Scaphoid, lunate and capitate kinematics in the normal and ligament deficient wrist: A bi-plane X-ray fluoroscopy study.

The ligamentous structures of the wrist stabilise and constrain the interactions of the carpal bones during active wrist motion; however, the three-dimensional translations and rotations of the scaphoid, lunate and capitate in the normal and ligament deficient wrist during planar and oblique wrist motions remain poorly understood. This study employed a computer-controlled simulator to replicate physiological wrist motion by dynamic muscle force application, while carpal kinematics were simultaneously measured using bi-plane x-ray fluoroscopy. The aim was to quantify carpal kinematics in the native wrist and after sequential sectioning of the scapholunate interosseous ligament (SLIL) and secondary scapholunate ligament structures. Seven fresh-frozen cadaveric wrist specimens were harvested, and cycles of flexion-extension, radial-ulnar deviation and dart-thrower's motion were simulated. The results showed significant rotational and translational changes to these carpal bones in all stages of disruptions to the supporting ligaments (p < 0.05). Specifically, following the disruption of the dorsal SLIL (Stage II), the scaphoid became significantly more flexed, ulnarly deviated, and pronated relative to the radius, whereas the lunate became more extended, supinated and volarly translated (p < 0.05). Sectioning of the dorsal intercarpal (DIC), dorsal radiocarpal (DRC), and scaphotrapeziotrapezoid (STT) ligaments (Stage IV) caused the scaphoid to collapse further into flexion, ulnar deviation, and pronation. These findings highlight the importance of all the ligamentous attachments that relate to the stability of the scapholunate joint, but more importantly, the dorsal SLIL in maintaining scapholunate stability, and the preservation of the attachments of the DIC and DRC ligaments during dorsal surgical approaches. The findings will be useful in diagnosing wrist pathology and in surgical planning.

Early unprotected return to contact sport after metacarpal fixation in professional athletes.

AIMS: To determine whether an early return to sport in professional Australian Rules Football players after fixation of a non-thumb metacarpal fracture was safe and effective. PATIENTS AND METHODS: A total of 16 patients with a mean age of 25 years (19 to 30) identified as having a non-thumb metacarpal fracture underwent open reduction and internal plate and screw fixation. We compared the players' professional performance statistics before and after the injury to determine whether there was any deterioration in their post-operative performance. RESULTS: Of the 16, 12 sustained their fracture during the season: their mean time to return to unrestricted professional play was two weeks (1 to 5). All except two of the 48 player performance variables showed no reduction in performance post-operatively. CONCLUSION: Our data suggest that professional athletes who sustained a non-thumb metacarpal fracture can safely return to professional play without restriction two weeks after internal fixation. Cite this article: Bone Joint J 2017;99-B:1343-7.

Assessment of normal trapeziometacarpal joint alignment.

The purpose of this study was to determine the alignment of the normal trapeziometacarpal joint and any changes in its alignment with age. Radial, dorsal and dorsoradial subluxation were measured on computerized tomographic scans in 50 joints of 50 adults aged 18 to 62. There were statistically significant correlations between increasing age and dorsoradial subluxation but no significant correlation with dorsal and radial subluxation. Significant dorsoradial subluxation occurs after 46 years of age in the normal trapeziometacarpal joint. A mean dorsoradial subluxation of 21% (range 14%-30%) can be considered normal in this age group.

Comparison of functional and radiological outcomes after computer-assisted versus conventional total knee arthroplasty: a matched-control retrospective study.

PURPOSE: To compare the radiological and functional outcomes of patients who underwent either computer-assisted or conventional total knee arthroplasty (TKA). METHODS: Two groups of 50 patients each underwent either computer-assisted or conventional TKA were retrospectively studied. Patients were matched according to body mass index (BMI), gender, and age. Three senior orthopaedic surgeons with comparable experience performed all surgeries, using 3 different prostheses. The surgical approach and peri- and postoperative regimens were the same. The mechanical axis and the tibial and femoral angles were measured using standardised long-leg weight-bearing radiographs. Overall function was assessed using the Short Form-12 (SF-12) and International Knee Society (IKS) scores. RESULTS: No intra-operative technical difficulties were encountered in either group. The computer-assisted group resulted in more consistent and accurate alignments in both the coronal and sagittal planes and better SF-12 and IKS scores. In obese patients (BMI=30 kg/m2 or more), computer-assisted TKA provided better alignment than the conventional technique. CONCLUSION: Computer-assisted TKA improves implant positioning, limb alignment, and overall functional outcome. It may be particularly advantageous for obese patients.

Pigment epithelium-derived factor overexpression inhibits orthotopic osteosarcoma growth, angiogenesis and metastasis.

