Semitendinosus Autograft vs Meniscal Allograft in Post-Meniscectomy Syndrome (MAT)

Chang Gung Medical Foundation

Status: Not yet enrolling

Conditions: Meniscal Injuries; Meniscus Lesion; Meniscal Tear

Treatments: Procedure: Autologous Semitendinosus Tendon Graft; Procedure: Meniscal Allograft Transplantation (MAT)

Study type: Interventional

Funder types: Other

Identifiers

NCT07204587

ChangGungMH MeniscusTransplant

Details and patient eligibility

About

This multicenter, stratified, partially randomized clinical trial aims to compare autologous semitendinosus tendon graft and meniscal allograft transplantation (MAT) in young adults with post-meniscectomy syndrome. The meniscus plays a critical role in load distribution, shock absorption, and joint stability. After meniscectomy, insufficient meniscal tissue often leads to persistent pain, swelling, and functional decline, increasing the risk of early osteoarthritis.

Two reconstructive strategies are clinically available: MAT provides immediate biomechanical function but requires donor matching and carries higher costs, while autologous tendon graft offers stable supply and no immunologic risk but lacks long-term clinical validation.

In this study, 40 patients aged 18-45 years will be enrolled. Participants will be allocated into four groups (randomized MAT, randomized autograft, patient-preference MAT, patient-preference autograft). All procedures will use a two-tunnel fixation technique with additional internal brace support.

The primary endpoint is the improvement in KOOS (Knee Injury and Osteoarthritis Outcome Score) at 24 months postoperatively. Secondary endpoints include MRI-based assessment of graft morphology and extrusion, reoperation rate, complications, patient satisfaction, and return-to-sport time.

This trial will provide critical evidence regarding the comparative effectiveness and feasibility of tendon autograft versus meniscal allograft in real-world clinical settings, potentially informing surgical decision-making and future treatment guidelines for post-meniscectomy syndrome.

Full description

Post-meniscectomy syndrome represents a challenging condition in young adults, characterized by persistent pain, swelling, and functional impairment after partial or subtotal meniscectomy. The lack of sufficient meniscal tissue predisposes patients to abnormal tibiofemoral loading and early onset osteoarthritis. Current reconstructive options remain limited, and there is no consensus on the optimal surgical strategy.

Meniscal allograft transplantation (MAT) has been the most widely accepted method, offering immediate restoration of meniscal morphology and load-distributing capacity. However, MAT is constrained by donor availability, graft costs, and local regulations. In contrast, autologous tendon grafts-most commonly using semitendinosus-are readily available, carry no risk of rejection, and reduce cost barriers. Early biomechanical and translational studies suggest that autologous tendon grafts may adapt to meniscal-like properties, yet long-term clinical data remain scarce.

This trial employs a stratified, partially randomized design to balance methodological rigor with patient autonomy and ethical feasibility. Participants are assigned to autologous tendon graft or MAT either through randomization or patient preference, allowing assessment of outcomes under both controlled and real-world conditions. All procedures are standardized across participating centers, utilizing a two-tunnel fixation technique and augmented with an internal brace (Fibertape) to enhance graft stability.

Outcomes will be assessed over 24 months, including validated patient-reported measures (KOOS, IKDC, Tegner), MRI-based graft evaluation (volume, signal, extrusion, morphology), reoperation rates, complications, satisfaction, and return-to-sport. By integrating randomized comparison with pragmatic elements, this study aims to generate clinically applicable evidence on the relative benefits and limitations of autologous tendon graft versus MAT. The findings are expected to inform surgical decision-making, optimize patient outcomes, and guide future treatment recommendations for young patients suffering from post-meniscectomy syndrome.

Enrollment: 40 estimated patients

Sex: All

Ages: 18 to 45 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Adults aged 18 to 45 years

History of partial meniscectomy > 6 months prior to enrollment

Symptomatic post-meniscectomy syndrome (knee pain, swelling, or functional decline)

MRI showing cartilage status ≤ Outerbridge grade 2

Knee joint stability (or stabilized during the index surgery)

Body mass index (BMI) < 30

Willingness to provide written informed consent

Exclusion criteria

Tibial slope > 16°

Radiographic or arthroscopic evidence of advanced cartilage degeneration (Outerbridge > 2 or ICRS ≥ 3)

Presence of inflammatory arthritis or systemic inflammatory joint disease

History of cartilage repair surgery

Malalignment > 5° not corrected

Untreated ligamentous instability

Any other condition judged by the investigator to compromise study participation or outcomes

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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40 participants in 4 patient groups

A1 Autologous Semitendinosus Tendon Graft (Randomized)

Experimental group

Description:

Patients randomized to this arm will undergo meniscal reconstruction using autologous semitendinosus tendon grafts (diameter ≥ 6 mm). Standard two-tunnel fixation technique will be applied, with Fibertape internal brace augmentation. ACL reconstruction may be performed simultaneously if indicated.

Treatment:

Procedure: Autologous Semitendinosus Tendon Graft

A2 Meniscal Allograft Transplantation (Randomized)

Experimental group

Description:

Patients randomized to this arm will receive size-matched fresh-frozen meniscal allografts. Fixation will be performed using the standard two-tunnel technique.

Treatment:

Procedure: Meniscal Allograft Transplantation (MAT)

Meniscal Allograft Transplantation (Patient Preference)

Experimental group

Description:

Patients who decline randomization but choose allograft transplantation will undergo the same surgical procedure as Arm A2, with fresh-frozen meniscal allografts.

Treatment:

Procedure: Meniscal Allograft Transplantation (MAT)

Autologous Semitendinosus Tendon Graft (Patient Preference)

Experimental group

Description:

Patients who decline randomization but choose autologous tendon grafting will undergo the same procedure as Arm A1, using semitendinosus tendon grafts with Fibertape internal brace augmentation.

Treatment:

Procedure: Autologous Semitendinosus Tendon Graft