Total knee arthroplasty at 15-17 years: does implant design affect outcome?

PURPOSE: A study was conducted to compare minimum 15-year survivorship and outcome of the Genesis I and II implants for total knee arthroplasty (TKA). METHODS: We retrospectively reviewed 245 consecutive TKA implanted between January 1995 and October 1997. Genesis I was implanted in 156 knees and Genesis II in 89 knees. RESULTS: At 15-17 years, 75 patients (31%) had died, 28 patients (11%) were lost to follow-up and 11 TKA were revised (4.6%), including ten Genesis I (6.4%) and one Genesis II (1.1%); 131 TKA (53%) were available for follow-up. Cumulative survivorship was 92.4% at 15.7 years. Survival in patients <69 years at surgery was lower (88.0%) compared with patients ≥69 years (98.5%; p = 0.023). In patients <69 years, Genesis I survival (84.3%) was worse compared with Genesis II (97.1%) (p = 0.018). Polyethylene (PE) Insert thickness ≤11 mm had significantly better survivorship (97.1%) compared with PE >11 mm (56.7%) (p < 0.0001) CONCLUSIONS: At a minimum of 15 years, the overall (92.4%) survivorship of Genesis TKA was good, with excellent (98.1%) survivorship of the Genesis II design. Revision rates were higher with Genesis I in the younger age group and with insert thickness >11 mm, possibly due to longer shelf life of less frequently used sizes.

Unilateral congenital dislocation of the knee and hip: a case report.

We report our experience with a unilateral congenital dislocation of the knee associated with a developmental dysplasia of the hip on the same side. Our case is a good example of congenital dislocation of the knee caused by abnormal intrauterine pressure leading to this type of congenital postural deformity. To our knowledge this is the first case of congenital dislocation of the knee reported after cervical cerclage of an incompetent cervix to prevent a pre-term delivery. The Pavlik Harness was used to treat the knee and the hip at the same time with a satisfactory result after 20 months of follow-up.

Posttraumatic cyst-like lesions of cortical bone in children.

Cyst-like cortical defects appearing after minor greenstick fractures in children have occasionally been described. These lesions are asymptomatic and appear just proximal to the fracture line within the area of subperiostal new bone formation. Although the pathogenesis of these lesions remains conjectural, complete resolution occurs, without adverse effect on fracture healing. Only a few cases of these posttraumatic cysts have been previously reported, mainly in radiological literature. We present a case of cyst formation after a greenstick fracture of the distal radius. We discuss the evolution of these post fracture cysts and review the current theories on their pathogenesis.

Predictors of Recovery After Conservative Treatment of AO-Type A Thoracolumbar Spine Fractures Without Neurological Deficit.

STUDY DESIGN: Prospective, correlational, exploratory, clinical research. OBJECTIVE: To identify the factors determining a patient's recovery after conservative treatment of compression fractures of the thoracolumbar spine. SUMMARY OF BACKGROUND DATA: The reported results of compression fractures are poor. These results are not influenced by the severity of compression, the fracture site, or the residual deformity. Otherwise, the factors that determine a patient's recovery are unknown. METHODS: In 48 conservatively treated patients the preinjury versus the 12-month follow-up differences (Δ) in back pain (visual analogue scale for pain), Oswestry disability index (ODI), and the Greenough and Fraser low back outcome scale were prospectively recorded. For these differences and for time lost from work and satisfaction, multiple linear regressions with combinations of 16 factors were performed. RESULTS: At 1 year, patients with an income-insurance were 9% (P = 0.096) more disabled than those without. They reported a 15% less favorable global outcome and 27% less participation. Smokers were 13% (P = 0.010) more disabled and 11% (P = 0.044) less satisfied. With each increase of the AO-fracture type from A1 to A3 the disability was 8% worse. Patients with pre-existent chronic low back pain (CLBP) returned two points (on a visual analogue scale [VAS] pain total of 10) more closely (P = 0.041) to their preinjury pain level than those without but were 21% (P = 0.001) less satisfied. Our model offers an explanation for more than 25% of the variability of ΔODI and of the satisfaction. For sick leave, no significant predictors were found. CONCLUSION: Smoking and insurance status are the strongest negative predictors for recovery. LBP patients returned more closely to their preinjury back pain level, but were less satisfied. The AO fracture type had a marked influence on disability, the sagittal deformity had not. The time lost from work did not depend on patient or injury-related factors. LEVEL OF EVIDENCE: N/A.