Alberto Abrebaya DPM, DABPS, FAPWCA

AmnioFix regenerative injection in Achilles

Tendinopathy

Abstract

Objective: To discern the efficacy of Micronized Amniotic Membrane Allograft in Tendoachilles enthesopathy and tendinopathy.

Background:Injectable Micronized Amniotic Membrane Allograft has been used for multiple musculoskeletal anomalies with proven clinical success. In the Tendoachilles for varying anatomical reasons, the anatomy is subject to tendinosis, insertional enthesitis and intrasubstance tears with tendinopathy. AmnioFix delivers essential growth factors and extracellular Matrix Proteins, collagen , reduces Inflammation, improves functional rates and subjective pain scales from enhanced soft tissue healing. Methods: Twenty-six feet of 32 consecutive patients with MRI-evidenced Achilles tendinosis and tendinopathy of moderate to high degree were injected with a solution of 1.25 G of micronized amniotic membrane reconstituted in 2mL of 1% Lidocaine plain.

Results: Except for one Tendoachilles with inflammatory arthritis, all patients reported an significant improvement in subjective pain and functionality. In addition, Phenotypic clinical markers of inflammation ~ induration of the Tendoachilles, as well as functional parameters such as forcible end range of motion, and overall tension stress of the Tendoachilles during normal ambulation were essentially resolved to date. Treatment parameters involved initial evaluation consultation for pain in the region. Radiographic and magnetic resonance imaging scans were also obtained when possible. Treatment with reconstituted micronized amniotic membrane allograft was initiated in the second or third subsequent visits approximately thirty 30- to forty-five 45 days post initial diagnosis. The technique for injection was preceded by antisepsis of the injection site involved and placement of sterile field. A hypodermic injection using a sterile 25 or 27 G needle through the substance of the Tendoachilles into the previously identified pathologic region of hypertrophic tendinopathy at the critical zone and/or the insertional enthesopathic region.

ConclusionsInjection of micronized amniotic membrane appears effective for the treatment of Tendoachilles musculoskeletal anomalies including insertional enthesopathy, tendinosis with tendinopathy of the critical zone in patients ranging from their third to seventh decade of life. As traumatization of the mesotenon and endotenon occur from either biomechanical strain or chronic localized ischemia in the “watershed” or critical zone” as in the case of repetitive microtraumatization, anatomical Soleus muscle deficiency whereby musculotendinous junction occurs high above the bottom half of the calf, the resulting tendinosis is typically irreversible. In the majority of cases, fibrosis and scarring result in dysfunction and pain. In others, injury undergoes chronic tendinopathy and degeneration of the endotenon which evolves into a necrotic nidus of degenerate collagen fibers, mucomyxoid degeneration, which further deteriorate into substance tears with degradation of the tendon strength and elasticity. These subjects may be best suited for injection of regenerative tissue implantation by methods such as micronized amniotic membrane allograft injection. Osteotripsy has been documented effective for the non-surgical treatment of calcific insertional Tendoachilles enthesitis, epicondylitis and plantar fasciitis. Radiofrequency ablation has been documented with limited long term success in the surgical treatment of plantar fasciosis and Tendinosis of the Achilles tendon. However few, if any minimally or non-invasive methods have been documented effective in mitigating the pain and dysfunction for the treatment of tendinosis with tendinopathy.

