This pilot observational study aims to examine the relationship between pain beliefs, pain intensity, and functional performance in individuals who have undergone cosmetic lower limb lengthening surgery using the Lengthening Over Nail (LON) technique.

Seventeen healthy male participants aged between 20 and 50 years who have undergone bilateral lower limb lengthening with the LON method will be included in the study. All evaluations will be performed during a face-to-face clinical visit at the fourth postoperative week.

Pain intensity will be assessed using the Visual Analog Scale (VAS). Pain beliefs will be evaluated using the Pain Beliefs Questionnaire. Functional performance will be measured with the 6-Minute Walk Test (6MWT).

The study aims to better understand how patients' beliefs about pain may influence their perceived pain level and physical performance after cosmetic limb lengthening surgery. Findings may contribute to improving postoperative rehabilitation planning and patient management.

This study is designed as a descriptive, cross-sectional pilot study. The objective is to investigate the relationship between pain beliefs, pain intensity, and functional performance in individuals who have undergone cosmetic bilateral lower limb lengthening surgery using the Lengthening Over Nail (LON) technique.

Background: Cosmetic limb lengthening procedures have increasingly been performed not only for limb length discrepancy but also for aesthetic purposes. Although the surgical technique has advanced over time, postoperative functional outcomes and psychological factors influencing recovery require further investigation. Pain beliefs, which may include both organic and psychological components, can influence pain perception, coping strategies, and physical performance during rehabilitation.

Participants: Individuals aged between 20 and 50 years who have undergone bilateral lower limb lengthening surgery with the LON technique and who have completed the early postoperative rehabilitation phase will be eligible. Participants with neurological, rheumatological, systemic diseases, major postoperative complications (e.g., infection, implant failure), or conditions limiting physical activity will be excluded.

Procedures: Participants will be invited for a face-to-face clinical evaluation at the fourth postoperative week. During this visit, the following assessments will be performed:

Demographic and clinical data collection (age, sex, body weight, external fixator distraction amount)

Pain intensity assessment using the Visual Analog Scale (VAS)

Pain beliefs assessment using the Pain Beliefs Questionnaire

Functional performance evaluation using the 6-Minute Walk Test (6MWT)

All measurements will be conducted under standardized conditions and supervised by a physiotherapist.

Outcome Measures:

The primary outcomes are pain intensity (VAS score), pain beliefs (Pain Beliefs Questionnaire scores), and functional performance (6MWT distance). The study aims to determine whether significant relationships exist between pain beliefs and functional performance, as well as between pain intensity and physical capacity.

Significance:

Understanding the interaction between psychological factors and functional outcomes after cosmetic limb lengthening surgery may contribute to improving postoperative rehabilitation strategies and individualized patient management

Inclusion Criteria:

• Age between 20 and 50 years
• Underwent bilateral lower extremity cosmetic lengthening surgery using the LON (Lengthening Over Nail) technique
• Completed postoperative rehabilitation process
• Attending routine clinical follow-up at postoperative week 4
• Able to understand and complete questionnaires
• Provided written informed consent

Exclusion Criteria:

• History of orthopedic surgery other than lower extremity lengthening
• Presence of neurological, rheumatologic, or systemic diseases affecting physical performance
• Postoperative complications such as infection, pseudoarthrosis, or implant failure
• Any condition preventing participation in physical assessment
• Incomplete clinical records

The study population consists of adults aged 20 to 50 years who underwent bilateral lower extremity cosmetic lengthening surgery using the LON (Lengthening Over Nail) technique and are attending routine postoperative follow-up at week 4 in a single tertiary care center.

Individual participant data (IPD) will not be shared. The study is a single-center academic research project conducted as part of a doctoral dissertation. Data contain sensitive health information and no data-sharing agreement or repository plan has been established.