Evidence-Guided Orthobiologics in PM&R: Practical Patient Selection, Technique, and Rehab Pearls

Educational webinar recap (December 2025) featuring Mark Gruner, DO, MBA, RMSK

In an educational session hosted by APEX Biologix, Mayo Clinic–trained interventional sports physiatrist Mark Gruner, DO, MBA, RMSK shared an evidence-based, clinic-ready framework for integrating orthobiologics into PM&R and sports medicine workflows. The discussion focused on how Dr. Gruner approaches patient selection, ultrasound-guided technique, adjunct biologic options (including Protein Concentrate/A2M), and structured rehab with the goal of increasing responder rates and improving consistency across common musculoskeletal presentations.

How Dr. Gruner explains PRP to patients 

In Dr. Gruner's session, he emphasized a simple, repeatable explanation: PRP is created by drawing autologous blood, centrifuging it, and concentrating platelets - delivering growth factors that influence the local healing environment. In his practice, this sets the stage for informed consent while keeping expectations grounded.

For joint disease, he underscored that PRP is best positioned as a tool to:

• support pain reduction and improved function

• help down-regulate inflammatory signaling

• potentially offer cartilage-protective effects (without claiming cartilage “regeneration”)

He noted that while tendon biology differs from joint pathology, aligning the biologic choice with the tissue problem - and the structural stability of that tissue - is a recurring theme throughout his algorithms.

Responder rate improves when you define the right use cases

A core theme in the session was that outcomes improve when practices standardize indications and exclusions. He shared that by developing internal referral criteria and tracking outcomes through a registry approach, his team increased responder rates over time - moving from roughly “good” results to more consistently high response across selected indications.

Common high-yield PRP indications 

Dr. Gruner outlined clinical scenarios where PRP tends to perform well, particularly when imaging and mechanics align with the pain generator:

Upper extremity

• low-grade/interstitial rotator cuff tears

• mild–moderate shoulder arthritis in appropriate morphologic patterns

• lateral epicondylopathy (tennis elbow) and medial epicondylopathy (golfer’s elbow)

• mild–moderate thumb CMC arthritis

Lower extremity

• hip OA (generally Tönnis ≤2) and carefully selected labral pathology

• gluteus med/min tendinopathy and partial tearing

• hamstring tendinopathy (distinguishing tendon vs muscle targets)

• mild–moderate knee OA (especially KL1–2; selective KL3 criteria)

• patellar/quad tendinopathy

• focal mid-portion Achilles tendinopathy and selected plantar fasciosis cases

Rotator cuff pearls: stability, tear location, and scaffold decisions

For cuff pathology, Dr. Gruner emphasized that “partial tear” is not one diagnosis. He described three practical decision points:

1. Tear grade and geometry

• Low-grade partial tears (<50%) may be reasonable PRP candidates when stability is preserved.

• As tears become high-grade or demonstrate instability patterns, outcomes become less predictable.

2. Where the tear sits matters
   He highlighted that tears drifting toward the rotator interval and stabilizing ligaments may behave more “unstable,” particularly when biceps mechanics are affected—changing the risk profile and expectations.

3. When to add “scaffold” support
   In cases where the tissue problem is more than inflammatory tendinopathy, i.e., true partial tearing, he described using PRP combined with a more viscous biologic substrate (such as Protein Concentrate/A2M) in select patients, based on the clinical picture and imaging.

Post-op augmentation in rotator cuff repair

Dr. Gruner also reviewed that some studies and meta-analyses suggest PRP augmentation in the early post-op window may help reduce re-tear rates and improve short-term outcomes while emphasizing technique precision to avoid disrupting repairs.

Shoulder arthritis: move beyond mild/moderate/severe

A clinician-ready point: Dr. Gruner advised classifying shoulder arthritis more precisely (rather than only “severity”) to predict whether orthobiologics are likely to help.

He discussed how glenoid morphology and humeral head centering influence outcomes - suggesting that once structural imbalance or posterior wear patterns become pronounced, biologic injections may not overcome mechanics.

Practical technique note: he frequently aspirates effusion before injection to reduce inflammatory load and improve the environment for the biologic.

Tennis & golfer’s elbow: ultrasound mapping is the procedure

Dr. Gruner reinforced that tendinopathy care improves when clinicians treat the problem as 3D pathology rather than a single painful point. His process includes:

• measuring tear length and width

• using fluid distension to reveal occult tearing

• using power Doppler to identify neovascularity and inflammatory patterns

• treating both the tear and the “biology” around it, rather than only the insertion footprint

He also reviewed where percutaneous tenotomy (e.g., Tenex) can be appropriate—particularly in tendinopathy without major tearing, and in calcific cases where debridement is part of the solution set.

