Knee scooter related injuries and satisfaction in patients following foot and ankle surgery.

BACKGROUND: Knee scooters have become popular amongst foot and ankle surgeons for patients who are required to be non-weight bearing. Information is limited regarding falls and injuries sustained while using a knee scooter and potential contraindications to their use are ill-defined. No study has assessed patient reported injuries and satisfaction. This study aims to evaluates the patient's perspective with regards to the use of a knee scooter. As a secondary aim we assessed for risk factors associated with knee scooter related injuries to try make recommendations for the safe use of a knee scooter. METHODS: Patients who used a knee scooter during 2018-2020 were emailed a questionnaire assessing (1) demographic data, (2) medical history, (3) falls and injuries sustained, including the management of these injuries, and (4) patient satisfaction. This study is a descriptive, cross-sectional survey analysis. RESULTS: 101/196 (51,5%) responses were received, which included 32 males and 69 females. The cohort had a mean age of 56.4 years, and BMI of 28.5. Mean time spent using the scooter was 6.7 weeks. Twenty-five respondents had fallen off the scooter, with 5 reporting injuries. One patient required medical attention for a shoulder injury. Cause of falls included hitting an obstacle, making a sharp turn, moving too fast, and moving downhill. There was no correlation between falls and patient comorbidities. Ninety-six percent of respondents reported a high satisfaction and preferred the scooter to crutches. CONCLUSION: The knee scooter is a safe, and well-tolerated, mobility aid for patients requiring non-weight bearing during their recovery, with a high satisfaction rate. Educating patients on correct use and common causes for falling is important as a preventative measure. LEVEL OF EVIDENCE: IV, retrospective case series.

Analysis of Wheeled Knee Walker Use following Foot and Ankle Surgery or Injury.

To determine patient satisfaction and safety with wheeled knee walkers, we performed a retrospective, observational, and descriptive study. Inclusion criteria were age ≥18 years, unilateral foot or ankle surgery, non-weightbearing status, and being given the option of using the knee walker. Surveys were sent to eligible patients, and chart review included only those patients who returned surveys. Primary endpoints were occurrence and frequency of falls. Secondary endpoints were patient demographics, comorbidities, knee walker characteristics, duration of use, and patient satisfaction. We also attempted to identify associations between falls and patient characteristics. Eighty participants, 51 females and 29 males, responded adequately to the survey. The mean age of respondents was 55.6 ± 13.0 years and their mean body mass index (BMI) was 30.2 ± 5.9 kg/m2. Most used a steerable, 4-wheeled knee walker. Almost half (46%) had no prior experience with any type of walking aids, and none had experience using a knee walker. Two thirds (66%) did not receive any instruction on usage of the knee walker. Thirty-four (43%) of the 80 respondents fell while using the knee walker; nearly two thirds (62%) of those who fell reported multiple falls. Sixteen (55%) of 29 males compared to 18 (36%) of 50 females reported falling (p = .097). There was no statistical association between falls and age, BMI, or number of comorbidities. Most respondents (91%) who fell still reported satisfaction with the knee walker. Nearly half (43%) experienced falling, and nearly two thirds (64%) of those who fell had multiple falls.

An Able-Bodied Study for Potential Usage of a Knee Scooter as a Constraint-Induced Movement Therapy (CIMT) Gait Training Device.

Post-stroke gait is characterized by slow and asymmetrical hemiparetic gait. This is attributed to the paretic lower limb which has limited plantar propulsion. The most effective method to restore paretic limb function is constraint-induced movement therapy (CIMT), which promotes the usage of the paretic limb by restricting the movement of the unafflicted limb. However, due to the necessity of both lower limbs to perform gait, CIMT methods could not be directly applied for gait rehabilitation. In this study, we explore the feasibility of utilizing a knee scooter as a means to facilitate CIMT gait training. We hypothesize that if lower limb kinematics and muscle activation patterns during gait with a knee scooter match that of natural gait, the knee scooter could be utilized for CIMT gait training. We measured the lower-limb joint angles, plantar force, EMG patterns, stride length, and step times of 13 healthy subjects during gait with a knee scooter and natural gait. The results suggest that the gait patterns while using the knee scooter closely resemble those of natural gait.

Orthopaedic knee scooter-related injury: prevalence and patient safety perception in a prospective cohort with exploratory risk factor analysis.