Client No Age

LateralityDiagnosis

Pain Rating

Activity rating

Functionrating

Total Administered dose

1 CA 67 left TENDINOSISENTHESOPATHY

Start—Finish8 2

Start—Finish1 5

Start—Finish1 5

1.25 G

2 TV 59 right TENDINOPATHYSUBSTANCE TEAR

8 1 2 5 2 5 1.25 G

3 GF 52 right and left

TENDINOSISENTHESOPATHY

7 0 2 5 2 5 1.25 G

4 RA 41 right and left

TENDINOSISENTHESOPATHY

10 2 1 5 1 5 1.25 G

5 FL 58 right and left

TENDINOSISENTHESOPATHY

9 1 0 4 0 4 1.25 G

6 MO 48 right and left

TENDINOPATHYSUBSTANCE TEAR

7 1 1 5 1 5 1.25 G

7 DU 43 right TENDINOPATHYSUBSTANCE TEAR

9 2

0 4 0 4 1.25 G

8 DA 41 right and left

TENDINOSISENTHESOPATHY

7 0 1 4 1 4 1.25 G

9 KN 59 left TENDINOSISENTHESOPATHY

8 1 0 4 0 4 1.25 G

10 PR 55 right and left

TENDINOPATHYSUBSTANCE TEAR

8 2 1 5 1 5 1.25 G

11 WL 59 right and left

TENDINOSISENTHESOPATHY

9 3 0 4 0 4 1.25 G

12 FK 66 right TENDINOPATHYSUBSTANCE TEAR

8 2 0 5 0 5 1.25 G

13 SC 53 right TENDINOSISENTHESOPATHY

10 1

1 5 1 5 1.25 G

14 MT 45 right and left

TENDINOSISENTHESOPATHY

9 3

1 4 1 4 1.25 G

15 HU 64 right and left

TENDINOPATHYSUBSTANCE TEAR

8 1 0 4 0 4 1.25 G

16 TL 72 right and left

TENDINOSISENTHESOPATHY

10 2 1 5 1 5 2.0 G

          Total  26 Tendons

One Patient received a second injection during the care regimen for persistent disabling calcific insertional enthesopathy and tendinopathy though symptoms mitigated at the 6th week interval. Initial reaction to amniotic allograft injection produced a paroxysmal 24 hour initial phase whereby an inflammatory infiltrate produced pain, hyperemia, and swelling of the injected areas. (On one rare occasion, a localized atopic urticaria was documented, but likely related to hypersensitivity to Coban compressive dressing rather than the amniotic allograft). This phase lasted approximately 48 to 72 hours without clinical evidence of graft-host rejection. The first, 8 tendons where treated with a protocol of Patient education and rest, ice, compression and elevation (R.I.C.E.) recommendations. Afterward, our protocols changed whereby Patients were placed on rigid ankle walking braces for protected weighted ambulation, and prescription of enteral narcotic analgesics if necessary. NSAIDs were withheld during treatment to avoid masking the effects of the amniotic allograft to the affected areas for objectively quantifying the benefit of treatment.

PREPARATION OF PRESERVED HUMAN AMNIOTIC MEMBRANEHuman amniotic membrane was prepared and preserved using a method described elsewhere.14- 15 In brief, the human placenta was obtained shortly after an elective cesarean section when the human immunodeficiency virus, human hepatitis type B and C, and syphilis had been excluded by serologic tests. Under a laminar flow hood, the placenta was cleaned of blood clots with a sterile phosphate-buffered saline solution containing penicillin, 50 µg/mL; streptomycin, 50 µg/mL; neomycin, 100 µg/mL; and amphotericin B, 2.5 µg/mL (Life Technologies Inc. Gaithersburg, MD). The amnion was separated from the rest of the Chorion by blunt dissection and flattened onto a nitrocellulose paper (Bio-Rad Inc. Gainesville, FL), with the epithelium–basement membrane surface facing away from the paper. The paper with the adherent amniotic membrane was then pulverized and ultramicronized and stored before transplantation at −80°C in a sterile vial containing Dulbecco-modified Eagle medium (Life Technologies Inc.) and glycerol (Baxter Health care Corp, Stone Mountain, Ga.

RESULTSThere were 32 men, with a mean (±SD) age of 46.5 ± 13.3 years. All Feet (n=32) were diagnosed as having Tendinopathy, tendinosis enthesitis by impression from radiographic and MRI examination that showed calcific enthesopathy on the involved retrocalcaneal enthesis region of the Calcaneus. Fourteen (54%) feet had had persistent or recurrent pain and induration with localized ankle inflammation (Table 1). Four feet, patient 14, had recurrent pain and deficiency of gait after prior injection, required a second AmnioFix injection after 8 weeks from initial treatment. For the mean (±SD) follow-up period of 3.5± .9 months, 22 (84%) of 26 feet showed visible improvement (excluding patient 9, who had preexisting traumatic tear). They consisted of 13 feet (≥6 pain from tendinosis), 6 feet (4-5 pain with calcific insertional enthesopathy), and 6 feet (1-3 enthesopathy and tendinopathy with rigid hind foot based on the Coleman block test scale). Four (15%) feet had minimal to no change in calcific insertional enthesopathy, including 1 tendinopathy with preexisting Tendoachilles avulsion trauma. Two (7%) feet lost 1 scale of function because of progressive weakness and the other 1 because of persistent painful enthesitis and tendinopathy with gait deficiency. Of the 32 feet, 29 (91%) feet had operative criteria. Among them, 16 of 26 patients (62%, excluding patient 9) regained painless gait function of better than 4 (scale of 5). Except for the 2 feet of patient 16, who had an atopic reaction to the transplanted amniotic membrane injection 24 hours after procedure, all other amniotic membrane injections showed complete improvement within 3 to 4 weeks, with reduced inflammation and pain with ambulation. In 3 (12%) of 26 feet receiving injection for tendinosis with tendinopathy, all feet were from patients within the surgical category, and 2 of them had received prior conservative treatment by other medical practitioner without success. These 6 patients were excluded from the favorable outcome tally.

Our study provides strong evidence that injection of micronized amniotic membrane alone can further enhance the success of treatment with nonsurgical methods for Tendoachilles calcific insertional enthesitis and tendinosis with tendinopathy. More research is needed to explore the regulation of tenocyte stem cells. Tendon cells, or tenocytes, are elongated fibroblast type cells. The cytoplasm is stretched between the collagen fibers of the tendon. They have a central cell nucleus with a prominent nucleolus. Tendon cells have a well-developed rough endoplasmic reticulum and they are responsible for synthesis and turnover of tendon fibers and ground substance. Tendon cells form a connecting epithelial layer between the muscle. Muscle cells are attached to the collagenous myotendinous space via hemidesmosomes. The myotendon space is then attached to the base of the tendon cells via basal hemidesmosomes, while apical hemidesmosomes, which sit atop microvilli, attach the tendon cells to a thin layer of collagen. This is in turn attached to organic fibers which insert into bone. Tendon cells appear columnar and contain a large basal cell nucleus. The cytoplasm is filled with granular endoplasmic reticulum and sparse golgi. Dense bundles of microfilaments run the length of the cell connecting the basal to the apical hemidesmosomes. The study of the mechanism of action with amniotic membrane matrix upon tendon regenerative physiology will inevitably unveil useful information for enhancing the outcome success of alternative treatments for this limiting ailment currently the “Achilles Heel” of human anatomy.