Philip C. Noble

Hip arthroplasty after intramedullary hip screw fixation: a perioperative evaluation.

Objectives: Although literature exists regarding surgery after hip screw/side plate devices, we are unaware of any reports of hip arthroplasty after intramedullary devices. Design: This is a retrospectively reviewed case series. Setting: Tertiary care medical center. Patients/Participants: A consecutive unselected series. Intervention: Hip arthroplasty surgery after failed hip fracture fixation surgery using an intramedullary nail device. Main Outcome Measurements: Twenty cases of conversion surgery after intramedullary fixation for hip fractures were retrospectively reviewed. Results: The indications for hip arthroplasty were nonunion with failed fixation in 15, avascular necrosis with secondary hip arthritis in three, and progression of hip arthritis in four. Average operative time and blood loss were 166 minutes and 621 mL, respectively. Of note, nine of 20 patients ultimately developed a nonunion of the greater trochanter after hip arthroplasty. In only one of these cases of nonunion was the greater trochanter refractured intraoperatively and this as part of a trochanteric osteotomy. Conclusion: Patients undergoing hip arthroplasty after failed hip fracture fixation using an intramedullary nail device are at high risk for greater trochanteric fracture and nonunion. The average operative time and blood loss for these procedures were greater than reported for primary but less than for revision arthroplasty. We now consider treating these cases with a trochanteric plate with or without a trochanteric slide osteotomy to minimize fracture of the remaining, damaged trochanteric bone. Level of Evidence: Therapeutic Level IV. See page 128 for a complete description of levels of evidence.

Biomechanical Advances in Total Hip Replacement

Cemented hip arthroplasty is one of the most successful procedures of modern surgery. However, attempts to extend this procedure to younger and more active individuals using cemented or cementless methods of fixation have met with mixed success. Cementless procedures still have an unacceptable incidence of pain and limp at follow-up. These symptoms appear to be related to the presence of localized areas of instability of the stem/bone interface secondary to inadequate proximal or distal fixation. In addition, an alarming complication of some cementless prostheses is focal osteolysis which appears to arise from a foreign body reaction to particulate debris generated by motion between the implant and bone. Continuing advances in cementless arthroplasty will arise from a systematic approach to implant design leading to more anatomic stems, greater integration of implants and instruments, and increased attention to the impact of surgical technique on implant/bone fit and the stability of cementless fixation.

Survivorship and Clinical Results After Hip Arthroscopy: How Should We Define a Good Treatment Option?

While the arthroscopic approach has lower rates of complications with a faster recovery course, technique and pathology-related complications remain. Patient-reported and clinician measured outcome scores use survival of the native hip to quantify hip function and define a successful outcome from a hip procedure. Survivorship is dependent upon the severity and location of hip pathology at initial presentation, and the treatment selected, with the leading causes of persistent pain, dissatisfaction, and reoperation being untreated or inadequately treated pathology. The presence and severity of arthritis is a strong predictor of inferior clinical outcomes, with higher survivorship after arthroscopic treatment in cases with mild or no arthritis compared to moderate or advanced arthritis. Older patients also experience worse outcomes after arthroscopic surgical repair of labral tears and arthroscopic treatment of FAI; however, many authors have attributed this correlation in older patients to the presence of early osteoarthritis in older hips rather than age alone.

Research into the Application of Imaging to the Diagnosis of Hip Disease

The early detection of pathologic changes in articular cartilage has emerged as a key component of active research within musculoskeletal imaging of the hip joint. These efforts have focused on the identification of morphologic, physiologic, and molecular markers of cartilage damage. Imaging modalities that utilize these markers must balance the demands of rapid image acquisition, cost, invasiveness, reproducibility, sensitivity and specificity, while also being reliable, and responsive. Two modalities that have proven most promising for clinical application in assessing articular tissue are ultrasound and magnetic resonance imaging (MRI). While ultrasound provides information about the internal derangement of cartilaginous tissue, magnetic resonance imaging (MRI) detects changes in the composition of the tissue as reflected in its content of glycosaminoglycans (GAGs), collagen, and water. Currently, MRI is the best imaging modality for characterizing the articular cartilage of the hip and underlying subchondral bone because of good tissue contrast. Moreover, MRI surpasses surgical visualization in its ability to reveal the underlying femoral and acetabular anatomy. However, conventional MRI techniques are limited in their capacity to quantify defects within cartilaginous tissue, including the presence of fissures, fibrillation, and contained non-displaced delamination. Recent MRI techniques attempt to overcome these issues by better illustrating and characterizing hip hyaline cartilage ultrastructure via type II collagen and glycosaminoglycan content.

Functional Mechanics of the Human Hip

The application of scientific principles to the study of the hip has provided insight into morphologic and biomechanical factors compromising hip function, including acquired abnormalities (e.g., posttraumatic deformities, Perthes disease, slipped capital femoral epiphysis), developmental pathologies (e.g., developmental dysplasia of the hip [DDH]), and abnormalities of unknown origin (e.g., cam deformity of the femoral head-neck junction and pincer deformities of the acetabular margin).

Activities, Symptoms, and Expectations of Patients Undergoing Hip Surgery

Does hip surgery restore normal hip function? While it is generally accepted that surgery is performed to avoid, or overcome, pain and deterioration of function, the underlying pathologies of hip deformity and dysfunction differ. Three common surgical procedures—hip osteotomy, hip arthroscopy, and total hip replacement—treat hip pathologies at three very different stages of life.