Sports MedicineShoulderSurgery Center

Arthroscopic Repair of Partial Thickness Rotator Cuff Tear

Performed by Drs. Raffo and Christoforetti, fellowship-trained shoulder surgeons offering bioinductive implant augmentation for partial-thickness rotator cuff tears at our ambulatory surgery center.

Duration: 45–75 minutesAnesthesia: General with nerve block

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What is Arthroscopic Repair of Partial Thickness Rotator Cuff Tear?

Arthroscopic repair of a partial thickness rotator cuff tear treats a tendon injury that has not torn all the way through. High-grade tears are often repaired using a bioinductive collagen implant that stimulates new tendon growth, or by completing and repairing the tear with anchors. Recovery is typically faster than full-thickness repair.

Why this approach — at MOS

We evaluate every partial-thickness tear on its own merits rather than applying a single default technique. The tear's grade, location, and the quality of the surrounding tissue, assessed directly during arthroscopy, guide whether bioinductive augmentation or a takedown-and-repair approach is the better fit for a given patient and a given tear.

For appropriately selected high-grade tears, we favor bioinductive augmentation when the intact portion of the tendon is substantial enough to preserve. Avoiding an unnecessary takedown of healthy tendon fibers, while still directly addressing the area of damage, aligns with our broader philosophy of matching the surgical intervention to the actual extent of the pathology rather than defaulting to the most familiar technique.

What the Evidence Shows

The evidence base for treating high-grade partial-thickness tears has matured substantially, including a direct head-to-head randomized trial.

A foundational prospective multicenter study of 33 patients with intermediate- and high-grade partial tears treated with the bioinductive implant found that tendon thickness increased by a mean of 2.0 millimeters on MRI, with eight patients showing complete healing and twenty-three showing a considerable reduction in defect size. Only one patient progressed to a full-thickness tear, and that patient had sustained a new injury while shoveling snow rather than experiencing treatment failure (Schlegel et al., JSES, https://pubmed.ncbi.nlm.nih.gov/29157898/).

The most direct evidence comes from a 2026 prospective randomized trial that compared bioinductive implant augmentation against standard takedown-and-repair in 41 patients with high-grade partial tears. The Regeneten group recovered meaningfully faster in every early milestone measured: sling removal at roughly two and a half weeks versus five weeks, return to driving in about two and a half weeks versus five weeks, and return to moderate household activity in under four weeks versus more than eight weeks, all statistically significant differences. By six and twelve months, both groups had converged to excellent and statistically equivalent function, and MRI at twelve months showed equivalent tendon healing between the two approaches, with no full-thickness tears or structural failures in either group (Wang et al., OJSM, https://pmc.ncbi.nlm.nih.gov/articles/PMC12961150/).

A pooled meta-analysis of thirteen studies found the retear rate for partial-thickness tears treated with the bioinductive implant to be low, roughly one percent. Adverse reactions to the implant itself were rare, occurring in a small fraction of a percent of cases across the pooled data (Warren et al., JSES, https://pubmed.ncbi.nlm.nih.gov/38942225/).

Taken together, this evidence supports bioinductive augmentation as a technique that reaches the same durable, one-year outcome as traditional repair for appropriately selected high-grade partial tears, while offering a meaningfully faster early recovery.

Who is a candidate?

Indications

High-grade partial-thickness tear (involving more than half the tendon thickness) confirmed on MRI
Persistent pain, weakness, or night pain that has not improved after a structured course of physical therapy
A tear that has progressed in size on follow-up imaging
An intermediate-grade tear with significant functional limitation despite appropriate non-operative care

Contraindications

Low-grade or intermediate-grade tears without significant symptoms, which are generally managed with physical therapy rather than surgery
Active shoulder infection
Severe medical comorbidities that make anesthesia unsafe
Patients unwilling to comply with post-operative activity restrictions

Conservative Treatment First

The great majority of partial-thickness tears do well without surgery. Physical therapy focused on rotator cuff and periscapular strengthening, activity modification, and anti-inflammatory medication relieves pain and restores function in most patients, and this should be the first approach for low- and intermediate-grade tears. A corticosteroid injection may be used selectively to calm an acute flare and allow more effective participation in therapy, though it is not recommended as a routine treatment for tendon degeneration itself.

