Detecting Changes in Comfort, Pain, and Mobility Over Clinical Milestones for Individuals With Lower Limb Loss

Background: Functional mobility, comfort and the absence of pain are key goals of prosthetic treatment. Outcome measures (OMs) evaluate the impact of treatment and normative and minimal detectable change (MDC) values are key to interpreting these scores and measuring treatment outcomes.

Objectives: This study seeks to 1) present practice-based normative values of four commonly used OMs at four prosthetic milestones and 2) explore the MDC of the measures over the treatment period.

Methodology: A chart review was conducted of OMs collected with individuals with lower limb loss between January 1, 2015, and December 31, 2023. This included data for individuals with unilateral transtibial (TT), transfemoral (TF) and rotationplasty (RP) amputations and bilateral transtibial amputation (BTT). OMs included the Socket Comfort Score (SCS), Pain Scale (PS), 2 Minute Walk Test (2MWT), and Prosthetic Limb Users Survey of Mobility (PLUS-M). Data were collected at four milestone time points: (1) Baseline and (2) Discharge from Rehabilitation for those in initial prosthetic rehabilitation, and (3) Initial Evaluation and (4) Definitive Delivery for those receiving a replacement socket. Normative values and MDC values were calculated.

Findings: Data from 30 individuals undergoing in-patient rehabilitation and 74 individuals receiving a replacement socket were included. Practice-based normative data were different for each level of amputation and milestone and had the following ranges: SCS: 5.7 - 9.1, PS: 0.8 - 3.7, 2MWT: 68.4 - 146.3 m and PLUS-M: 38.9 - 57.3. MDC values also varied based on time in treatment (Rehabilitation: SCS = 2.5, PS = 1.6, 2MWT = 32.6, PLUS-M = 8.8; Replacement Socket: SCS = 3.1, PS = 2.6, 2MWT = 38.9, PLUS-M = 4.0). All measures had a statistically significant change over the intervention, however, no average scores changed by greater than the MDC.

Conclusions: The normative data and MDC scores demonstrate the PS & PLUS-M are useful measures of pain and mobility at all points within treatment. The 2MWT is indicated for individuals in rehabilitation, while the SCS is indicated for those receiving a replacement socket, as both effectively measure treatment goals that are particularly important for each phase of rehabilitation. This provides clinicians with practice-based evidence that enables them to interpret OM scores, a critical part of the decision-making process along the treatment journey.