Cost-effectiveness of cemented versus cementless total hip arthroplasty. A Markov decision analysis based on implant cost.

BACKGROUND: Probabilistic decision analysis is a means of reflecting the uncertainty parameter in models and of presenting it in a comprehensible manner to decision-makers. MATERIALS AND METHODS: A cost-effectiveness model was constructed to compare the cementless and cemented total hip prostheses implanted at our department in terms of lifetime costs and quality-adjusted life-years (QALY). Revision rates were obtained from the Orthopaedic Prosthesis Register of the Laboratory of Medical Technology, Istituti Ortopedici Rizzoli, Bologna, Italy. RESULTS: The risk of early revision (at 5 years of follow-up) for cementless and cemented prostheses was 1.6% and 1.4%, respectively, resulting in equal QALY for the two implant types. Analysis of mean cost and QALY indicated that use of either implant is not associated with cost savings. DISCUSSION: Management with cementless or cemented total hip prostheses in a theoretical cohort of 70-year-old patients with fracture of the femoral neck or arthritis involving the hip is not significantly different according to the probabilistic results from the model.

Investigation of work-related disorders in truck drivers using RULA method.

A high incidence of spinal disorders is observed in professional drivers; in particular, back and neck pain result in high rates of morbidity and low retirement age. A sample of 77 drivers, of rubbish-collection vehicles who sit in a standard posture and of road-washing vehicles, who drive with the neck and trunk flexed, bent and twisted, was studied using RULA, a method for the evaluation of the exposure to risk factors associated with work-related upper-limb disorders. Results showed a significant association between trunk and neck scores and all self-reported pains, aches or discomforts in the trunk or neck regions in all subjects. In particular, the neck score was significant in both postures, reflecting high loading of the neck. Significantly different posture scores were also recorded for drivers using an adjustable vs. a non-adjustable seat. In this first RULA study of the working posture of professional truck drivers, the method proved to be a suitable tool for the rapid evaluation of the loading of neck and trunk.

[Magnetic resonance arthrography in chronic wrist pain]. / Artrografia con Risonanza Magnetica (artro-RM) nelle malattie dolorose croniche del polso.

PURPOSE: To investigate the clinical role of Magnetic Resonance Arthrography (MRA) of the wrist in subjects with chronic pain. MATERIAL AND METHODS: Thirty-five patients complaining of wrist pain for more 6 months were submitted to MRI and MRA. All patients received an intra-articular (monocompartment radiocarpal joint) injection of 2-10 mL of a 10 mmol saline solution of Gd-DPTA. Two radiologists independently evaluated the conspicuity of the intrinsic intercarpal ligaments and of the triangular fibrocartilage complex and expressed it on a 3-grade semiquantitative scale. On MRI images, complete visualization of the two structures was graded as 0, partial visualization as 1 and no visualization as 2. On MRA images, no contrast agent passage through the ligament or the complex was graded as 0, minimal passage as 1 and complete passage as 2. Sixteen patients had surgical confirmation (arthroscopy in 10 and open surgery in 6 patients). RESULTS: On MRI images the scapholunate ligament was completely visualized in 7 patients (21%) and partially or not visualized in 28 patients (89%). MRA images showed an intact ligament in 15 cases (44%) and a partial or total tear in 20 cases (48% and 8% respectively, 56% in all). On MRI images the luno-pyramidal ligament was completely visualized in 6 patients (18%) and partially or not visualized in 29 cases (82%). On MRA images the luno-pyramidal ligament was intact in 21 cases (58%) and had a partial or total tear in 14 cases (27% and 15% respectively, 42% in all). On MRI images the triangular fibrocartilage complex was normal in 27 cases (76%) and it was only partially visualized in 8 cases (24%). On MRA images the triangular fibrocartilage complex was normal in 13 cases (37%) and had a partial injury in 22 cases (63%). There were no severe side-effects to contrast agent injection, nor severe complications. The overall diagnostic accuracy rates of MRI and MRA were 40% and 81% respectively, with sensitivity and specificity of 63% and 39% (MRI) and of 82% and 79% (MRA). CONCLUSIONS: Compared with MRI, MRA can be considered a useful tool for the visualization of interosseous carpal ligaments and of the triangular fibrocartilage complex. MRA also helps detect injuries in these structures.

Lesions of the triangular fibrocartilage in fractures of the wrist.

MRI conducted in 32 cases of distal fracture of the radius a mean of 93 days after trauma allowed for the identification of various lesions of the soft tissues among which those of the triangular fibrocartilaginous complex. These observations confirm the presence of lesions of the triangular fibrocartilaginous complex (TFC) among immediate complications of distal fractures of the radius and the diagnostic role of MRI in post-traumatic ulnar pain.

[Magnetic resonance arthrography in chondral disease of the knee]. / L'artrografia con Risonanza Magnetica nella malattia condrale del ginocchio.

The clinical usefulness of Magnetic Resonance Imaging (MRI) of the knee in the depiction of meniscal, ligament and tendon lesions is well known. In contrast, the role MRI plays in the diagnosis of chondromalacia remains debated, the gold standard being arthroscopy. A new technique, i.e., MR arthrography (MRA), has been recently proposed which consists of the intraarticular injection of a paramagnetic contrast agent (Gd-DTPA) during MRI. Thirty-one patients with clinically suspected chondromalacia of the knee were examined with MRA. The exams were performed with a 1T superconductive magnet and a dedicated coil. All the patients were examined before (baseline scans) and after paramagnetic contrast agent injection. MRA results were compared with arthrographic findings. Baseline MRI had 25% sensitivity, 77.9% specificity and 83% diagnostic confidence in the diagnosis of chondromalacia; these figures increased to 93%, 97.6% and 91.5% after contrast agent injection. This preliminary experience confirms MRA to be a useful tool in the diagnosis of chondral knee conditions.

