Comparison of osteolysis around 3 different cement restrictors in total hip arthroplasty.

BACKGROUND AND AIM: Several studies reported osteolysis around polyethylene glycol/polybutylene terephthalate (PEG/PBT) based femoral cement restrictors. Our goal was to evaluate and compare osteolysis around 3 different plug designs: the slow biodegradable PEG/PBT cement restrictor; the fast biodegradable gelatin cement restrictor; and the non-biodegradable polyethylene plug. PATIENTS AND METHODS: In a retrospective multicentre cohort study chart data were extracted of patients who received a total hip arthroplasty between 2008 and 2012. A total of 961 hips were included. Cortical ratio between inner and outer cortices at the centre of the plug was measured on routine postoperative follow-up moments. Median follow up of all 3 hospitals was 3.5 years (1.4-7.3). The primary outcome was evidence of osteolysis (i.e. the difference in cortical ratio [CR]) on anteroposterior (AP) radiographs at final follow-up. RESULTS: Progressive osteolysis was found around the PEG/PBT cement restrictor represented by a significantly increasing cortical ratio (ΔCR 0.067 (95% CI, 0.063-0.071). Distance from tip prosthesis to plug and size of the plug were found to be independent factors in predicting increased cortical ratio. CONCLUSIONS: Our multicentre cohort shows increase of cortical ratio around the PEG/PBT cement restrictor which progresses over time. Physicians should be aware of this fact and are advised to intensify follow-up of patients who received this cement restrictor.

Long-term outcomes of the Bi-Metric proximally hydroxyapatite-coated femoral stem.

PURPOSE: Promising clinical results and survival rates have been reported for the Bi-Metric proximally hydroxyapatite (HA)-coated femoral stem in short- and mid-term studies. In this study we evaluated the long-term survival as well as clinical and radiological results of this stem. METHODS: From 1992 to 1998 we prospectively included 112 consecutive patients who received a total hip arthroplasty (THA) with an uncemented proximally HA-coated Bi-Metric femoral component (Biomet).At 3 months, 1 year and thereafter every 2 to 3 years, patients were clinically and radiologically monitored. Primary endpoint was revision of the stem for any reason. Secondary endpoints were survival of the cup and THA, radiological characteristics and clinical scores (HHS, HOOS, SF-36 and VAS). RESULTS: Median follow-up was 20 (16-22.25) years. Median age at surgery was 52 (22-63) years. At final follow-up, survival analysis showed an all-cause stem survival of 96.8% (95% CI, 93.3-100). Median HHS scores improved from 57 preoperatively to 94 at final follow-up (p<0.001). At final follow-up the median HOOS score was 80 (9-100); median SF-36 score 71 (18-100); median VAS pain score at rest 0 (0-6) and during activity 0 (0-10). CONCLUSIONS: In this prospective cohort study the 20-year survival rate of the Bi-Metric proximally HA-coated femoral stem was excellent.

[Sinus pericranii; a congenital swelling on the scalp]. / Sinus pericranii; een congenitale zwelling op het behaarde hoofd.

BACKGROUND: Sinus pericranii is a rare congenital disorder of the skull. It involves a venous connection between the intracranial and extracranial venous systems caused by a defect at the level of a cranial sinus. CASE DESCRIPTION: We present the case of a 20-year-old woman with a soft compressible swelling on the back of her head from birth. MRI examination revealed sinus pericranii. The treatment consisted of coagulating the venous connection and closing the cranial malformation. CONCLUSION: In a patient with soft-tissue swelling on the back of the head that has been present since birth, differential diagnostics should extend beyond epidermoid cysts alone and also include consideration of sinus pericranii. This is particularly important if the swelling is in the midline.

Excellent results with the cemented Lubinus SP II 130-mm femoral stem at 10 years of follow-up: 932 hips followed for 5-15 years.

BACKGROUND AND PURPOSE: The Lubinus SP II stem is well documented in both orthopedic registries and clinical studies. Worldwide, the most commonly used stem lengths are 150 mm and 170 mm. In 1995, the 130-mm stem was introduced, but no outcome data have been published. We assessed the long-term survival of the Lubinus SP II 130-mm stem in primary total hip arthroplasty. PATIENTS AND METHODS: In a retrospective cohort study, we evaluated 829 patients with a Lubinus SP II primary total hip arthroplasty (932 hips). The hips were implanted between 1996 and 2001. The primary endpoint was revision for any reason. The mean follow-up period was 10 (5-15) years. RESULTS: Survival analysis showed an all-cause 10-year survival rate of the stem of 98.7% (95% CI: 99.7-97.7), and all-cause 10-year survival of the total hip arthroplasty was 98.3% (95% CI: 99.3-97.3). INTERPRETATION: Excellent long-term results can be achieved with the cemented Lubinus SP II with the relatively short 130-mm stem. This stem has potential advantages over its 150-mm and 170-mm siblings such as bone preservation distal to the stem, better proximal filling around the prosthesis, and easier removal.

[A man with a swollen shoulder]. / Een man met een gezwollen schouder.

A 25-year-old patient presented to the Emergency Department with a swollen left shoulder after an epileptic seizure. Radiography showed a fracture of the humeral head. A CT-scan of the shoulder confirmed the diagnosis of an avulsion fracture of the lesser tuberosity. This is a rare condition and deserves specific attention and surgical treatment to prevent impaired function of the shoulder due to muscle weakness and impingement of the avulsion fragment.

Factors that influence femoral neck length. Analysis of 1543 patients with advanced osteoarthritis of the hip.

BACKGROUND AND PURPOSE: There is little known about the relationship between patient characteristic and the variance in geometrical properties of the femoral neck. The length of the femoral neck is relevant when considering a femoral neck preserving hip replacement. Based on surgical experience we hypothesised that femoral neck length (FNL) decreased with age. We investigated whether certain patient characteristics were related to FNL and the femoral head diameter/FNL ratio. PATIENTS AND METHODS: The femoral neck length of 1543 patients with osteoarthritis grade 3 and 4 was measured on calibrated pelvic radiographs. RESULTS: Increasing age and height were associated positively, while increasing CCD angle and femoral head diameter were associated negatively with femoral neck length. Female gender and height were associated negatively and CCD angle positively with the femoral head diameter/FNL ratio. The FNL in 10 year older individuals was on average 0.2 mm (1%) longer. Moreover, every 10 extra degrees in CCD coincided with a neck length decrease of 1.5 mm (8%) in our population. INTERPRETATION: It seems justified to conclude that age is not a clinical relevant factor in the indication for femoral neck preserving hip arthroplasty. In this respect, CCD angle seems the most clinical relevant factor. Severe valgus angled hips are not a very suitable indication for femoral neck preserving prosthesis.