Hip OA: classify arthritis and the bony problem

For hip injections, Dr. Gruner stressed that Tönnis grading alone isn’t enough. His screening includes:

• Tönnis grade (often focusing on ≤2)

• presence of large cam/pincer deformities, dysplasia angles, and displaced labral tears

• differentiating “arthritic pain” from “structural impingement pain”, where PRP may be limited

He described modifying targets (joint vs labrum) depending on age, imaging, and exam patterns.

Knee OA: dose awareness, effusion management, and the “recurrent swelling” subset

Dr. Gruner noted that knee OA is the most studied PRP indication, and he pointed to several evidence reviews and professional guidance documents supporting PRP in mild–moderate OA, especially when dose is adequate.

Key clinical pearls he emphasized:

• aspirate effusion whenever present before injecting

• consider BMI, malalignment, and subchondral edema as outcome modifiers

• patellofemoral OA behaves more like a compression-driven pain problem and can be less responsive depending on anatomy (e.g., alta/baja)

When to consider PRP + Protein Concentrate (A2M)

In the specific subgroup of recurrent effusion/swelling without another structural driver, Dr. Gruner described using PRP + A2M Protein Concentrate (A2M) (sometimes paired with HA) and noted clinically meaningful improvement in swelling and symptoms in select cases - presented as a practice-based observation aligned with the proposed anti-protease mechanism (MMP modulation).

Tendon rehab: the biologic is not the whole treatment

One of the most transferable clinician takeaways: Dr. Gruner repeatedly emphasized that outcomes depend on pairing injections with structured loading and staged rehab.

He reviewed the concept of tendon healing phases:

• early inflammatory window (often a few days of expected symptom flare)

• proliferative phase (weeks)

• remodeling phase (weeks to months)

He noted that patient education, especially around realistic timelines, reduces “false failures” and improves adherence.

Key take-home algorithm 

Dr. Gruner’s throughline was consistent: match the biologic to tissue type, stage, and mechanical reality.

• PRP: strong fit for many mild–moderate OA and tendinopathies, especially with ultrasound-defined targets

• PRP + Protein Concentrate (A2M): considered where inflammatory milieu or recurrent swelling may warrant additional strategy

• Microfragmented adipose / other higher-structure options: considered when scaffold/structural support is a priority or when disease is more advanced

• Percutaneous tenotomy / tendon scraping: considered for tendinopathy phenotypes where debridement of degenerative tissue and neovascular drivers are central

Watch the full educational webinar 

Want the complete clinical walkthrough - including Dr. Gruner’s ultrasound technique examples, selection nuances (e.g., shoulder morphology, occult tearing), and rehab progression logic?  Access the full webinar replay in the APEX Resource Library 

References

Prodromos, C., et al. Treatment of rotator cuff tears with platelet rich plasma: a prospective study with 2 year follow‐up. BMC Musculoskeletal Disorders. 2021;22:499. doi:10.1186/s12891-021-04288-4

Bohlen, H., et al. Platelet-Rich Plasma Is an Equal Alternative to Surgery in the Treatment of Type 1 Medial Epicondylitis. Orthopaedic Journal of Sports Med. 2020;8(3):e2325967120908952. doi:10.1177/2325967120908952

Lim, A., et al. The use of intra-articular platelet-rich plasma as a therapeutic intervention for hip osteoarthritis. The American Journal of Sports Medicine. 2023;51(9):2487–2497. doi: 10.1177/03635465221095563

Oeding, J., et al. Platelet-rich plasma versus alternative injections for osteoarthritis of the knee: A systematic review and statistical fragility index-based meta-analysis of randomized controlled trials. The American Journal of Sports Medicine. 2024;52(12):3147–3160. doi:10.1177/03635465231224463

Disclaimer

This blog post is a summary of an educational session and is provided for informational purposes for healthcare professionals. The perspectives shared reflect the clinical experience and opinions of the speaker(s) and do not necessarily represent the views of APEX Biologix. This content is not medical advice and is not intended to establish a standard of care, diagnose, or recommend treatment for any individual patient. Clinicians should evaluate all therapies using their independent clinical judgment, applicable regulations, and the most current evidence.