Despite significant improvements, the current management of primary osteosarcoma is still limited by the development of metastatic disease, which occurs in approximately 30% of patients despite aggressive multiagent chemotherapy and tumor-ablative surgery. Therefore, there is a need for the development of novel agents to improve the outcome of these patients. Pigment epithelium-derived factor (PEDF) has been shown to be one of the most potent inhibitors of angiogenesis, and more recently has demonstrated a functional role in tumor growth, invasion and metastasis. In this study we report, for the first time, the multitargeted role of PEDF in the inhibition of growth, angiogenesis and metastasis of two orthotopic models of osteosarcoma (rat UMR 106-01 and human SaOS-2). Through stable plasmid-mediated gene transfer of full-length human PEDF, we show that PEDF overexpression significantly reduced tumor cell proliferation (P<0.05) and Matrigel invasion (UMR(PEDF), P<0.001; SaOS(PEDF), P<0.05) and increased adhesion to collagen type-1 (P<0.01), in vitro. In vivo, PEDF overexpression dramatically suppressed orthotopic osteosarcoma growth (P<0.05) and the development of spontaneous pulmonary metastases (UMR(PEDF), P<0.05; SaOS(PEDF), P<0.001). Furthermore, PEDF-overexpressing tumors exhibited reduced intratumoral angiogenesis, evidenced by a significant decrease in microvessel density (P<0.05). Therefore, together these results suggest that PEDF may be a new and promising approach for the treatment of osteosarcoma.

Salvaging the limb salvage: management of complications following endoprosthetic reconstruction for tumours around the knee.

INTRODUCTION: Limb-salvage surgery, including endoprosthetic reconstruction after tumour resection, has become the standard management for local control of tumours around the knee. As the nature of surgery is technically complex and demanding, there is potential for significant morbidity arising from complications. This study describes our experience with complications following endoprosthetic reconstruction around the knee. METHODS: Retrospective analysis of consecutive resections and endoprosthetic reconstructions for tumours around the knee between 1996 and September 2005 performed at St Vincent's Hospital, Melbourne. RESULTS: Fifty consecutive cases were reviewed, with a median follow-up of 24.5 (range, 2-124) months. Median age was 41 (range, 13-79) years. Tumour types included 38 primary musculoskeletal malignancies, 8 metastatic tumours, 2 bony lymphomas and 2 benign lesions. There were eight deaths, nine cases of subsequent metastatic spread and no local recurrences. There were six cases of deep infection, two each of non-resolving nerve palsy, fracture and mechanical wear, and one each of symptomatic patellofemoral impingement, aseptic loosening and intraoperative popliteal artery trauma. Five patients required endoprosthetic revision, and three subsequent amputations were described. Excellent functional outcome and emotional acceptance was observed amongst patients that underwent revision. CONCLUSION: Resection and endoprosthetic reconstruction of tumours around the knee is both technically challenging and resource-intensive. It is imperative that morbidity from complications is limited through the minimisation of their incidence and the provision of optimal management. This series demonstrates that good patient outcomes can be achieved in specialist centres with experienced surgeons and adoption of a multidisciplinary approach.

Pelvic reconstruction using saddle prosthesis following limb salvage operation for periacetabular tumour.

PURPOSE: To assess the clinical results of pelvic reconstruction using a saddle prosthesis following limb salvage operation for periacetabular tumour. METHODS: 12 patients with sarcoma and 4 with metastasis involving the pelvis were treated using the saddle prosthesis between 1995 and 2003 inclusive. Wide pelvic resection was performed for all patients with sarcoma and one with a metastatic lesion; intralesional excision of the acetabulum was undertaken for the remaining 3 patients with metastatic lesions. Oncologic prognosis, operation time, postoperative function, and complications were assessed retrospectively. RESULTS: Of the 12 patients with sarcomas, 5 were alive without evidence of recurrence after a mean follow-up of 37 months, one was alive with disease, 3 died of the disease, and 3 of other medical conditions. Respective mean postoperative functional scores according to the Musculoskeletal Tumor Society-International Symposium on Limb Salvage system and the Toronto Extremity Salvage Score were 53 and 64% in patients undergoing wide acetabular resection, and 30 and 42% in patients undergoing intralesional excision of the acetabulum. In patients undergoing wide acetabular resection and intralesional excision of the acetabulum, the mean operation times were 391 and 162 minutes respectively, whereas the mean times to ambulation were 7 and 4 days respectively. Major complications included infection and dislocation. CONCLUSION: Saddle prosthesis arthroplasty is a useful option for pelvic reconstruction following resection of acetabular malignancies. It is associated with a short operation time, rapid recovery, and moderately good postoperative function, but a relatively high risk of complications.