Cemented Dual Mobility Cup for Primary Total Hip Arthroplasty in Elder Patients with High-Risk Instability

Several studies have shown that double mobility (DM) cups reduce postoperative dislocations. Does the cemented dual mobility cup reduce dislocations in a specific cohort of elder patients with a high dislocation risk? Our hypothesis is that this implant is optimal for elder patients because it reduces early dislocation. We have retrospectively reviewed elder patients who underwent total hip arthroplasty (THA) with cemented double mobility cup between March 2009 and January 2018. The inclusion criteria were patients (>75 years) who were operated on for primary THA (osteoarthritis or necrosis) with a cemented dual mobility cup and a high-risk instability (at least two patient-dependent risk factors for instability). The exclusion criteria were revision surgeries or hip fracture. In all the cases, the same surgical approach was performed with a Watson Jones modified approach in supine position. We have collected demographic data, instability risk factors. Patients were classified using the Devane's score, Merle d'Aubigné score and the patient's likelihood of falling with the Morse Fall Scale. Surgical and follow-up complications were collected from their medical history. Sixty-eight arthroplasties (68 patients) were included in the study. The median age was 81.7 years (SD 6.4), and the American Society of Anesthesiologists (ASA) score showed a distribution: II 27.94%, III 63.24% and IV 8.82%. Devane's score was less than five in all of the cases. At least two patient-dependent risk factors for instability (87% had three or more) were present in each case. The median follow-up time was 49.04 months (SD 22.6). Complications observed were two cases of infection and one case of aseptic loosening at 15 months which required revision surgery. We did not observe any prosthetic dislocation. The cemented dual mobility cup is an excellent surgical option on primary total hip arthroplasties for elder patients with high-risk instability.

Reconstruction of the extensor mechanism with fresh-frozen tendon allograft in total knee arthroplasty

PURPOSE

Patellar tendon rupture after total knee replacement is a rare and highly limiting injury with multifactorial aetiology. Many reconstruction techniques have been described with not very predictable results. The use of allografts has been accepted as a suitable solution.

METHODS

A series of seven patients with patellar tendon rupture treated with fresh-frozen tendon allograft reconstruction after knee arthroplasty is presented.

RESULTS

Median follow-up is 25 months (20-31). Functional assessment improved, and the knee society score and knee functional score improved from 26 and 16 to 82 and 55, respectively. Median extension lag was 5° (0°-20°), with a median range of motion of 95° (70-100). Radiological study showed a rise of the patella of 22.26 mm.

CONCLUSION

The use of fresh-frozen allografts as a solution to patellar tendon ruptures after knee arthroplasty seems to provide acceptable results. Increased patellar height does not seem to affect functionality.

LEVEL OF EVIDENCE

Case series, Level IV.

Nail-patella syndrome: long term evolution

Nail-patella syndrome is a rare dysplasia characterized by a typical tetrad: hypoplasic nails, hypoplasic or absent patella, radial head dislocation and iliac horns. We review eight patients, four men and four women, aged from 20 to 70 years. The main complaint at consultation was with their knees due to patellar instability and pain. Five of them required surgical treatment due to patellar dislocation and three patients were not treated. The Krogius-Lecène procedure was performed in four patients with a good result following the Insall classification of pain and instability and with an average follow-up of 24 years (range, 18-28 years). Patellectomy was performed in the eldest patient due to femoropatellar arthritis present at first consultation. No patients presented with elbow or nail disorders or with iliac horns.