strategy.

Reproducibility of measurements on physical performance in head and neck cancer survivors; measurements on maximum mouth opening, shoulder and neck function, upper and lower body strength, level of physical mobility, and walking ability.

BACKGROUND: Survivors of Head and Neck Cancer experience specific problems in functional performance. The aim of this study was to obtain the test-retest reliability of measurements on Maximal Mouth Opening (MMO), shoulder and neck function, lower and upper body strength, level of mobility and walking ability. MATERIALS AND METHODS: Test-retest study design. Measurements on MMO (intra- and extra orally), Active range of motion of shoulders and neck, 30 Seconds Chair Stand Test, Grip Strength, Timed Up and Go test, and Six Minute Walk test. RESULTS: In total 50 participants were included. The mean age was 68.6. ± 9.9 years and median time since end of treatment was 3.0 years (Q1-Q3: 1.0-5.25 years). We found good to excellent test-retest reliability on the core set of measurements (Intraclass Correlation Coefficient (ICC) 0.77 to 0.98). Measurement of MMO with cardboard card, forward flexion shoulder and Six Minute Walk test had a relatively small measurement error (Smallest Detectable Change (SDC) % 5.4% - 15.1%). Measurement of MMO with a caliper, shoulder abduction, shoulder external rotation, later flexion and rotation of the neck, grip strength, 30 Seconds Chair Stand Test, and Timed up and Go test had a relatively large measurement error (SDC% 19.8% - 44.7%). CONCLUSION: This core set of measurements on physical performance is found reliable and therefore able to differentiate in physical performance. The reported measurement errors should be taken into consideration when interpreting the results of repeated measurements. IMPLICATIONS FOR CANCER SURVIVORS: A core set of physical measurements can be used to measure physical performance in survivors of Head and Neck Cancer.

Reproducibility and discriminant validity of two clinically feasible measurement methods to obtain coronal plane gait kinematics in participants with a lower extremity amputation.

INTRODUCTION: Measuring coronal plane gait kinematics of the pelvis and trunk during rehabilitation of participants with a lower extremity amputation is important to detect asymmetries in gait which are hypothesised as associated with secondary complaints. The aim of this study was to test the reproducibility and discriminant validity of a three-dimensional (3-D; inertial measurement units) and a two-dimensional (2-D; video-based) system. METHODS: We tested the test-retest and inter-rater reproducibility of both systems and the 2-D system, respectively, in participants with a lower extremity amputation (group 1) and healthy subjects (group 2). The discriminant validity was determined with a within-group comparison for the 3-D system and with a between-group comparison for both systems. RESULTS: Both system showed to be test-retest reliable, both in group 1 (2-D system: ICC3.1agreement 0.52-0.83; 3-D system: ICC3.1agreement 0.81-0.95) and in group 2 (3-D system: ICC3.1agreement 0.33-0.92; 2-D system: ICC3.1agreement 0.54-0.95). The 2-D system was also inter-rater reliable (group 1: ICC2.1agreement 0.80-0.92; group 2: ICC2.1agreement 0.39-0.90). The within-group comparison of the 3-D system revealed a statistically significant asymmetry of 0.4°-0.5° in group 1 and no statistically significant asymmetry in group 2. The between-group comparison revealed that the maximum amplitude towards the residual limb (MARL) in the low back (3-D system) and the (residual) limb-trunk angle (2-D system) were significantly larger with a mean difference of 1.2° and 6.4°, respectively, than the maximum amplitude of healthy subjects. However, these average differences were smaller than the smallest detectable change (SDC) of group 1 for both the MARL (SDCagreement: 1.5°) and the residual limb-trunk angle (SDCagreement: 6.7°-7.6°). CONCLUSION: The 3-D and 2-D systems tested in this study were not sensitive enough to detect real differences within and between participants with a lower extremity amputation and healthy subjects although promising reproducibility parameters for some of the outcome measures.

Magnetic-resonance-imaging-based three-dimensional muscle reconstruction of hip abductor muscle volume in a person with a transfemoral bone-anchored prosthesis: A feasibility study.

BACKGROUND: Persons with transfemoral amputation typically have severe muscle atrophy of the residual limb. The effect of bone-anchored prosthesis use on existing muscle atrophy is unknown. A potentially feasible method to evaluate this is magnetic resonance imaging (MRI)-based three-dimensional (3D) muscle reconstruction. We aimed to (1) examine the feasibility of MRI-based 3D muscle reconstruction technique in a person with a cobalt-chrome-molybdenum transfemoral bone-anchored prosthesis; and (2) describe the change of hip abductor muscle volume over time. METHODS: In this single case, 1-year follow-up study we reconstructed the 3D hip abductor muscle volumes semiautomatically from MRI scans at baseline, 6- and 12-month follow-up. The number of adverse events, difficulties in data analysis, time investment and participants' burden determined the level of feasibility. RESULTS: We included a man (70 years) with a transfemoral amputation who received a bone-anchored prosthesis after 52 years of socket prosthesis use. No adverse events occurred. The accuracy of the 3D reconstruction was potentially reduced by severe adipose tissue interposition. Data analysis was time-intensive (115 h). Participants' burden was limited to 3-h time investment. Compared to baseline, the total hip abductor volume of both the residual limb (6 month: 5.5%; 12 month: 7.4%) and sound limb (6 month: 7.8%; 12 month: 5.5%) increased. CONCLUSION: The presented technique appears feasible to follow muscle volume changes over time in a person with a cobalt-chrome-molybdenum transfemoral bone-anchored prosthesis in an experimental setting. Future research should focus on analysis of muscle tissue composition and the feasibility in bone-anchored prostheses of other alloys.

