OKOJ, Volume 11, No. 3

The pelvis is a flexible, dynamic stabilizer between the lower lumbar spine and the hip joints. Depending on the body posture or specific disease or deformity affecting the spine or lower limbs, the pelvis will compensate in the coronal and sagittal planes to maintain balance and minimize energy expenditure. If such rotational adaptations of the pelvis are not considered during total hip arthroplasty, the result may be malalignment of the acetabular component, functional instability, and a perceived limb-length discrepancy postoperatively. Moreover, improper orientation of the acetabular cup can have even more severe consequences if metal-on-metal bearing surfaces are used due to the potential for metallic wear debris. The final position of the acetabular cup in total hip arthroplasty must not only be appropriately oriented in three dimensions, but also dynamic and functional for optimal outcome. This chapter discusses the dynamic relationship between the pelvis and the spine and its application in total hip joint replacement.

Disorders of the tendons about the foot and ankle represent both a diagnostic and a therapeutic challenge to the orthopaedic surgeon. Most of these disorders can be attributed to overuse, but intrinsic and extrinsic factors also play a role. A thorough knowledge of the anatomy and biomechanics of the foot and ankle, as well as good clinical judgment and expertise in treating these disorders, are essential for successful management. This article reviews current strategies for diagnosis and treatment of common diseases and injuries of the peroneal, flexor hallucis longus, and tibialis anterior tendons.

Osteochondritis dissecans (OCD) is a disease of subchondral bone that leads to a spectrum of pathologies, ranging from the softening of articular cartilage to the complete detachment of an osteochondral fragment, creating an intra-articular loose body. In the past 4 years, important findings have altered the management of OCD. Nonsurgical management is the preferred initial treatment for OCD. Two surgical techniques for stable lesions are transarticular antegrade and extra-articular retrograde drilling. However, although both techniques may lead to good outcomes, AAOS clinical practice guidelines do not firmly recommend either technique. Unstable lesions are often treated with arthroscopic reduction and internal fixation, microfracture, or osteochondral autologous transplantation. The internal fixation of unstable OCD lesions with a headless screw has shown good results, and in a paper published in 2010, was reported to produce excellent results with a bioabsorbable implant. A prospective, randomized trial reported in 2009, in which microfracture was compared with osteochondral autologous transplantation, found that patients who underwent osteochondral grafting had significantly better outcomes at 4 years postoperatively.