MR findings in post-traumatic carpal tunnel syndrome.

Stenosis of the canal secondary to poor consolidation of fractures of the distal radial epiphysis is one of the causes of compression on the median nerve of the wrist. Other post-traumatic compressive pathologies of the median nerve when there are no significant skeletal modifications caused by probable involvement of the soft tissues surrounding and within the canal are also described. MR was used to study 23 patients affected with the sequelae of fracture of the radial distal epiphysis who presented with clinical and electromyographic signs of carpal tunnel syndrome, and were submitted to decompressive surgery. MR showed indirect signs of compression, such as morphological changes of the median nerve, as well as post-traumatic changes in the carpal canal. MR allows for a complete anatomical view of the canal structures implicated in causing post-traumatic carpal tunnel syndrome.

[Magnetic resonance in the diagnosis of lesions of the carpal triangular fibrocartilage. The experience with 49 patients with chronic pain at the wrist]. / La Risonanza Magnetica nella diagnosi delle lesioni della fibrocartilagine triangolare del carpo. Esperienza su 49 pazienti con dolore cronico al polso.

In order to evaluate the diagnostic capabilities of MR Imaging in defining triangular fibrocartilage (TFC) lesions, 49 selected patients--21 with rheumatoid arthritis, 13 with traumatic injury and 15 with wrist fracture--presenting chronic wrist pain were examined with MR Imaging. The wrists of 12 healthy subjects were also studied as a control group. MR examinations were performed by means of a superconductive 1.0 T unit (Magnetom-Siemens); SE and GE T1- and T2-weighted pulse sequences were employed to acquire images of the wrists on the coronal, axial and, if necessary, sagittal planes. The results showed peripheral TFC tears in 10 cases, central TFC lesions in 12 cases and TFC lesions with collateral insertion involvement in 9 cases. In 4 patients focal thickening of TFC without disruption was observed. The correct diagnosis was made in all the 19 surgically verified cases. Our experience confirms the clinical value of MR Imaging in the evaluation of TFC lesions in patients with chronic ulnar pain syndrome.

MR imaging in the diagnosis of carpal tunnel syndrome.

Diagnosis of carpal tunnel syndrome (CTS) is usually made on the basis of clinical and electrophysiologic data. Other tests, however, such as ultrasound and CT, have enabled us to acquire additional information regarding the anatomical definition of the structures inside the carpal tunnel. The superior quality of MRIs soft-tissue definition led us to employ it in cases of median nerve compression at the wrist in order to determine its true diagnostic value. We compared the preoperative electrophysiologic and MRI findings in 23 cases of CTS which had undergone surgical decompression of the median nerve at the wrist. Exact correspondence with the intraoperative findings confirmed the reliability of the anatomical information provided by MRI, yet the same comparison revealed that correct "functional" information could be provided only by the electrophysiologic tests.

[Magnetic resonance in the tunnel carpal syndrome. Possibilities and perspectives of an etiopathogenetic study]. / La risonanza magnetica nella sindrome del tunnel carpale. Possibilità e prospettive di studio etiopatogenetico.

Thirty-four selected patients were evaluated in order to define MRI capabilities in the preoperative evaluation and characterization of the pathogenetic patterns of carpal tunnel syndrome (CTS). MRI examinations were performed by means of a superconductive unit (1.0 T, Magnetom): SE T1 (500/17) and T2 (2000/90) axial images of the carpal region were obtained with a round surface coil. In 8 patients 3D GE (FLASH) pulse sequences were used to obtain 32 images of the hand; 3D reconstruction was also applied. Six patients with rheumatoid arthritis and amyloidosis were also studied after i.v. injection of Gd-DTPA (0.2 mM/kg). MRI findings were compared with both clinico-electrophysiologic and surgical results. High agreement was observed only between MRI and surgical findings. MRI allowed the direct demonstration of carpal tunnel abnormalities in 8 cases, while abnormal findings in the median nerve were observed in 18 patients. The possibility of depicting medial nerve lesions on T2-weighted images when no direct demonstration of the cause of compression is possible, could represent a guideline for the etiopathogenetic investigation of CTS. However, further experience in selected patients is necessary to define all the aspects relative to this very common syndrome.

Rotational disorders in intramedullary fixation of the lower limbs.

The routine employment of intramedullary fixation in fractures of the femur and tibia has led the authors to thoroughly evaluate malunions. With the aid of CT scan, precise multilevel quantification of residual rotational deformity was possible by comparison with the contralateral limb after fracture healing. The results of this study confirm the effectiveness of the method, filling an interpretative gap in the literature.

A case of monolateral duplication of the Achilles tendon due to an anomaly of the medial gastrocnemius muscle.

The authors describe the chance finding of a congenital morphological anomaly in the Achilles tendon, characterized by monolateral duplication as a result of anomalous differentiation of the medial gastrocnemius muscle. This may be added to the previous congenital deformities described in the literature (shortness of the Achilles tendon, its duplication as a result of the lack of fusion of the aponeurosis of the soleus and of the gastrocnemii, the presence of a supplementary medial gastrocnemius).

Domed high tibial osteotomy: the long-term results in tibiofemoral arthritis with and without malalignment of the extensor apparatus.

The authors confirm the role of high tibial osteotomy in the correction of valgus and varus anomalies, which are frequently associated with imbalance of the extensor apparatus and with torsional defects of the tibia. This has encouraged the authors to adopt a curvilinear osteotomy capable of correcting anomalies in the various planes. The results are evaluated in subjects with monocompartmental arthritis associated with valgus or varus, as well as for those with associated malalignment of the extensor apparatus. The review is based on 38 operated knees, followed up for 17 to 78 months (average 39 months) after operation.