cases of restriction. Traditionally, Achilles tendon lengthening has been performed
through open surgery using Z lengthening or sliding techniques, or percutaneously with
2-3 partial cuts using a scalpel. However, these methods may lead to scarring and other
complications that some find troublesome.
A novel technique for Achilles tendon lengthening involves the needle technique, which
applies a series of percutaneous microtenotomies to the tendon using needle pricks. These
microtenotomies gradually weaken and stretch the tendon to the desired length without
necessitating the opening of the skin or tendon sheath, thus avoiding scar formation.
This modified technique may offer potential advantages over traditional methods, yet
there is limited research in this area. It is also unknown how the Achilles tendon
reorganizes anatomically following needle lengthening. The technique is similar to that
used in the percutaneous release of Dupuytren's contracture, and several reports have
emerged on the use of this method for Achilles tenotomy in the treatment of clubfoot.
Ultrasound-guided needle techniques for gastrocnemius recession have also been reported.
We have utilized this technique in approximately 200 patients over the past few years
with positive experiences, both in terms of surgical technique and clinical outcomes.
Patients predominantly report positive experiences with significant benefits from the
lengthening.
The purpose of this study is to evaluate the needle technique as a surgical method for
Achilles tendon lengthening in children and adolescents. The study will assess the
efficacy, feasibility, and safety of the percutaneous needle technique for Achilles
tendon lengthening in pediatric patients. The study aims to contribute to the knowledge
of a new and likely more benign surgical method for treating equinus foot deformities in
children and to evaluate whether the needle technique can be a safe, effective, and
feasible alternative to existing treatments.
Objective:
To compare the efficacy and safety of two surgical techniques (needle technique vs.
standard Z-plasty) for Achilles tendon lengthening in pediatric patients aged ≥ 5 to ≤ 16
years.
Study Design:
A prospective observation of a cohort of young patients undergoing Achilles tendon
lengthening using the needle technique over a two-year period.
Sample Size:
Up to 50 patients will be recruited, or as many as consent to participate during the
two-year study period. No significant differences regarding the effect of the procedure
are expected. Since the occurrence of complications following this type of surgery is
very rare, the sample size is determined at discretion. A sample size based on
statistical calculations to ensure the study's ability to detect meaningful differences
in the study group compared to historical findings would necessitate an impractically
large group of patients.
Methods
Procedure:
Percutaneous Achilles tendon lengthening with the needle technique is performed by
applying a series of microtenotomies to the tendon using needle pricks while the tendon
is stretched. A withdrawal needle with a diameter of 1.1-1.2 mm is used. The needle
pricks gradually weaken the tendon and stretch it to the desired length without opening
the skin or tendon sheath. As a rule, it is desirable to achieve approximately 10-15
degrees of dorsiflexion before concluding the lengthening.
Local infiltration anesthesia is applied, followed by a simple bandage. The surgical
procedure typically takes 3-4 minutes. Finally, a boot cast in soft plaster with the foot
and ankle in neutral position is applied, and it can be fully weight-bearing immediately.
The cast is removed at the clinic after 4 weeks. After cast removal, the child/adolescent
should be allowed gentle activity - not sports - for another 4 weeks, thereafter
unrestricted activity.
Physical therapy may be utilized as needed, locally. Radiology Routine conventional
radiographs of the feet/ankles are not taken. Ultrasound examination is conducted just
before and one year after the procedure.
Ultrasound Method: Use of a high-frequency linear transducer for accurate assessment of
the Achilles tendon.
Clinical Examination The tests and measurements are standardized and conducted by two
experienced testers (pediatric physiotherapists) using a goniometer. The patients are
lying on a bench during the examination. In cases of doubt or uncertain measurements, the
examinations are repeated as many times as necessary and the average is used. Strength
testing is performed before and one year after the operation with a handheld dynamometer.
An orienting neurological examination, i.e., assessment of spasticity (MAS), reflex
Preliminary Neurological Examination, i.e., assessment of spasticity (MAS), reflexes,
clonus, is performed prior to the surgery to uncover any underlying neurological
condition.
Quality of Life A validated translated version of the generic PedsQL scale will be used
to assess the patients' HRQoL, based on age (18-20). Self-reports will be used for
patients aged 5-7, 8-12, and 13-18 years. Parent-proxy reports will be used for the ages
of 5-7, 8-12, and 13-18. Parents will complete the parent-proxy report independently from
the patient and in separate rooms. PedsQL score reports will be completed during
preoperative and 1-year follow-up assessments.
Data Collection:
Data will be collected before the procedure, and at 4 weeks, 6 months, and one year after
the procedure at specified follow-up intervals. Standardized forms for data collection
will be used to ensure uniformity in data collection.
Statistical Analysis:
Paired t-tests will be used for comparison of continuous and normally distributed data.
Fisher's exact test will be used for comparison of dichotomous parameters. SPSS 28 will
be used for data analysis, and a p-value <0.05 will be considered statistically
significant.
Project Organization and Data Storage:
The study is conducted by the project group at the Department of Orthopedics, Drammen
Hospital. The project group holds the data necessary for the study and owns the data.
Nettskjema is used for data collection, and the data are stored on Medinsight on a secure
research server. During the study, indirectly identifiable information is stored on the
research server in the Research Portal for HSØ, where all project participants have
access. The code list is stored separately from these and locked in a secure, locked
cabinet (safe).
Ethics and Consent:
The study will be conducted in accordance with the Helsinki Declaration and local ethical
guidelines. Applications will be made to the Regional Committees for Medical and Health
Research Ethics (REK) and the Data Protection Officer (PVO) in VV. Informed consent for
participation, data use, and publication permission will be obtained from
parents/guardians (all participants are under 16 years), and information letters will be
prepared and distributed to the children according to age (5-12, 12-16).
See attached consent form.
Study Registration:
The study will be registered in a recognized clinical study registry to ensure
transparency.
Patient recruitment is planned to start in the fall of 2024. A 2-year inclusion period is
estimated, meaning inclusion is expected to be completed by the fall of 2026. If
necessary, an extension of the study period will be requested from REK and PVO. Data
collection at follow-up, etc., is estimated to be completed by the fall of 2027.