Stephen M. Herrington

Dislocation after total hip arthroplasty using the anterolateral abductor split approach.

The three basic surgical approaches used most commonly in total hip arthroplasty are transtrochanteric, posterior, and anterolateral. Complications related to each of these surgical approaches have been reported including dislocation, trochanteric nonunion, heterotopic ossification, neurovascular damage, postoperative limp, and implant malalignment. The anterolateral abductor split approach previously has been reported to allow ease of access into the hip joint, optimum joint visualization, protection of neurovascular structures of the hip, and predictable results for postoperative hip function restoration. Reviewing a large consecutive series of primary total hip arthroplasty cases (1518), the authors report an overall dislocation rate less than 1% (12:1518; 0.79%). Stratified by preoperative diagnosis, patients undergoing total hip arthroplasty after trauma, or presenting with congenital dysplastic hip are at the highest risk for postoperative dislocation. Primary total hip arthroplasty using the anterolateral, abductor split approach can minimize the rate of postoperative dislocation in the prevailing preoperative diagnostic categories.

Freehand resection of the patella in total knee arthroplasty referencing the attachments of the quadriceps tendon and patellar tendon

A freehand technique of patellar resurfacing using anatomic references was prospectively evaluated. This technique utilizes an osteotomy beginning at the inferior pole of the patella just posterior to the insertion of the patellar tendon and is carried proximally posterior to the insertion of the quadriceps tendon. Evaluation of 55 total knee arthroplasties in 41 patients showed an average restored patellar thickness within 0.1 mm. The overall patellar thickness was restored to within 1 mm of its preoperative thickness in 50 (91%) of 55 knees. Patellar tilt was equal to or less than 4 degrees in 42 (89%) of 47 arthroplasties evaluated radiographically. The patellar thickness averaged 17.9 mm, well above the critical value of 15 mm reported in the literature.

Particulate debris presenting as radiographic dense masses following total knee arthroplasty.

Two cases of failed total knee arthroplasty associated with significant titanium debris that created massive radiographic densities are reported. The similarities of the failed total knee arthroplasties are that both involve titanium femoral components with failed metal-backed patellar components. At the time of surgical intervention, patellar polyethylene dissociation from metal-backed patellar components was noted with excessive burnishing and wear of the remaining metal-backed patellar component and of the titanium femoral component. Wear of the tibial polyethylene was noted in both cases. The titanium-on-titanium wear couple produced significant debris, resulting in large mass formation about the total knee arthroplasty. Additionally, there were loculated, fluid-filled sacks of titanium debris. Histologic sections performed for both cases revealed significant deposits of titanium in combination with polyethylene. In both cases, radiographs revealed the presence of large, radiodense masses. These cases illustrate that when considering etiologies for radiodense masses about total joint arthroplasty, particulate titanium debris resulting in mass formation must be added to the differential diagnosis.

Revision of Loose Patellar Components

The issues, approach, and technique regarding patellar revision have been presented. Even though patellar complications are a definite clinical problem, many factors causing patellofemoral complications have been determined, which should aid in their reduction. When revising the patellar component, one must be diligent in preoperative planning in order to adequately determine the etiology of the patellofemoral complication. The factors responsible for the specific patellofemoral complication can then be adequately addressed.