We compared the first 380 patients receiving THAs using a cemented polyethylene (PE) acetabular liner and cemented femoral stem (Ceraver, France) at our institution between 1995 and the end of 1999 with 412 patients who underwent hemiarthroplasties (bipolar or hemipolar hemiarthroplasty) before this date (1990–1994). From 1995 to 1999, we also treated 42 patients with hemiarthroplasties, and from 1990 to 1999, 123 patients underwent internal fixation or other methods. The indication for internal fixation was age younger than 65 years. The indications for THA were: (1) patients older than 65 years, (2) active patient, and (3) independent at home. The indications for hemiarthroplasty were: (1) patients older than 65 years, (2) nonactive patient, (3) nonindependent at home, and (4) patients who were cognitively or neurologically impaired. The contraindications for surgery (26 patients from 1990 to 1999) were: (1) nonambulatory patients, and (2) patients with contraindication to anesthesia. No patients were recalled specifically for this study; all data were obtained from medical records and radiographs.
In the hemiarthroplasty group (412 patients), 201 patients were men and 211 were women, with an average age of 80 years (range, 65–92 years) and a diagnosis of neck fracture. All patients received a cemented arthroplasty (280 bipolar, 132 unipolar hemiarthroplasties), performed between 1990 and 1994 at the same hospital. The 90-day mortality for patients undergoing hemiarthroplasty for hip fracture was 2.6%. Forty patients died before their 5-year followup and eight had revision surgeries for infection. Additionally, 63 of the 412 patients were lost to followup after 5 years. This left 309 of the 412 patients (75%) with a followup of 5 years, 201 (49%) with a followup of 10 years, 87 (21%) with 15 years, and 32 (8%) with 20 years. We examined their records at their most recent followup or before their death. The average followup, as reported in medical records, was 9 years (range, 1–20 years). Surgeons performed surgery using a posterolateral approach and general anesthesia. The stems were always the same (Ceraver Osteal, Roissy, France), made of anodized titanium alloy (TiAl6V4), smooth, and always cemented. Surgeons fixed femoral components with cement (Palacos® G; Heraeus Medical GmbH, Hanau, Germany) containing antibiotics (gentamicin).
The THA group consisted of 380 patients (175 men, 205 women), with an average age of 79 years (range, 64–90 years). Between 1995 and 1999, all patients received a cemented THA at the same hospital. The 90-day mortality in these patients undergoing THA for hip fracture was 2.8%. Thirty patients died before their 5-year followup. Nine patients had revision surgeries for infection, and 51 of the 380 patients were lost to followup after 5 years. This left 299 of the 380 patients (79%) with a minimum followup of 5 years, 191 (50%) with a followup of 10 years, and 98 (26%) with 15 years. The average followup (as reported in medical records) was 7 years (range, 1–15 years). Surgeons performed this surgery using the same technique, general anesthesia, and stems (also cemented) as used in the hemiarthroplasty group. The conventional acetabular component was a standard PE cup manufactured by Ceraver (all cemented). The alumina head was 32 mm in diameter and anchored through a Morse taper.
Age and gender proportions were similar in the two groups (mean age of 80 years in the hemiarthroplasty group versus 79 years in the THA group).
For postoperative rehabilitation, no patient wore a hip spica cast to minimize the possibility of hip dislocation. We encouraged patients to be upright with weightbearing after surgery. Range of motion of the hip and knees began immediately, and ambulation progressed as tolerated according to the ability of each patient (usually after 48 hours). Medical doctors supervised the physiotherapy for 3 weeks to 45 days.
The followups were at 3, 6, and 12 months, then annually thereafter. At each visit, patients had clinical and radiologic evaluations. The usual hip-rating scores do not reflect the function of THA well in patients with hip fractures because the age or medical status may affect the functional variables. The preoperative and postoperative walking status of patients was graded as unable to walk, able to walk indoors only, able to walk about the community, and able to walk an unlimited distance. All patients, except the eight with hip infections, subjectively showed improved ambulation (they were able to walk about the community or able to walk an unlimited distance) after surgery. Every year until the most recent followup, plain radiographs (AP and lateral views) were obtained. From the charts, we determined whether there were any dislocations (posterior or anterior) or revisions for recurrent dislocation, loosening, or wear of cartilage for hemiarthroplasties. We routinely evaluated patients, in person or via a standardized letter or telephone questionnaire, at 2 to 3 months postoperatively, at 1, 2, and 5 years, and then at each subsequent 5-year interval until revision or death. At each time, we specifically asked patients whether they had experienced dislocation of the hip. We did not consider a sensation of subluxation of the hip to be sufficiently specific to represent an episode of hip instability, and only considered a complete hip dislocation requiring reduction to be a dislocation event.
Three of us (PH, MB, OP) evaluated all immediate postoperative radiographs and all radiographs at last followup to assess wear of the cartilage for hemiarthroplasties, and loosening of the cup for THA. We defined loosening of the socket as cup migration exceeding 5 mm, angular rotation exceeding 5º, and a continuous radiolucent line wider than 2 mm [6
]. To assess cartilage wear we used the criteria of Baker et al. [2
]. Cup position was assessed according to the acetabular position angle [22
We expressed qualitative data (ie, gender) as counts and percentages within groups and quantitative data by mean standard deviation or range. We compared these qualitative data between the two groups using the Chi square test or Fisher’s exact test. To estimate the cumulative probability of not having a dislocation in the whole series, we used the Kaplan-Meier survivorship analysis [13
], with 95% confidence intervals (to deal with missing data). Differences in survival were determined using the log-rank test. We estimated the cumulative risk of dislocation as reported by Berry et al. [3
] using the Kaplan-Meier method [13
], and performed Kaplan-Meier survivorship analysis with revision attributable to recurrent dislocation, wear of cartilage, and acetabular protrusion for hemiarthroplasty, or loosening for THA as the endpoint.