Fifteen-year clinical survivorship of Harris-Galante total hip arthroplasty

Five-year results of metal-on-metal resurfacing arthroplasty in Asian patients

Clinical results of 50 metal-on-metal resurfacing arthroplasties in 45 Japanese patients were evaluated to a minimum follow-up of 5 years. The predominant diagnosis was developmental dysplasia or dislocation of the hip (70%). One patient died of an unrelated cause and another was lost to follow-up. Two hips received revision surgery, including 1 femoral neck fracture and 1 septic loosening. In the remaining 46 hips, 1 hip showed femoral component loosening. Clinical scores of the 46 hips were satisfactory at the final follow-up. The survival rate at 5 years was 96% when failure was attributed to revision for any reason. Metal-on-metal resurfacing arthroplasty in Japanese patients, who have a different distribution of hip diseases from European and American patients, showed similarly promising early clinical results.

Clinical impact of obesity on stability following revision total hip arthroplasty

Similar outcomes have been reported for obese and nonobese patients after primary total hip arthroplasty (THA), indicating obesity is not a contraindication to total hip arthroplasty. However, obese patients may develop implant failure and require revision THA. We compared the outcomes of revision THA in a matched cohort of obese and nonobese patients. Patients were stratified into two groups according to BMI (body mass index, kg/m2): Group 1 included 31 obese patients (BMI > 35), and Group 2 included 62 nonobese patients (BMI < 30) matched on age, gender, and type of revision procedure. Obese patients had increased total operating room time, a higher rate of discharge to a skilled nursing facility, and a higher dislocation rate (p < 0.05). Seven patients in the obese group underwent revision surgery, six of whom underwent additional reoperations to treat recurrent postoperative dislocation. Obese patients should be counseled about the increased risk of dislocation that can occur after revision THA.

Hydroxyapatite-coated femoral components: 15-year minimum followup

Hydroxyapatite-coated femoral components were introduced to enhance fixation, but concerns were raised about whether the coating would be maintained over time. We therefore determined the long-term clinical and radiographic results of a proximally hydroxyapatite-coated femoral component and compared the mechanical failure rate to other fixation methods at similar lengths of followup. The study group, culled from a large, multicenter prospective study population, consisted of 146 patients (166 hips) with followup of 15 to 18 years. Average age at time of the index procedure was 51 years, and the most common diagnoses were osteoarthritis (71%) and osteonecrosis (11%). Average Harris hip scores were 42.7 preoperatively and 91.5 at most recent followup. Radiographically, one stem showed stable fibrous fixation, and all other unrevised stems were bony stable. Of 13 stem revisions in the study population, only one stem has been revised for aseptic loosening. Forty-nine percent of hips have an osteolytic lesion in proximal areas of Gruen Zones 1, 7, 8, or 14 only. Both the femoral aseptic revision and mechanical failure rates are 0.6% at 15-year minimum followup. The data demonstrate excellent long-term survivorship of this hydroxyapatite-coated femoral component used in a relatively young patient group.

Porous-coated cups fixed with screws: a 12-year clinical and radiostereometric follow-up study of 50 hips

BACKGROUND

Excellent mid-term results have stimulated the use of hemispherical porous-coated cups in hip replacement. With longer follow-up, there have been problems related to polyethylene wear and liner fixation, and osteolysis has been documented in reports of selected cases. We evaluated the clinical and radiographic results of 50 patients followed for 12 years.

PATIENTS AND METHODS

58 consecutive patients (58 hips), mean age 55 years, were operated with Harris-Galante (HG) I or II cups using line-to-line fit and additional screw fixation. Polyethylene linersgamma-sterilized in air and 32-mm ceramic heads were used. 8 patients died within 12 years, leaving 50 patients with a complete 12 year follow-up. 23 of the cups were also evaluated with radiostereometry (RSA) for migration, liner stability, and wear.

RESULTS

All metal shells were still in situ after 12 years. 4 hips had been revised due to femoral loosening. In these revisions, the liner had been exchanged due to wear and/or instability, resulting in a cup survival rate of 89%. 28 cups displayed osteolytic lesions, mainly in relation to screws. RSA revealed minimum translations, but in many cases there were pronounced liner rotations suggesting unstable liners within the metal shell. The annual proximal wear was 0.09 mm and the three-dimensional wear was 0.16 mm.

INTERPRETATION

RSA can predict the long-term performance of cup fixation. Low migration during the initial years after implantation indicates excellent long-term results regarding fixation of the metal shell. The main problem with this design appears to be liner instability and osteolysis, factors that are probably interrelated. Because these phenomena are clinically silent, we recommend regular follow-up of patients with HG cups to avoid sudden loosening and complicated revisions.

Long-term results of the metal-cancellous cementless Lübeck total hip arthroplasty: a critical review at 12.8 years

INTRODUCTION

The influence of a spongy metal surface total hip arthroplasty (THA) (S&G, ESKA, Lübeck, Germany) on the clinical, psychometric, and radiograhic long-term results were examined.

MATERIAL AND METHODS

An amount of 137 THA with the cementless spongy metal Lübeck hip prosthesis were evaluated long-term, radiographically and clinically, with a mean follow-up time of 12.8 years (range 10.1-14.9 years). The MOS SF-36 was used to assess the health-related quality of life (HRQL).

RESULTS

Cumulative survival rates were 90% (+/-8%) for the cups and 86% (+/-5%) for the stems at 14.9 years. Four stems fractured at the middle part (3%) without major trauma. In the remaining patients the clinical results expressed as Harris Hip Score (HHS) averaged 88 (range 34-100). Patients above 60 years undergoing THA had no significant difference in HRQL (MOS SF-36) in comparison to the age-matched healthy population (P>0.05). Patients younger than 60 years had scores lower than normal in the physical function domains (P<0.01), but were comparable in the mental health domains (P>0.05). Radiolucent lines and bone atrophy related to stress shielding by distal fixation were found in the periprosthetic Gruen Zone I (19.8, 16.8%) and VII (10.3, 27.1%) of the proximal femur.

DISCUSSION

Whereas the rate of aseptic cup failures of the cementless spongy metal Lübeck hip prosthesis is among the best, the failure rate of the stems is attributable to osteolysis of the proximal femur. The fractures of the stem may be attributed to the combination of the lack of proximal support, the fully porous stem made of a cast cobalt-chrome-molybdenum alloy, and the narrow dimension of the stem core. The long-term results of the spongy metal cup are good, whereas the high loosening and fracture rate of fully coated stem are a source of concern especially with regard to the difficult revision scenario with frequent massive bone loss.