Intermediate clinical follow-up of a dual-radius acetabular component.

In this study, 92 primary total hip arthroplasties were performed in 83 patients using a porous-coated, dual-radius, cementless, acetabular component. All hips underwent line-to-line dome reaming with press-fit implantation that was judged to have complete bone contact. This acetabular shell provides a 1-mm oversized peripheral rim, which adds excellent initial stability while allowing complete bone contact in all hips. No fractures occurred. In 83% of hips, adjunctive screw fixation was not necessary. At a minimum of 4 years, follow-up, there were no revisions, no acetabular migration, one case of acetabular erosion consistent with osteolysis, and the average Harris Hip Score was 95. The design features of this new acetabular component have provided excellent fixation with complete initial bone contact, resulting in satisfactory intermediate clinical and radiographic results. The design provides excellent peripheral stability and complete bone contact.

Removal and reinsertion of cemented femoral components during acetabular revision.

A retrospective review examined all patients who underwent removal and reinsertion of a cemented femoral component during isolated acetabular revision by one surgeon since 1981. All components were reinserted into the original, intact cement mantle. Forty-two hips with 2- to 10-year follow-up periods were reviewed. Average follow-up period since revision was 67 months. Average followup period since index procedure was 191 months. Average Harris hip score increased from 61 before surgery to 90 at follow-up examination. Two femurs are definitely loose by Harris criteria, but both are asymptomatic. One solidly fixed femoral component was revised because of joint instability. Two hips have postrevision cement fractures. One patient has mild thigh pain. In vitro testing of eight cadaver hips showed no increase in rotational micromotion following removal and reinsertion. It is concluded that this technique aids in isolated acetabular revision surgery by avoiding the complications of trochanteric osteotomy and femoral revision, improving acetabular exposure, and decreasing operative time with minimal risk of disrupting femoral component fixation.

Wear debris from bipolar femoral neck-cup impingement. A cause of femoral stem loosening.

The source of wear debris in total hip arthroplasty may occur at various interfaces: metal-ultra-high molecular-weight polyethylene bearings, metal-cement micromotion, bone-cement interfaces, and implant coatings. Wear-induced osteolysis may result in a spectrum of radiographic changes from radiolucent lines to massive osteolysis. Subsequent loosening of the implant may occur and revision may be difficult because of bone deficiencies. Impingement of the femoral neck on the acetabular component may result in polyethylene and/or metal debris, leading to early femoral stem loosening. The five cases presented, involving six hips, illustrate how bipolar cup-stem impingement may result in significant wear-induced femoral osteolysis.

Femoral revision total hip arthroplasty using a long-stem femoral component. Clinical and radiographic analysis.

Proximal femoral bone stock deficiencies exist during many femoral revision arthroplasties, thus providing inadequate support and fixation for conventional-length cemented femoral components. The authors analyzed the long-term clinical and roentgenographic results of 165 hips requiring femoral revision arthroplasty with a long-stem femoral prosthesis. Intraoperative complications occurred in 23% of hips, with femoral perforations in 16% and femoral fractures in 5%. Of 110 hips with at least 5 years of follow-up study (average, 6.7 years), functional ratings were graded excellent in 34%, good in 36%, fair in 17%, and poor in 13%. Failures occurred in 17 hips (12%) and were attributed to aseptic loosening (11 hips), femoral component fracture (2), femoral shaft fracture (1), and sepsis (3). Symptomatic trochanteric separations occurred in 16% of hips. Rerevision or resection arthroplasty was required in 7 hips (5%) and recommended for another 10 hips (7%). Cemented long-stem femoral components (versus cemented conventional-length stems) decrease the extent and progression of femoral lucencies, thereby lowering the incidence of mechanical failures and improving long-term functional results in cemented femoral revision arthroplasty.

Aseptic loosening in metal-backed acetabular components for total hip replacement. A minimum five-year follow-up.

We reviewed the cases of thirty-six patients who had forty cemented total hip replacements with the Harris metal-backed acetabular component. The operations were done between 1972 and 1977, and the duration of follow-up averaged 7.6 years (range, five to 10.8 years). The average age of the patients was forty-four years (range, sixteen to sixty-two years). Aseptic loosening of the acetabular component occurred in three hips (7.5 per cent), and three more sockets were revised for other reasons. Two of the three sockets with aseptic loosening were in the fifteen patients (seventeen hips) who were forty-five years old or younger. The remaining loose cup was in one of the twenty-one patients (twenty-three hips) who were forty-six years old or older. The reduction in the rate of aseptic loosening of the socket in our series, compared with the higher rates reported in similar long-term studies in which other acetabular components were used, supports the conclusion that there is enhanced longevity of acetabular fixation when a metal-backed acetabular component is used in cemented total hip arthroplasty.

Intramedullary fixation of humeral shaft fractures.

In this paper we document seventy fractures of the humeral shaft that were treated by intramedullary fixation between 1970 and 1981. Complications developed in forty-seven (67 per cent) of the fractures, and forty-five (64 per cent) required at least one additional operative procedure. Of the sixty fractures that were internally fixed within six weeks after injury, nine (15 per cent) had a delayed union and five (8.3 per cent) had a non-union, two of which persisted despite subsequent surgery. Three of the ten fractures that were internally fixed more than six weeks after injury never united despite additional procedures that were done to secure union. Delayed union and non-union were more common in open fractures (33 per cent) than in closed fractures (21 per cent), and with open reduction (39 per cent) than with closed or so-called semi-open reduction (9 per cent). Deep infection occurred in three (5 per cent) of the fractures and was more common in open (17 per cent) than in closed fractures (2 per cent). One of the three open fractures that were treated by immediate fixation became infected, as compared with only one of the nine open fractures treated by delayed fixation. Painful adhesive capsulitis of the shoulder developed in thirty-four (56 per cent) of the patients who had fractures treated with distally directed pins, but motion of the elbow was not restricted in the nine patients with fractures treated with proximally directed pins.

Bilateral subtalar dislocations. A case report.

A 29-year-old man with bilateral subtalar dislocations demonstrated that neurologic damage can accompany subtalar dislocation. Neurologic injury, among other well known risk factors, produces poor final results. Serial 99mTc bone scans with a pin-hole collimator are useful for evaluating the vascularity of the talar body.