Proximal interphalangeal joint replacement with an unconstrained pyrocarbon prosthesis (Ascension(R)): a long-term follow-up

There have been limited publications that report long-term outcomes of pyrocarbon implants. This report describes both clinical and radiographic long-term results for patients who have been treated with pyrocarbon proximal interphalangeal implants. Thirteen implants in ten patients are reported for an average follow-up of 8.3 years (range 6.2–9.3). All patients were suffering from degenerative joint disease. Five of the 13 digits were free of pain, the remaining eight digits had mild to moderate pain (visual analogue scale 2–5). The average active range of motion was 58° (SD 19°) at latest examination. X-ray results were unremarkable in six digits with an acceptable position of the prosthesis. However, in seven patients significant radiolucent lines (≥ 1 mm) were observed. Three prostheses demonstrated a migration of the proximal component, and one a subsidence of the distal component. Our study does not support the use of this implant for treatment of osteoarthritis of the finger joint owing to high complication rates and limited range of motion

Development and evaluation of an image-free computer-assisted impingement detection technique for total hip arthroplasty

Periprosthetic or bony impingement in total hip arthroplasty (THA) has been correlated to dislocation, increased wear, reduced postoperative functionality with pain and/or decreased range of motion (ROM). We sought to study the accuracy and assess the reliability of measuring bony and periprosthetic impingement on a virtual bone model prior to the implantation of the acetabular cup with the help of image-free navigation technology in an experimental cadaver study. Impingement-free ROM measurements were recorded during minimally invasive, computer-assisted THA on 14 hips of 7 cadaveric donors. Preoperatively and postoperatively the donors were scanned using computed tomography (CT). Impingement-free ROM on three-dimensional CT-based models was then compared with corresponding, intraoperative navigation models. Bony/periprosthetic impingement can be detected with a mean accuracy limit of below 5° for motion angles, which should be reached after THA for activities of daily living with the help of image-free navigation technology

Ultrasound evaluation of the acromioclavicular joint - A correlation of anatomical and sonographical findings Sonometrie des akromioklavikulargelenkes - Korrelation anatomischer und sonographischer befunde

Aim: To compare ultrasound imaging to the anatomy of the acromioclavicular joint. Methods: 13 cadaveric acromioclavicular joints were examined by ultrasound (11 MHz linear array transducer) to determine the limits of the joint capsule and the width of the joint space. The results were compared to macroscopic sections. Results: Anatomical variations were observed. The joint space of one specimen was completely filled by fibrous tissue, leaving 12 specimens for a complete study. A hypoechoic meniscoid disc was attached to the superior joint capsule, resulting in a convex curvature of the cranial part. The mean sonographic width of the joint space was 3.9 mm ± 1.7 mm standard deviation (SD). The mean distance of the joint capsule from the articular bone rim of the clavicle, the acromion, and from the middle of the joint space was 1.1 ± 1.0 mm, 1.3 ± 0.7 mm, and 2.1 ± 0.9 mm, respectively. The distance from the joint space to the capsular insertion on the clavicle and on the acromion was 4.4 ± 1.4 mm and 5.3 ± 2 mm, respectively. The mean difference between ultrasound and anatomical measurements in the vertical (cranio-caudal) plane was 0.5 ± 0.5 mm (SD), whereas the mean difference between measurements in the horinzontal (medio-lateral) plane was 1.3 ± 1.1 mm (SD). Conclusion: Due to low cost, safety and wide availability, sonography is suited for the evaluation of the acromioclavicular joint. However, when interpreting the results, errors in measuring, limitations in resolution of the system used, and the anatomy of the acromioclavicular joint and its anatomical variants have to be taken into consideration

MR imaging of the intraarticular disk of the acromioclavicular joint: A comparison with anatomical, histological and in-vivo findings

Objective: To characterize MRI features of the intraarticular disk of the acromioclavicular joint. Design: We studied the appearance of 11 acromioclavicular joints of six cadavers (subjects aged 57-89 years at the time of death) and six healthy shoulders on T1-weighted, T2 (TSE)-weighted, STIR and PD (fat saturated) magnetic resonance imaging (MRI) and compared the findings with observations during dissection and histological examination. Results: Macroscopic examinations showed two wedge-shaped disks underneath the superior and above the inferior joint capsule in nine specimens. In two specimens the acromioclavicular joints were degenerated. Histologically, the disk tissue consisted of fibrocartilage whereas the joint cartilage was partly degenerated, containing zones of fibrocartilage amidst degenerated hyaline cartilage, which may explain the similar signal intensity of both structures in all sequences used. MR appearance of the intraarticular structures of the acromioclavicular joint was similar in cadaveric and healthy shoulders. Conclusions: The difficulties related to imaging the acromioclavicular joint may be explained by the anatomy. Similar signal intensity of cartilage and disk may be explained by their similar histological structure (fibrocartilage). MRI findings should be interpreted with respect to the variable anatomy. These results may serve as a basis for further radiological studies of the acromioclavicular joint

Current therapeutic strategies of heterotopic ossification – a survey amongst orthopaedic and trauma departments in Germany

Background Heterotopic ossification (HO) is a complication after tissue trauma, fracture and surgery (i.e. total hip arthroplasty). Prophylaxis is the most effective therapy. If HO formations become symptomatic and limit patients’ quality of life, revision surgery is indicated and is usually combined with a perioperative oral prophylaxis (NSAIDs) and/or irradiation. However, a long-term use of NSAIDs can induce gastro-intestinal or cardiac side-effects and possible bony non-unions during fracture healing. Subject of this study was to assess the current status of HO prophylaxis after injuries or fractures and to evaluate current indications and strategies for excision of symptomatic HO. Methods Between 2013 and 2014, a questionnaire was sent to 119 orthopaedic and trauma surgery departments in Germany. Participation was voluntary and all acquired data was given anonymously. Results The cumulative feedback rate was 71 %. Trauma and orthopaedic surgery departments in Germany recommend oral HO prophylaxis after acetabulum and femoral neck fractures, elbow dislocation, and fracture or dislocation of the radial head. Pain upon movement and an increasing loss of range of motion in the affected joint are considered to be clear indications for HO surgery. A partial removal of ROM-limiting HO formations was also considered important. The vast majority of all departments include perioperative oral HO prophylaxis and/or irradiation if surgical HO removal is planned. The choice and duration of NSAIDs is highly variable. Conclusion HO is of clinical significance in current traumatology and orthopaedics. Certain fractures and injuries are prone to HO, and prophylactic measures should be taken. The respondents in this survey assessed current therapeutic strategies for HO formations similarly. These concepts are in line with the literature. However, the duration of perioperative oral HO prophylaxis varied greatly among the specialist centres. This is significant as a long-term use of NSAIDs fosters a potential risk for the patients’ safety and could influence the clinical outcome. National and international guidelines need to be developed to further reduce HO rates and improve patients’ safety in trauma and orthopaedic surgery