Osteointegrative Sleeves for Metaphyseal Defect Augmentation in Revision Total Knee Arthroplasty: Clinical and Radiological 5-Year Follow-Up.

BACKGROUND: Cementless metaphyseal implant fixation of revision total knee arthroplasty has encouraging early results. We analyzed midterm results and implant survival of osteointegrative augments in Anderson Orthopedic Research Institute (AORI) type 2a, 2b, and 3 defects. Reasons for implant failure were explored and the potential for anatomic joint line reconstruction evaluated. METHODS: Sixty-seven consecutive patients (68 revision total knee arthroplasties) received cementless metaphyseal sleeves between 2011 and 2014. The mean follow-up was 5.0 years, mean age was 68.5 years, and mean body mass index was 31.4 kg/m2. The clinical and radiographic results were determined using established scoring systems. Additionally, the survival rate was calculated and reasons for failure were analyzed. RESULTS: In 2 patients (4.3%), sleeves had to be removed early postoperatively for deep infection after second-stage reimplantation. With continuously functioning remaining implants, the aseptic survival rate was 93.6%. Cleared up for initial technical issues due to poor bone quality, it is as high as 98%. The scores remained to be significantly improved by 64.8 points (Western Ontario and McMaster Universities Osteoarthritis Index) and 25.8 points (Knee Society score) (P < .001). In 10 patients (29.4%), diaphyseal radiolucencies were observed without suspicion of loosening. The mean joint line was noted to be 0.36 mm lower to the anatomic level. CONCLUSION: At a mean follow-up of 5.0 years, cementless osteointegrative sleeves for metaphyseal fixation in AORI 2a, AORI 2b, and AORI 3 defects yielded continuous implant fixation even in cases with preceding revisions. The cleared up aseptic survival rate was 98% at 5 years. The modular sleeve design allowed joint line reconstruction near the anatomic level.

[Influence of Comorbidities on Revision Rate within the First Year after Primary Total Hip Arthroplasty]. / Einfluss von Komorbiditäten auf die Revisionsrate im 1. Jahr postoperativ nach Primärimplantation einer Hüfttotalendoprothese.

Background Total hip arthroplasty (THA) is very frequently performed. Despite low complication rates, revisions play an important clinical and economical role. The aim of this study was to identify comorbid diseases of patients undergoing primary THA and their potential influence on the survival of hip replacements. Patients/Material and Methods A total of 867 patients were included in this retrospective study. All revisions were reviewed that took place at our hospital within one year of primary implantation of THA. Comorbid diseases were detected by administrative data, using the Elixhauser definition, which includes thirty diseases. The Cox regression model and Fisher's exact test were used to examine correlations between comorbidities and risk of revision. Results 41 Patients required re-operation within the first year of surgery. The presence of one or more of the analysed comorbidities was associated with a greater risk of revision. Deficiency anemia, obesity, drug abuse, alcohol abuse, fluid and electrolyte disorders and peripheral vascular disorders were associated with increased risk of revision (p < 0.05 for all comparisons). CONCLUSION: The total number of comorbidities and specific comorbid diseases was independently associated with an increased risk of re-operation within the first year of total hip arthroplasty. This information could be helpful in pre- and post-operative risk adjustment and patient selection.

A short-stem hip implant with metaphyseal anchorage in patients with developmental dysplasia of the hip.

BACKGROUND: Short-stem implants are routinely used for total hip arthroplasty in younger patients that are more likely to have secondary osteoarthritis than older patients. OBJECTIVE: To investigate the applicability of short-stem hip implants for secondary osteoarthritis due to developmental dysplasia of the hip. METHODS: This study analyzed the clinical and radiological results of patients with developmental dysplasia of the hip (DDH, 58 hips) and compared them to those of patients with primary osteoarthritis (POA, 59 hips) treated with the metaphyseal total hip arthroplasty (Metha®) short stem with metaphyseal fixation. RESULTS: The mean clinical and radiological follow-up periods were 2.9 ± 1.1 years and 3.8 ± 1.9 years, respectively. The mean Harris Hip Score (HHS) significantly increased in both groups over this period (p< 0.0001). The caput-collum-diaphysis (CCD) angle was significantly lower in the POA group prior to surgery and significantly increased in the POA and and decreased in DDH groups, respectively. The preoperative femoral offset was lower in the DDH group and increased significantly after surgery. CONCLUSIONS: The Metha® short stem in patients with DDH allows good reconstruction of joint biomechanics with a good clinical outcome.