Introduction: Unicompartmental knee arthroplasty (UKA) is a proven for treatment of knee osteoarthritis (OA). Survival rates have been found comparable with total knee arthroplasty (TKA) in specialty hospitals series, but registry based studies show worse results of survival of UKA. High BMI, age of the patient, patellofemoral arthritis or learning curve have been found to have only mild consequences to the survival rates. Original indications for Oxford UKA in OA are severe pain and full thickness cartilage loss with bone-on-bone contact in the medial side. After widespread use of UKA surgeons are broadening their indications. Purpose of this study was to evaluate the influence of preoperative degree of OA on survival rate of UKA.

Material and Methods: 113 knees in 103 patients were operated with Oxford phase 3 UKA. We evaluated all the patient data retrospectively and patient age, body mass index (BMI), sex, earlier arthroscopies, operation time, follow-up time, preoperative medial joint space widths, reoperations and survival of UKA was recorded

Results: The mean age of the patients was 58 years (38–81) and mean follow-up time was 47 months (3–114). 22 UKAs were revised and the overall survival rate was 80.5%. 68% of revised knees have had undergone arthroscopy before UKA to confirm existence of arthritis. Odds ratio for female gender was statistically non-significant 1.59 (95% CI 0.57–4.45, p=0.46,). For BMI and patient’s age, the association remained non-significant with odds ratios of 1.07 (95% CI 0.98–1.17, p=0.14) and 0.96 (95% CI 0.90–1.02, p=0.19). Patients were divided four sub-groups according medial joint space width (medial joint space width ≤2 mm and > 2 mm) and Lateral/medial joint space width ratio (L/M-ratio ≤2.5 and > 2.5). Over 2 mm medial joint space width or L/M-ratio less than 2.5 were found significant risk factors for revisions, odds ratios being 6.00 (95% CI 2.12–17.00, p< 0.01) and 7.88 (95% CI 2.76–22.54, p< 0.01), respectively.

Discussion: Nowadays UKAs are performed on patients with mild OA against the original indications. In more severe OA varus alignment of the knee causes mechanical overload to the medial compartment, which is well corrected by UKA. Also it is possible that in the cases of prolonged knee pain caution is focused incorrectly to mild OA, which is typical radiological finding even in asymptomatic middle aged and elderly patients. Also in the early phase of OA it is impossible to estimate progression of cartilage damage in other two compartments. In conclusion we suggest that not to extend original indication of UKA and patient should have true medial bone-on-bone OA in preoperative radiographs. Performing UKA for patients with medial joint space width over 2 mm or L/M-ratio less than 2.5 should be concerned particularly careful.

Aims: To assess the paraspinal muscle innervation and endurance in LSSMethods: Study included 25 patients with clinically and radiologically diagnosed LSS. Electromyography (EMG) of the paraspinal muscles was performed at the L3 to S1 levels bilaterally using a concentric needle. At least 20 insertions were analysed from each muscle to detect abnormal spontaneous activity associated with axonal damage (þbrillation potentials, positive sharp waves and complex repetitive discharges). Paraspinal muscle activity during trunk ßexion-extension movement and muscle endurance during dynamic isoinertial back endurance test were assessed by surface EMG. Muscle fatigue was calculated using mean power frequency (MPF) analysis. Results: Abnormal þndings in needle EMG of the paraspinal muscles were observed in 18 out of the 22 (81.8%) examined patients. Abnormal ßexionextension activation of the paraspinal muscles was observed in all examined patients. The MPF change was signiþcantly smaller than in previously evaluated healthy subjects and non-speciþc CLBP patients (P< 0.001) not suffering from symptoms of LSS. Para-spinal muscle fatigability was not associated with the denervation of the muscles. Conclusions: Denervation and abnormal activation of lumbar paraspinal muscles are frequent þndings in non-operated LSS patients. The paraspinal muscle endurance of the patients was unexpectedly good

Aims: To find out if osteosynthesis (OS) or hemiarthroplasty (HA) is better in terms of functional outcome. Patients and methods: In 1989–1996, all displaced cervical hip fractures were prospectively, using the same forms, registered at the University Hospitals of Oulu in Finland and Lund in Sweden. Cross-matchings was performed for age, sex, preoperative residence, and ambulatory capacity. Results: The first study comprised 357 pairs (OS with two hook pins and cementless Austin-Moore HA): OS was associated with a better functional outcome and lower mortality, but a higher re-operation rate than hemiarthroplasty. The second study had 446 pairs (OS two hook pins and cemntless HA): OS was associated with better function and lower mortality than HA, especially in younger patients, and it is recommended as the primary treatment for cervical non-pathological hip fractures in patients younger than 80 years and with good ambulatory capacity, whereas the oldest patients can also be safely treated by HA. The third study comprised 82 pairs (OS with three screws and cementless HA): Functional recovery is slightly better after OS with three screws than after uncemented HA, although no significant differences were seen in a sample of this size. On the other hand, OS is associated with a higher re-operation rate. Conclusion: OS seemed somewhat better in terms of functional outcome.