The purpose of the present prospective intervention study was to evaluate voluntary isometric force production, relaxation and activation capacity of the quadriceps femoris (QF) muscle before and 6 months after unilateral total knee arthroplasty (TKA). TKA was performed in ten women with primary knee osteoarthritis (OA) using the condylar endoprostheses. Isometric maximal voluntary contraction (MVC) force, rate of force development at 50% of MVC (RFD50) and their ratio to body mass, half-relaxation time (HRT) and voluntary activation (VA) of the QF muscle were recorded in patients for operated and non-operated leg before and 6 months after TKA. Established characteristics were compared with data on the dominant leg of ten age- and gender-matched controls. The clinical examination was performed using the Knee Society System (KSS) scores and pain intensity was assessed by visual analogue scale. MVC force in operated leg was lower (P < 0.05) before and 6 months after TKA as compared with the non-operated leg (31 and 32%, respectively) and controls (48 and 44%, respectively). Patients had lower (P < 0.05) VA of the QF muscle in operated leg 6 months after TKA as compared to controls. Significant increase (P < 0.05) of KSS clinical scores and the tendency for the increasing of explosive force production of QF muscle in the operated leg were observed 6 months after TKA (RFD50 was 60% lower before TKA and 40% lower 6 months after surgery as compared to controls). When compared with the preoperative value, HRT prolongation (P < 0.05) was noted 6 months after TKA in QF muscle of both legs in patients. Therefore, the present study confirmed that patients with knee OA had reduced force generation ability of QF muscle before TKA and the improvement of explosive force was noted 6 months after surgery.

Aim: To analyse the changes in fracture rate, bone density and histology in children with Osteogenesis imperfecta receiving treatment with alendronate (oral bisphosphonate) and calcitriol. Methods: Children treated at Tartu University Hospital from 1995 to 2001 were examined for Osteogenesis imperfecta. Radiographs and bone density measurements were obtained for all patients at the beginning of the study. Four patients also had bone biopsies prior to and one year after beginning treatment. The children were then given alendronate in weight‐dependent dosages and also calcitriol. The number of fractures during the treatment period was recorded and follow‐up bone density measurements were made. Results: Fifteen patients were treated during the 6‐y period; mean follow‐up approximately 3 y. It was found that the number of bone fractures had decreased significantly (p < 0.0001). Bone density improved in all 15 patients. Histologic studies revealed an increased number of osteoblasts and thickness of bone trabeculae as well as a more regular bone lamellar structure at the time of the second operation. Conclusion: The complex treatment of Osteogenesis imperfecta should include alendronate and calcitriol to decrease fractures and improve bone mineral density.

Prospective comparative study, Level II.

Background and Objective. The aim of this study was to compare the leg extensor muscle strength, the postural stability, and the fear of falling in the women with severe knee joint osteoarthritis (OA) before and after a 2-month home exercise program (HEP). Material and Methods. In total, 17 women aged 46–72 years with late-stage knee joint OA scheduled for total knee arthroplasty participated in this study before and after the 2-month HEP with strengthening, stretching, balance, and step exercises. The isometric peak torque (PT) of the leg extensors and postural stability characteristics when standing on a firm or a foam surface for 30 seconds were recorded. The fear of falling and the pain intensity (VAS) were estimated. Results. A significant increase in the PT and the PT-to-body weight (PT-to-BW) ratio of the involved leg as well as the bilateral PT and the PT-to-BW ratio was found after the 2-month HEP compared with the data before the HEP (P<0.05). The PT and the PT-to-BW ratio of the involved leg were significantly lower compared with the uninvolved leg before the HEP (P<0.05). The center of the pressure sway length (foam surface) decreased significantly after the HEP (P<0.05). Significant correlations were found between the PT of the involved leg and the bilateral PT and the fear of falling and between the PT of the involved leg and the postural sway (foam surface) before the HEP. Conclusions. After the 2-month HEP, the leg extensor muscle strength increased and the postural sway length on a foam surface decreased. The results indicate that the increased leg extensor muscle strength improves postural stability and diminishes the fear of falling in women with latestage knee joint OA.

We studied 178 patients undergoing total hip arthroplasty (66 men and 112 women) retrospectively, with regard to the incidence and severity of heterotopic ossification and the significance of postoperative prophylaxis with non-steroid anti-inflammatory drugs. The overall incidence of heterotopic ossification was 32% 1 year after surgery. The factors increasing the incidence were male gender, previous arthroplasty of the contralateral hip joint, previous surgery on the hip, absence of preoperative treatment with non-steroidal anti-inflammatory drugs and an operating time of more than 100 min. The incidence of heterotopic ossification was lower in the patients of 0 blood group.Résumé Nous avons étudié la fréquence et la sévérité d'ossification hétérotopique dans 178 cas d'arthroplastie totale de la hanche avec une prophylaxie postopératoire par AINS. Une année après la chirurgie la fréquence totale était de 32%. Les facteurs qui augmentent le risque étaient le sexe masculin, une arthroplastie de la hanche contrelaterale, des antécédents chirurgicaux sur hanche, l'absence de traitement préopératoire par AINS et une durée opératoire de plus de 100 min. La fréquence d'ossification hétérotopique était inférieure chez les patients du groupe sanguin 0. IntroductionHeterotopic ossification (HO) is a significant complication of total hip arthroplasty (THA). An incidence, without prophylaxis, has been reported of between 8% and 90% [1,13]. Two methods of treatment are commonly used, non-steroidal anti-inflammatory agents (NSAID) and irradiation [5]. The aim of this study was to record the incidence and severity of HO after THA and to determine the relevance of risk factors. Materials and methodsThe notes of 178 patients (66 men and 112 women) who underwent THA in the Clinic of Traumatology and Orthopaedics, Tartu University, between 1995 and 1996 were reviewed retrospectively. The requirement for THA was degenerative arthritis in 160 cases, rheumatoid arthritis in nine cases and trauma of the hip in nine. All patients were treated prophylactically with NSAIDs up to 30 days postoperatively. All patients also received antithrombotic prophylaxis with 0.3 ml (2500 IU) fractioned heparine (Fraxiparine) daily. The prostheses used were all cemented; Lubinus IP in 120 cases, Lubinus SP II in 51 cases and the Link Dysplasia hip prosthesis in seven. In all cases the posterolateral approach was used.The data collected included age, gender, diagnosis, surgery on the ipsi-and contralateral hip performed before or after THA, the operating time, the type of anaesthesia, blood loss and preoperative treatment with NSAIDs. The preoperative anteroposterior radiographs were reviewed, and those taken on the 1st postoperative day and at 3, 6, 9 and 12 months postoperatively, and were assessed according to the Brooker classification, in which HO is classified at stages I-IV, of which stages III and IV are clinically and functionally significant [4].The analysis of preoperative radiographs included the assessment of osteophytes and the s...