Autologous Tenocyte Injection for the Treatment of Chronic Recalcitrant Gluteal Tendinopathy: A Prospective Pilot Study.
BACKGROUND
Gluteal tendinopathy is a common cause of lateral hip pain, and existing conservative treatment modalities demonstrate high symptom recurrence rates. Autologous tenocyte injection (ATI) is a promising cell therapy that may be useful for the treatment of gluteal tendinopathy.


OBJECTIVE
To investigate the safety and effectiveness of ATI, specifically in patients with chronic recalcitrant gluteal tendinopathy.


METHODS
Case series; Level of evidence, 4.


METHODS
Twelve female patients with a clinical and radiological diagnosis of gluteal tendinopathy were recruited. Patients demonstrated a mean duration of symptoms of 33 months (range, 6-144 months), had undergone a mean 3.2 prior corticosteroid injections (range, 2-5), and had failed to respond to existing conservative treatments including physiotherapy and injections. In an initial procedure, tendon cells were harvested from a needle biopsy of the patella tendon and propagated in a certified Good Manufacturing Practice (GMP) laboratory. In a secondary procedure, a single injection of 2 mL autologous tenocytes (2-5 × 106cells/mL) suspended in patient serum was injected into the site of the pathological gluteal tendons under ultrasound guidance. Patients were assessed pre- and postinjection (3, 6, 12, and 24 months) using the Oxford Hip Score (OHS), a visual analog pain scale (VAS), the Short Form-36 (SF-36), and a satisfaction scale. Magnetic resonance imaging (MRI) was undertaken at 8.7 months (range, 6-12 months) postinjection.


RESULTS
Molecular characterization of autologous tendon cells showed a profile of growth factor production in all cases, including platelet-derived growth factor α, fibroblast growth factor β, and transforming growth factor β. The OHS (mean, 24.0 preinjection to 38.9 at 12 months [14.9-point improvement]; 95% CI, 10.6-19.2;P< .001), VAS (mean, 7.2 preinjection to 3.1 at 12 months [4.1-point improvement]; 95% CI, 2.6-5.6;P< .001), and SF-36 (mean, 28.1 preinjection to 43.3 at 12 months [15.2-point improvement]; 95% CI, 9.8-20.5;P< .001) significantly improved to 12 months postinjection, sustained to 24 months. Eight patients were satisfied with their outcomes. Significant MRI-based improvement could not be demonstrated in the majority of cases.


CONCLUSIONS
ATI for gluteal tendinopathy is safe, with improved and sustained clinical outcomes to 24 months.
Fremantle Hospital, Fremantle, Western Australia, Australia.; Perth Orthopaedic and Sports Medicine Centre, West Perth, Western Australia, Australia.
Thomas A
TA
Bucher
School of Human Sciences, University of Western Australia, Crawley, Perth, Western Australia, Australia.
Jay R
JR
Ebert
The School of Physiotherapy and Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia.
Anne
A
Smith
Perth Radiological Clinic, Subiaco, Perth, Western Australia, Australia.
William
W
Breidahl
Perth Radiological Clinic, Subiaco, Perth, Western Australia, Australia.
Michael
M
Fallon
School of Surgery (Orthopaedics), University of Western Australia, Crawley, Perth, Western Australia, Australia.
Tao
T
Wang
School of Surgery (Orthopaedics), University of Western Australia, Crawley, Perth, Western Australia, Australia.
Ming-Hao
MH
Zheng
Perth Orthopaedic and Sports Medicine Centre, West Perth, Western Australia, Australia.
Gregory C
GC
Janes
autologous tenocyte implantation; cellular therapy; clinical outcomes; gluteal tendinopathy; greater trochanteric pain syndrome