BACKGROUND: There is a paucity of research investigating the harms associated with orthopaedic knee scooter (OKS) use and patient safety perceptions. This prospective study aimed to define the prevalence of OKS-related injuries, describe the patient perceptions of OKS safety, and identify potential risk factors. METHODS: This study was conducted at a single foot and ankle fellowship-trained surgeon's community-based clinic from 6/2020 to 4/2021 and enrolled 134 patients. Our primary outcome was an OKS-related event (injury or fall) and informed an a priori power analysis. Point estimate of association magnitude was calculated as an odds ratio (OR) for statistically and clinically significant associations. RESULTS: There were 118 (88%) patients eligible for analysis; fourteen enrolled patients did not use OKS, and two withdrew. The prevalence of patient falls was 37% (44/118), and the prevalence of patient injury was 15% (18/118). Four percent of patients would not recommend OKS and 8% would not use an OKS again. Sedentary lifestyle increased risk (OR = 4.67, 1.52-14.35 95 CI) for OKS-related injury. CONCLUSIONS: Despite a high prevalence of patient falls (37%), there is a low prevalence of injury (15%) and a favorable perception of OKS safety. Sedentary lifestyles may be a risk factor for OKS-related injury and should be considered in the development of a risk model.

EMG Activity With Use of a Hands-Free Single Crutch vs a Knee Scooter.

BACKGROUND: Foot and ankle injuries frequently require a period of nonweightbearing, resulting in muscle atrophy. Our previous study compared a hands-free single crutch (HFSC) to standard axillary crutches and found increased muscle recruitment and intensity while using the HFSC. Knee scooters are another commonly prescribed nonweightbearing device. The purpose of this study is to examine the electromyographic (EMG) differences between an HFSC and knee scooter, in conjunction with device preference and perceived exertion. METHODS: A randomized crossover study was performed using 30 noninjured young adults. Wireless surface EMG electrodes were placed on the belly of the rectus femoris (RF), vastus lateralis (VL), lateral gastrocnemius (LG), and gluteus maximus (GM). Participants then ambulated along a 20-m walking area while 15 seconds of the gait cycle was recorded across 3 conditions: walking with a knee scooter, an HFSC, and with no assistive device. Mean muscle activity and peak EMG activity were recorded for each ambulatory modality. Immediately following testing, patient exertion and device preference was recorded. RESULTS: The RF, LG, and GM showed increased peak EMG activity percentage, and the LG showed increased mean muscle activity while using the HFSC compared with the knee scooter. When comparing the knee scooter and HFSC to walking, both showed increased muscle activity in the RF, VL, and LG but no difference in the GM. There was no statistical difference in participant preference, whereas the HFSC had a statistically significant higher perceived exertion than the knee scooter (P < .001). CONCLUSION: In this group of young, healthy noninjured volunteers, the HFSC demonstrated increased peak EMG activity in most muscle groups tested compared with the knee scooter. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Knee Scooter-Related Injuries: A Survey of Foot and Ankle Orthopedic Surgeons.

BACKGROUND: Knee scooters ("scooters") are a commonly used device to facilitate postoperative adherence to weightbearing restrictions. Although high rates of falls have been reported, little is known about injuries related to scooter use. METHODS: We analyzed survey responses from 316 of 2046 members (15%) of the American Orthopaedic Foot & Ankle Society in May-June 2019 describing (1) frequency of scooter recommendation; (2) indications for which they recommended scooters; (3) characteristics of patients for whom they recommended scooters; (4) prevalence, anatomic locations, mechanisms, and sequelae of scooter-related injuries; and (5) characteristics of patients with scooter-related injuries. Descriptive statistics and χ2 goodness-of-fit tests were performed (alpha = .05). RESULTS: Mean frequency with which respondents recommended scooters in particular was 69%. Respondents most often recommended scooters after hindfoot arthrodesis (97% [305/316]), ankle arthrodesis (96% [302/316]), and for total nonweightbearing (64% [202/316]) and to patients who were overweight (vs obese) or aged 45-75 years. Mean prevalence of scooter-related injuries was 2.5%. The most common injury mechanism was making a sharp turn (reported by 62% [103/166]). Thirty-four percent (56/166) of respondents with injured patients said patients underwent surgery to treat scooter-related injuries. Patients with scooter-related injuries were more often women, >44 years old, obese, and sedentary. CONCLUSION: Scooters were commonly recommended postoperatively, most often for total nonweightbearing after hindfoot or ankle arthrodesis, and most often in overweight adults or those aged 45-75 years. Mean reported prevalence of scooter-related injuries was 2.5%. Female sex, older age, obesity, and sedentary lifestyle were associated with scooter-related injury. LEVEL OF EVIDENCE: Level IV, retrospective case series.