The goal of this clinical trial is to see if people with knee osteoarthritis would be willing to comply and adhere to incorporating Recombinant Human Growth Hormone (rHGH), specifically Saizen Somatropin solution, into their treatment plan.

Participants will be asked to:

• Self-inject the treatment solution (placebo or somatropin) into the abdominal or gluteal area once per day for a total of 6 weeks.
• Complete questionnaires related to their knee pain and activities of daily living.
• Provide blood tests.
• Complete various measurements including: circumference of thigh, calf, and abdomen; strength of thigh and knee; range of motion of both knees; and gait analysis.

Inclusion Criteria:

• Between 18 - 65 years old.
• Diagnosis of isolated knee osteoarthritis for greater than 6 months.

Exclusion Criteria:

• Previous or pending major intra-articular or reconstructive surgery to the involved knee, including femoral/tibial osteotomies, ligament repair/reconstruction, or cartilage transplantation. Patients with remote (>1 year) diagnostic arthroscopy, arthroscopic debridement, meniscectomy, or meniscal repair may be allowed to participate at the investigators' discretion.
• Previous major trauma (including fracture, dislocation, open injury) to the involved knee, or ipsilateral hip, knee, ankle, or hip. Patients with prior complete ligament tears will be excluded, patients with chronic partial thickness ligament tears or degenerative/complex meniscal tears (>6 months from injury) may be included at the investigators' discretion
• Recent (less than 6 months) intra-articular injection into the involved knee.
• High grade ligamentous knee injury.
• Known allergy to recombinant human growth hormone (rHGH) or reconstitutive solutions.
• BMI of less than 20 or greater than 35.
• Documented history of growth disorder of bones or connective tissue, type 1 or 2 diabetes, myopathy, cancer, endocrine disorder, severe hypertension (SBP > 180) or rheumatologic disorder.
• Pregnant or breastfeeding, or actively attempting to get pregnant.
• Currently on hypoglycemic therapy, oral estrogen or glucocorticoid replacement therapy.
• Would have difficulty with the self-injection schedule or other cognitive/ functional limitations.
• Have taken creatine within 7 days before baseline. Potential participants will be given the option to pause their supplements and then re-screen if they are interested in the study,
• Have taken anabolic steroids within 42 days (6 weeks) before baseline. Potential participants will be given the option to pause their supplements and then rescreen if they are interested in the study,
• Vital signs or routine bloodwork outside of normal range.

Data Sharing Statement: All data relevant to the study will be included in the final study manuscript or uploaded as supplementary information.

Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures, and appendices).

Beginning 3 months and ending 5 years following article publication.

Researchers who provide a methodologically sound proposal will be able to access the IPD and supporting information to achieve aims in the approved proposal.

Proposals should be directed to david.wasserstein@sunnybrook.ca. To gain access, data requestors will need to sign a data access agreement.