[Osseointegration click-on prosthesis following leg amputation]. / Osseo-integratieklikprothese bij beenamputatie.

Since its introduction in 2009, more than 150 people in the Netherlands have received an osseointegration prosthesis following leg amputation. Serious complications such as septic or aseptic loosening and breakage of the implant are rare. In this article we highlight the results so far, the indications and contra-indications, our first experiences with patients who have undergone amputation due to vascular disease, and the future of osseointegration treatment in the Netherlands.

Complications of bone-anchored prostheses for individuals with an extremity amputation: A systematic review.

BACKGROUND: This study aimed to provide an overview of device-related complications occurring in individuals with an upper or lower extremity amputation treated with a screw, press-fit or other type of bone-anchored implant as well as interventions related to these complications. METHOD: A systematic literature search was conducted in the MEDLINE, Cochrane, EMBASE, CINAHL and Web of Science databases. The included studies reported on device-related complications and interventions occurring in individuals with bone-anchored prostheses. The outcomes evaluated were death, infection, bone/device breakage, implant loosening, soft tissue complications, systemic events, antibiotic and surgical treatment. Subgroup analyses were performed for the following groups: a) implant type (screw, press-fit and other types of implants) and b) level of amputation (transfemoral, transtibial and upper extremity amputation). RESULTS: Of 309 studies, 12 cohort studies were eligible for inclusion, all of which had methodological shortcomings and 12 studies were excluded due to complete overlap of patient data. Implant infection were rare in certain transfemoral implants (screw: 2-11%, press-fit: 0-3%, Compress: 0%) but common in transtibial implants (29%). The same was observed for implant loosening, in transfemoral (screw: 6%, press-fit: 0-3%, Compress: 0%), transtibial implants (29%) as well as for upper extremity implants (13-23%). Intramedullary device breakage were rare in transfemoral implants (screw: 0%, press-fit: 1%, Compress: unknown) but frequent in individuals with transradial implants (27%) and absent in transtibial implants. Soft tissue infections and complications were common and underreported in most articles. CONCLUSIONS: Major complications (e.g. implant infection, implant loosening and intramedullary device breakage) are rare in transfemoral bone-anchored prosthesis and seem to occur less frequently in individuals with press-fit implants. Minor complications, such as soft tissue infections and complications, are common but are substantially influenced by the learning curve, implant design and surgical technique. Data for patients treated with a transtibial, upper extremity or Compress implant are underreported, precluding definitive conclusions. There is a need for either an international database to report on or a standard core set of complications as well as the need to follow classification systems that result in unequivocal data.

Gait symmetry and hip strength in women with developmental dysplasia following hip arthroplasty compared to healthy subjects: A cross-sectional study.

INTRODUCTION: Untreated unilateral developmental dysplasia of the hip (DDH) results in asymmetry of gait and hip strength and may lead to early osteoarthritis, which is commonly treated with a total hip arthroplasty (THA). There is limited knowledge about the obtained symmetry of gait and hip strength after the THA. The objectives of this cross-sectional study were to: a) identify asymmetries between the operated and non-operated side in kinematics, kinetics and hip strength, b) analyze if increased walking speed changed the level of asymmetry in patients c) compare these results with those of healthy subjects. METHODS: Women (18-70 year) with unilateral DDH who had undergone unilateral THA were eligible for inclusion. Vicon gait analysis system was used to collect frontal and sagittal plane kinematic and kinetic parameters of the hip joint, pelvis and trunk during walking at comfortable walking speed and increased walking speed. Furthermore, hip abductor and extensor muscle strength was measured. RESULTS: Six patients and eight healthy subjects were included. In the patients, modest asymmetries in lower limb kinematics and kinetics were present during gait, but trunk lateral flexion asymmetry was evident. Patients' trunk lateral flexion also differed compared to healthy subjects. Walking speed did not significantly influence the level of asymmetry. The hip abduction strength asymmetry of 23% was not statistically significant, but the muscle strength of both sides were significantly weaker than those of healthy subjects. CONCLUSIONS: In patients with a DDH treated with an IBG THA modest asymmetries in gait kinematics and kinetics were present, with the exception of a substantial asymmetry of the trunk lateral flexion. Increased walking speed did not result in increased asymmetries in gait kinematics and kinetics. Hip muscle strength was symmetrical in patients, but significantly weaker than in healthy subjects. Trunk kinematics should be included as an outcome measure to assess the biomechanical benefits of the THA surgery after DDH.