To evaluate the clinical efficacy of uncemented total hip arthroplasty (THA) in the treatment of end-stage hip disease in young patients under 25 years old.

Patients who were under 25 years of age and received uncemented THA in the Department of Orthopedics of the 940th Hospital of Joint Logistic Support Force of PLA from January 2009 to December 2018 were retrospectively analysed. The exclusion criteria were the patients who were treated with THA for hip tumour or hip infection, less than three years of follow-up, lost in follow-up or with incomplete data. The demographic data of patients were routinely collected and combinations of clinical scores and imaging assessments were used to assess outcomes of the surgery. Following clinical assessment were compared before surgery and at last follow-up after surgery: Harris hip score, Western Ontario & McMaster Universities osteoarthritis index (WOMAC) and Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Paired sample t test was used for clinical scores. Independent sample t test was used to compare the scores between different liners. Postoperative complications such as infection, revision, dislocation, incisional healing complications, etc. were recorded. Imaging assessment included: pelvic anteroposterior and hip anteroposterior and lateral X-rays for assessment of the position of prosthesis, prosthesis loosening and wear, osteolysis, heterotopic ossification and femoral filling rate. Loosening of acetabular or femoral component or a revision for any reason was defined as failure.

A total of 20 patients (27 hips) with a mean age of (21.8±2.3) years were included. There were 16 males (23 hips) and four females (four hips) for 13 left-sided (48.1%) and 14 right-sided (51.9%) uncemented THA. Seven patients underwent bilateral THA and 13 had unilateral THA. Of all patients, the average body mass index (BMI) was (21.3±3.2) kg/m² and the mean follow-up time was (7.8±2.4) years. During follow-up, one patient had a replacement of prosthetic liner due to infection, and the rest of patients had no THA related complication. Harris score, WOMAC score, the physical component score-SF-36 and the mental component score-SF-36 were significantly improved at the last follow-up compared with the scores before surgery (t=-25.31, 19.47, -10.18, -7.26, all P<0.05). Imaging examinations at the last follow-up showed no significant change in position of prostheses compared with the images right after the surgery, and the range of prosthetic valgus angle was 32° to 58°, at (43±7)° on average. The prosthetic anteversion angle ranged 9° to 26°, on (18±4)° on average. No loosening, wearing, osteolysis or heterotopic ossification occurred. At the final follow-up, an overall survival rate of 96.3% was achieved for the 27 hips.

For the patient who are under 25 years of age and with an end-stage hip disease, the uncemented THA can better restore hip functions with a high survival rate, few complication and satisfactory clinical efficacy.