Understanding the Pathoanatomy of Arthritic Hip for Improvising the Technique in Primary Uncemented Total Hip Arthroplasty

Background: Hip osteoarthritis is a condition that leads to significant morbidity and decreases the quality of patient’s life. Total Hip Arthroplasty (THA) is preferred by most of orthopaedic surgeons to relieve pain, provide motion while maintaining stability. In this study we aim to discuss the difficulties encountered in reference to patho-anatomy during THA in various conditions along with their solutions.

Materials and Methods: In our study, we had observed 100 hip joints of secondary osteoarthritis in 67 patients of with different type of underlying pathology like avascular necrosis, sickle cell disease, rheumatoid arthritis, ankylosing spondylitis. All the patients were evaluated using modified harris hip score. The findings were evaluated using SPSS software (Ilionois, Chicago) with p value less than 0.05 considered as significant.

Observation and Results: We had operated 100 hip joints (n=100) having arthritic changes among 67 patients (33 patients with bilateral hip affection, 34 patients with unilateral hip affection) at our tertiary care hospital from June 2015 till December 2019. The mean Harris Hip Score at the final follow up was 88 among them 98 hip joints had excellent and 2 hip joints had good to fair results. During our study we majorly encountered three types of collapse – Anterosuperior collapse (56%), Concentric collapse (25%) and hip arthritis due to inflammatory conditions (19%). We had found that according to duration and types of collapse different soft tissues were contracted and a step-wise release of those structures is necessary for proper intra-operation reduction and post-operative better range of motion. The steps for global release as and when required in different patients include adductor tenotomy, release of external rotator muscles, release of anterior fibers of gluteus medius, release of tensor fascia lata and tendinous insertion of gluteus maximus along with release of posterior capsule, release of anterior capsule followed by release of iliopsoas tendinous insertion on lesser trochanter.

Conclusion: The chronicity of the disease will lead to anatomical changes of the surrounding soft tissue and that will affect the surgical dissection. We had described surgical problems encountered during the operation and their solutions for each type of pathoanatomy. This will help orthopedic surgeons to anticipate and prepare well in advance while performing total hip arthroplasty.