Surgery is considered when a high-grade tear has failed a genuine trial of therapy, typically a minimum of three months, or when imaging shows the tear has progressed toward full thickness. Not every partial tear that appears on imaging requires treatment. Many are found incidentally and never become symptomatic, which is why decisions are based on the combination of tear grade, imaging findings, and how much the tear is actually limiting the patient.

The procedure

What Is a Partial Thickness Rotator Cuff Tear?

A partial thickness rotator cuff tear is damage to a rotator cuff tendon, most often the supraspinatus, that does not extend completely through its thickness. Picture the tendon as a rope made of many parallel fibers. In a partial tear, some of those fibers have failed while others remain intact, so the tendon stays attached to the bone but is thinner, weaker, and often painful. A full thickness tear, by contrast, means the fibers have failed all the way through, and the tendon has lost its footprint on the bone entirely.

This distinction matters because it changes both the treatment and the surgical goal. A full-thickness tear must be reattached to bone, because there is no tendon-to-bone connection left to preserve. A partial tear often still has a healthy connection to the bone that can be protected and reinforced rather than taken apart and rebuilt. That difference is the reason a partial tear and a full tear are treated differently in the operating room, and it is why many partial tears can be managed with a shorter recovery than a standard repair.

Surgeons grade partial tears by how much of the tendon's thickness is involved: low-grade tears involve less than 25% of the thickness, intermediate-grade tears involve 25-50%, and high-grade tears involve more than 50%. Tears are also described by location. Most occur on the articular side, the undersurface of the tendon facing the joint, in a region with relatively limited blood supply that makes it more prone to degeneration with age. A smaller share occur on the bursal side, the outer surface, or within the substance of the tendon itself.

The Science of the REGENETEN Bioinductive Implant

The REGENETEN implant (Smith and Nephew) is a resorbable collagen scaffold derived from purified bovine Achilles tendon. Unlike a traditional graft or patch, which simply provides mechanical reinforcement, this implant is bioinductive, meaning it actively stimulates the body to grow new tendon tissue rather than acting as a permanent structural bridge.

The scaffold's highly porous architecture allows the patient's own fibroblasts and tendon-forming cells to migrate into it soon after implantation. Human biopsy studies have tracked this process directly. At five weeks, biopsies show host cells populating the implant and aligning along its fiber structure with early collagen formation. By three months, that collagen has matured and organized further. By six months, biopsies show newly formed tissue with the histologic appearance of mature tendon, and the implant itself has been fully resorbed, with no remnant of the original scaffold detectable (Arnoczky et al., Arthroscopy, https://pubmed.ncbi.nlm.nih.gov/27650821/).

In practical terms, the implant is not left behind as foreign material. It functions as a temporary scaffold that guides the body to rebuild its own tendon, then disappears once that new tissue has formed. Follow-up MRI studies have consistently shown measurable increases in tendon thickness beginning around six months after implantation, consistent with this biological healing process.

The implant is placed arthroscopically, typically as a brief addition of about 5-10 minutes to the overall procedure. It is fixed over the area of tendon thinning using a combination of small anchors, without the need to complete or otherwise disrupt the intact fibers on the opposite side of the tendon.

What Happens During Surgery

Before Surgery

You will arrive at the ambulatory surgery center approximately 90 minutes before your scheduled procedure. A pre-operative interscalene nerve block is placed while you are awake but lightly sedated, numbing the shoulder and arm for 12 to 18 hours and significantly reducing pain in the immediate post-operative period.

Diagnostic Arthroscopy

After general anesthesia is administered and you are positioned in the beach chair or lateral decubitus position, small incisions are made and the arthroscope is inserted to inspect the joint. The surgeon evaluates the tear's exact location, size, and depth, which is confirmed directly in a way that MRI can approximate but not always fully capture.

Choosing the Surgical Approach

Two main strategies exist for a high-grade partial tear that requires surgery, and the choice depends on the tear's characteristics and the surgeon's judgment at the time of arthroscopy.

The first is bioinductive implant augmentation, in which the intact portion of the tendon is left undisturbed and the collagen scaffold is fixed to the outer surface of the tendon over the area of thinning, reinforcing it and stimulating new tissue growth without converting the tear into a full-thickness defect.

Takedown-and-repair, in which the surgeon completes the tear into a full-thickness defect and then performs a standard suture anchor repair, is also performed in some cases.

