Risk Factors and a Predictive Nomogram for Acute Moderate-to-severe Postoperative Pain After Achilles Tendon Surgery

Risk Factors and a Predictive Nomogram for Acute Moderate-to-severe Postoperative Pain Afte Achilles Tendon Surgery: A Retrospective Cohort Study

This is a single-center retrospective cohort study to identify independent risk factors and develop a predictive nomogram for moderate-to-severe pain within 24 hours after Achilles tendon surgery.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain
• Intervention / Treatment: Other: No Study-Specific Intervention

• Study Type: Observational
• Enrollment (Actual): 489

Contacts and Locations

Study Locations

• China
  • Beijing, China, 100191
    • Peking University Third Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adult patients (≥18 years) who underwent Achilles tendon surgery at Peking University Third Hospital between January 2020 and December 2024. Eligible patients were those with complete perioperative data and standardized 24-hour postoperative pain assessments, meeting all inclusion and exclusion criteria of the study.

Description

Inclusion Criteria:

1. Age ≥ 18 years; American Society of Anesthesiologists (ASA) physical status classification Ⅰ~Ⅲ;
2. Clinically diagnosed with Achilles tendon rupture, Achilles tendinopathy, insertional Achilles tendinitis, Haglund's deformity, or other Achilles tendon disorders;
3. Undergoing open or arthroscopic Achilles tendon surgery;
4. Conscious and able to cooperate in surgery and postoperative pain assessment;
5. Complete and accessible case data related to surgery, anesthesia, and postoperative pain assessment;
6. Completion of at least 24 hours of standardized pain monitoring and clinical follow-up after surgery

Exclusion Criteria:

1. Missing or incomplete key clinical data such as pain assessment, surgery and anesthesia;
2. Failure to complete 24-hour standardized pain monitoring after surgery; Perioperative unplanned secondary surgery or transfer to the intensive care unit (ICU);
3. Patients with mental illness, cognitive dysfunction, or language communication barrier; History of alcohol or drug addiction Pain due to other acute or chronic diseases;
4. Bilateral Achilles tendon surgery Concurrent surgery for other lower extremity injuries

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Moderate-to-Severe Acute Postoperative Pain	Defined as a pain score ≥ 4 on the Numeric Rating Scale (NRS) or the need for rescue analgesia within the first 24 hours after Achilles tendon surgery. The NRS is an 11-point scale ranging from 0 (no pain) to 10 (worst imaginable pain), where higher scores indicate greater pain severity (worse outcome).	Within 24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rescue Analgesia Requirement	Proportion of patients requiring rescue analgesic medications within 24 hours after surgery.	Within 24 hours after surgery
Incidence of Postoperative Nausea and Vomiting (PONV)	Proportion of patients experiencing nausea or vomiting requiring antiemetic treatment within 24 hours after surgery.	Within 24 hours after surgery
Postoperative Length of Hospital Stay	Number of days from surgery to hospital discharge.	From surgery to hospital discharge (up to 7 days)
Highest Postoperative Pain Score	The maximum pain score recorded within 24 hours after Achilles tendon surgery, measured using the Numeric Rating Scale (NRS). The NRS is an 11-point scale ranging from 0 (no pain) to 10 (worst imaginable pain), where higher scores indicate greater pain severity (worse outcome).	Within 24 hours after surgery

Collaborators and Investigators

• Sponsor: Min Li

Study record dates

Study Major Dates

• Study Start (Actual): April 16, 2026
• Primary Completion (Actual): April 25, 2026
• Study Completion (Actual): April 25, 2026

Study Registration Dates

• First Submitted: April 23, 2026
• First Submitted That Met QC Criteria: April 23, 2026
• First Posted (Actual): April 30, 2026

Study Record Updates

• Last Update Posted (Actual): May 8, 2026
• Last Update Submitted That Met QC Criteria: May 4, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative
• Other Study ID Numbers: M20260277

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No