Thru purpose of this study was to evaluate the clinical outcomes of a consecutive series of conversion total hip arthroplasty (cTHA) following previous hip fractures.

A retrospective chart review of patients who underwent cTHAs from 2008–2017 at an urban academic teaching institution was performed.

Eighty-eight patients were included in this study. The mean age at the cTHA was 66 years (range 27 to 89). 67% of the patients wre women. The mean BMI was 28 kg/m² (range 17 to 41). The mean Charlson Comorbidity Index was 3 (range 0 to 9). The mean follow-up was 49 months (range 24 to 131). The mean duration from the hip fracture fixation to the cTHA was 51 months (range 10 to 144). The mean operating time was 188 minutes, (range 71 to 423) with a mean estimated blood loss of 780 ml (range 300 to 2500). Revision-type (long-stem) designs were used in 65% of the cases. The mean length of hospital stay was 8 days (range 2 to 61). The readmission rate was 37% within 90 days after the CTHAs. Of these, 57% were due to non-orthopaedic complications. There were 10 orthopaedic complications: 7 PJIs, all of which required I&D and 3 required staged revision. There were 2 dislocations treated with closed reduction and 1 case of intraoperative periprosthetic femur fracture during femoral component insertion. There was no revision for aseptic loosening within the follow-up period. The one-year mortality rate was 0%.

cTHAs were associated with longer operating time, more blood loss, longer length of hospital stay, and higher readmission rates than the primary THAs in our institutional database. We believe utilizing a multi-disciplinary care protocol to optimize these patients is needed to reduce the high rate of readmissions, and the complications in this patient population.

Modular tapered stems have become increasingly popular in femoral revisions and stem subsidence remains a reported clinical problem. Computer modeling and biomechanical testing demonstrated a minimum initial line-to-line fit of 25 mm was required to reduce the risk of subsidence. We examined XR imaging of 110 consecutive femoral revisions by a single surgeon using two different modular tapered stems to determine if this biomechanical threshold was of clinical relevance. 72% of the revisions were done for aseptic loosening and 28% for periprosthetic fracture or infection. Stem subsidence of any degree was observed in 24 (21.8%), while 12 (10.9%) demonstrated substantial subsidence of > 10 mm. We matched this cohort to 12 patients who had no stem subsidence. The average age of patients with subsidence was 59 years (43 to 79 years). The average of patients without subsidence was 66 years (41 to 77 years). Each group had 7 men and 5 women. Stem subsidence was observed in the first 3 months post-surgery. The demographics, bone deficiency, stem design, and stem diameter were similar between groups.

83% of patients with substantial stem subsidence had less than 25 mm of line-to-line fit compared to 17% of patients without subsidence. The 12 cases of no stem subsidence had a mean line-to-line fit of 48 mm (25 to 55 mm). 75% of patients with substantial stem subsidence had also undergone an extended trochanteric osteotomy (ETO) compared to 33% of patients without subsidence.

We conclude that there is a positive correlation with the biomechanical testing parameters and substantial stem subsidence. ETO was found to be associated with higher stem subsidence.

The purpose of this study was to review the clinical and radiographic outcome in THRs done following acetabular fractures (fx). All patients undergoing conversion THR after previous acetabular fx between 1990 and 2006 at a single institution were identified.

Clinical evaluation was done using the Harris hip scale. Radiographic evaluation was done using the system proposed by the Hip society. THRs as part of initial treatment for acute acetabular fx were excluded.

There were 90 THRs (90 patients) performed in patients previously treated for an acetabular fracture. At the time of their acetabular facture, 67 had been treated with ORIF, 12 were treated with closed or limited open reduction and percutaneous fixation, and 11 were treated without surgery. The mean age at injury was 43.7 years, (range, 14–79). 68 patients sustained their fx from a high-energy mechanism (MVC, MPC, or MCC).

Three patterns accounted for 52% of the fx: transverse posterior wall (20), both column (18), and T-Type (9). Associated pelvic fractures were present in 14 patients. Associated ipsilateral proximal femur fractures were present: femoral head (four), femoral neck (five), and femoral shaft (three). Among those treated with ORIF, marginal impaction was noted in 31 and osteo-chondral head damage in 32 hips.

The mean interval between injury and THR was 42 months (range, two months to 32 years). Cement-less fixation was used in 81 of the 90 cups. Similarly, cementless stems were used in 80 stems. Bone graft was necessary in 26 patients (17 autograft, nine allograft). Two cases each required pelvic augments and reinforcement cage, respectively.

Additional findings at THR included: femoral head erosion (53 hips), femoral head osteonecrosis (37 hips), osteonecrosis of the acetabulum (22 hips), and fx non-union (six hips). The average cup abduction angle was 440 (range, 28 to 60), the average cup height was 24 mm (range, 10 to 42), and the average medialization distance was 23 mm (range, 5 to 48). The mean EBL was 810 ml and mean operative time was 195 minutes. The mean F/U was 36 months (range, 6 months to 17 years). The median Harris hip score was 89 at the most recent F/U. Fifteen revisions (16%) have been done: aseptic loosening (seven hips), recurrent dislocation (six hips) and infection (two hips).

Five of the six revisions for recurrent dislocation were performed in patients who had a posterior approach for both their acetabular fracture treatment and their THR. No revision was done in those who had been initially with percutaneous fixation. There was no infection in those who had been initially with percutaneous fixation either from the fx treatment or the THR. In contrast, 14 ORIF patients were complicated by infection. One of these developed infection following THR.

Our data support the clinical efficacy and mid-term durability of THR in this patient group. Aseptic loosening and recurrent dislocation remain the primary reasons for revision surgery.