The best available comparative research has not shown one approach to be clearly superior to the other in long-term healing or function. What the evidence does show clearly is that bioinductive augmentation tends to involve a shorter procedure and a notably faster early recovery, while both approaches reach similar functional outcomes and similar tendon healing on MRI by one year.

Closure and Recovery Room

Portals are closed with sutures or skin tape, and the arm is placed in a sling appropriate to the technique used. You spend 45 to 60 minutes in the recovery room before discharge, typically going home within two hours of the procedure ending.

Recovery timeline

Days 0 to 14 (Initial Protection)

Sling use for comfort and protection, with the exact duration depending on the technique used. Elbow, wrist, and hand motion begin immediately to prevent stiffness.

Weeks 2 to 4 (Early Motion)

Patients treated with bioinductive augmentation alone typically progress out of the sling and into gentle motion during this window, considerably sooner than a standard repair allows.

Weeks 4 to 8 (Progressive Strengthening)

Active motion and early strengthening begin as tolerated, guided by your surgeon and physical therapist based on your specific procedure.

Months 2 to 4 (Functional Return)

Return to office work, driving, and most household and daily activities is typically complete during this window.

Months 4 to 6 (Return to Full Activity)

Return to sport and more demanding physical activity, with overhead athletes generally requiring the longer end of this range.

Recovery pace depends heavily on which surgical technique was used. Patients treated with bioinductive implant augmentation alone generally progress faster in the early months than patients whose tear was completed and repaired with anchors, because there is no bone-to-tendon healing that must be protected in the same way. By six to twelve months, however, both approaches typically reach similar functional outcomes.

Our physical therapy team, co-located with our surgical practice, tailors the rehabilitation protocol to the specific technique performed during your surgery. Consistent attendance and following activity restrictions during the early weeks remain the most important factors in a smooth recovery, regardless of which technique was used.

Frequently Asked Questions

What is the difference between a partial and full thickness rotator cuff tear?

A partial thickness tear involves only some of the tendon's fibers, leaving the tendon still attached to the bone, while a full thickness tear extends completely through the tendon and separates it from its bony attachment. This distinction changes the surgical goal. A full tear must be reattached to bone with anchors, while a partial tear with an intact bone attachment can often be reinforced and protected rather than taken apart and rebuilt.

Do all partial thickness tears need surgery?

No. Most partial thickness tears, particularly low-grade and intermediate-grade tears, improve with physical therapy, activity modification, and time. Surgery becomes a reasonable option when a high-grade tear, involving more than half the tendon's thickness, has failed a genuine trial of therapy of at least three months, or when the tear is shown to be progressing on follow-up imaging.

What is the REGENETEN implant, and is it a permanent implant?

No, it is not permanent. The REGENETEN implant is a resorbable collagen scaffold that stimulates your own body to grow new tendon tissue over the damaged area. Biopsy studies have shown that by six months after surgery, the implant has been completely absorbed and replaced by tissue with the appearance of mature tendon. It functions as a temporary biological scaffold, not a lasting foreign material.

Is recovery faster with the bioinductive implant compared to a standard repair?

Yes, in the early months. A randomized trial directly comparing the two approaches for high-grade partial tears found that patients treated with the bioinductive implant returned to sling removal, driving, and household activities roughly twice as fast as patients whose tear was completed and repaired with anchors. By six to twelve months, however, both groups reached similar, excellent outcomes and had equivalent tendon healing on MRI.

How do you decide between the implant and completing the tear for repair?

The decision is made based on the tear's grade, location, and the quality of the surrounding tendon tissue, which is assessed directly during arthroscopy. When a substantial portion of healthy tendon remains intact, augmenting it with the bioinductive implant preserves that healthy tissue while still treating the area of damage. When tissue quality is poor or the tear pattern makes augmentation less suitable, completing the tear and performing a standard anchor repair may be the more reliable choice.

Will my rotator cuff tear get worse if I don't have surgery?

Not necessarily. Reported progression rates for partial thickness tears vary widely across studies, and many partial tears remain stable for years without treatment. Higher-grade tears, involving more than half the tendon thickness, are generally considered more likely to progress than low-grade tears, which is one reason surgery is considered more readily for high-grade tears that are also symptomatic.