Safety and Efficacy of IM Injections of PLX-PAD for the Regeneration of Injured Gluteal Musculature After Total Hip Arthroplasty

One of the main problems when performing THA via the standard transgluteal approach is the necessary injury of the gluteus medius muscle. The consecutive decrease of contractile muscle substance and the substitution by scar tissue leads to functional deficits of the pelvic-stabilizing musculature with an insufficiency limp in a large number of patients. In the long run the lack of musculature leads to a decrease in bone substance at the insertion sites of the gluteal muscles of the proximal femur. The present study has the aim of establishing a new therapy for iatrogenic gluteal muscle damage. The hypothesis of the present proposal is that intra-muscular (IM) injection of PLX-PAD into the iatrogenically injured gluteus medius muscle after THA results in an improved regeneration of the skeletal muscle tissue and consecutively in an improved functional outcome.

Subjects will be assigned to receive one of the two targeted doses of PLX-PAD or placebo. On the treatment day, after suturing the gluteus medius muscle PLX-PAD or placebo will be applied directly to the site of laceration.

Patients will be followed up for efficacy assessment up to week 26 and for safety assessment (Adverse events, vital signs, ECG, routinf lab and immunological testing) up to week 52 after THA. Patients will be phoned at week 104 in order to inquire about the occurence of new cancer.

Inclusion criteria

• Male or female subjects between 50 to 75 years of age
• Scheduled THA
• ASA Score ≤ 3
• Signed written informed consent

Exclusion criteria

• Muscle diseases
• Severe neurological diseases
• Opioid long term medication
• Pain chronification > stadium II of Gerbershagen
• Immunosuppression due to illness or medication
• Ankylosing spondylitis
• History of ectopic bone formation of any localisation
• Exclusion criteria for MRI (pace maker, defibrillator, ferromagnetic intracerebral clips)
• Uncontrolled hypertension (defined as diastolic blood pressure > 100 mmHg or systolic blood pressure > 200 mmHg during screening)
• Life-threatening ventricular arrhythmia or unstable angina - characterized by increasingly frequent episodes with modest exertion or at rest, worsening severity, and prolonged
• ST segment elevation myocardial infarction and/or TIA/CVA within three (3) months prior to enrollment. Subjects with severe congestive heart failure symptoms (i.e. NYHA Stage IV)
• Subject has malignancy undergoing treatment including chemotherapy, radiotherapy or immunotherapy
• Body Mass Index (BMI) of 35 Kg/m2 or greater
• Known allergies to protein products (horse or bovine serum, or porcine trypsin) used in the cell production process
• Known HIV, syphilis at time of screening
• Known active Hepatitis B, or Hepatitis C infection at the time of screening
• Pregnant or breast-feeding women or women of childbearing potential not protected by an effective contraceptive method of birth control (defined as pearl index < 1)
• In the opinion of the investigator, the subject is unsuitable for cellular therapy
• Subject is currently enrolled in, or has not yet completed a period of at least 30 days since ending other investigational device or drug trial(s)
• Subjects who are legally detained in an official institute