The extracortical single-button (SB) inlay repair is one of the most preferred distal biceps tendon repair techniques. However, specific complications such as neurovascular injury and non-anatomic repairs have led to the development of techniques that utilize intracortical double-button (DB) fixation.

To compare the biomechanical stability of the extracortical SB repair with the anatomical DB repair technique.

Controlled laboratory study.

The distal biceps tendon was transected in 18 cadaveric elbows from 9 donors. One elbow of each donor was randomly assigned to the extracortical SBor anatomical DB group. Both groups were cyclically loaded with 60N over 1000 cycles between 90° of flexion and full extension. The elbow was then fixed in 90° of flexion and the repair construct loaded to failure. Gap-formation and construct stiffness during cyclic loading, and ultimate load to failure was analysed.

After 1000 cycles, the anatomical DB technique compared with the extracortical SB technique showed significantly less gap-formation (mean difference 1.2 mm; p=0.017) and significantly more construct stiffness (mean difference 31 N/mm; p=0.023). Ultimate load to failure was not significantly different comparing both groups (SB, 277 N ±92 vs. DB, 285 N ±135; p=0.859). The failure mode in the anatomical DB group was significantly different compared with the extracortical SB technique (p=0.002) and was due to fracture avulsion of the BicepsButton in 7 out of 9 specimens (vs. none in SB group).

Our study shows that the intracortical DB technique produces equivalent or superior biomechanical performance to the SB technique. The DB repair technique reduces the risk of nerve injury and better restores the anatomical footprint of biceps tendon. The DB technique may offer a clinically viable alternative to the SB repair technique.

Neer Type-IIB lateral clavicle fractures are inherently unstable fractures with associated disruption of the coracoclavicular (CC) ligaments. A novel plating technique using a superior lateral locking plate with antero-posterior (AP) locking screws, resulting in orthogonal fixation in the lateral fragment has been designed to enhance stability. The purpose of this study was to biomechanically compare three different clavicle plating constructs.

24 fresh-frozen cadaveric shoulders were randomised into three groups (n=8 specimens). Group 1: lateral locking plate only (Medartis Aptus Superior Lateral Plate); Group 2: lateral locking plate with CC stabilisation (Nr. 2 FiberWire); and Group 3: lateral locking plate with two AP locking screws stabilising the lateral fragment. Data was analysed for gap formation after cyclic loading, construct stiffness and ultimate load to failure, defined by a marked decrease in the load displacement curve.

After 500 cycles, there was no statistically significant difference between the three groups in gap-formation (p = 0.179). Ultimate load to failure was significantly higher in Group 3 compared to Group 1 (286N vs. 167N; p = 0.022), but not to Group 2 (286N vs. 246N; p = 0.604). There were no statistically significant differences in stiffness (Group 1: 504N/mm; Group 2: 564N/mm; Group 3: 512N/mm; p = 0.712). Peri-implant fracture was the primary mode of failure for all three groups, with Group 3 demonstrating the lowest rate of peri-implant fractures (Group 1: 6/8; Group 2: 7/8, Group 3: 4/8; p = 0.243).

The lateral locking plate with orthogonal AP locking screw fixation in the lateral fragment demonstrated the greatest ultimate failure load, followed by the lateral locking plate with CC stabilization. The use of orthogonal screw fixation in the distal fragment may negate against the need for CC stabilization in these types of fractures, thus minimizing surgical dissection around the coracoid and potential complications.

Pigment epithelium-derived factor (PEDF) is the most potent endogenous inhibitor of angiogenesis and decreased PEDF expression has been shown, in many tumours, to be associated with increased intratumoural microvascularity, enhanced tumour growth and metastases and poor patient prognosis. We evaluated the role of PEDF in osteosarcoma growth inhibition and examined it’s potential as a possible anti-cancer therapeutic agent.

We investigated the effects of overexpressed and recombinant PEDF (rPEDF) in several cell-based assays and in two orthotopic models of osteosarcoma (UMR 106-01 and SaOS-2).

In vitro, overexpression of PEDF significantly decreased cell proliferation, migration, invasion and increased adhesion to collagen-1. rPEDF resulted in a dose-dependent inhibition of cell proliferation, increased collagen adhesion, decreased invasion, and down-regulation of VEGF. The pro-differentiation ability of rPEDF was confirmed by upregulation of several osteoblastic markers after treatment of a pre-osteoblastic cell line (UMR 201). Furthermore, both cell lines displayed increased mineralised nodule formation after administration. In vivo, PEDF inhibited osteosarcoma growth and metastasis when overexpressed and in the recombinant form. In addition, anti-tumour activity was observed upon testing with shorter peptides of PEDF. Pharmacoevaluation of rPEDF demonstrated stability within media over several days, and no significant side effects in terms of wound healing.

From these results, PEDF demonstrates multi-modal anti-tumour activity via anti-proliferation, anti-angiogenesis, pro-differentiation and anti-metastasis. PEDF may be a promising therapeutic agent for the treatment of patients with osteosarcoma.

Introduction and Aims: Improved survival has motivated aggressive surgery with musculoskeletal tumors. Pelvic resection is challenging because of the constraints of adjacent vital anatomy, and the considerable impact on limb and visceral function. The aims of this study was to assess the functional, oncologic and surgical outcomes following resections of the bony pelvis.

Method: Between 1996 and 2003, 49 patients underwent tumor resections of the pelvic ring. The mean age was 43 (range 15–72) years. There were 44 primary (36 bone, nine soft tissue) and five secondary tumors. Of the bone tumors, there were six osteosarcomas, five Ewings sarcomas, 12 chondrosarcomas and 13 others. Of the soft tissue tumors, nine were of neural origin. Tumor locations included the ilium, periacetabulum, pubic bones, sacrum or combinations of these. Neoadjuvant chemotherapy (seven patients) and pre-operative radiotherapy (eight patients) were also used. Function was assessed using the American Musculoskeletal Tumor Society Functional scoring system. No patient had metastases at presentation.

Results: Surgery – There were 40 limb sparing resections and nine hindquarter amputations. The surgical margins were intralesional (four), marginal (12), wide (28) and radical (five). Of the limb sparing surgery, prosthetic reconstructions were used in nine patients, biologic reconstructions in seven patients a combination of biologic and prosthetic reconstructions in three cases and no reconstructions in the others. The mean operating time was five (range 1.5–10) hours. The mean intra-operative blood loss was 10 (range 2–26) units. The average length of stay was 22 (range 2–110) days. Fifty percent of patients developed acute complications. Survival – There was one intra-operative death. There were nine local recurrences and 16 metastases. Death from disease occurred at a mean time of 13 (range 1–51) months. Mean follow-up was 28 (range 1–90) months. Functional assessment – Hind quarter amputation and periacetabular resections had the worse functional outcome. These accounted for almost 40% of all cases. Surprisingly, patients with periacetabular resections had the best score for emotional acceptance.

Conclusion: Pelvic resections are complex, demanding and accompanied by a high complication rate. Surgery significantly affects functional outcome. Disease control is similar to limb tumors and medium to long-term survival is possible. Emotional acceptance of surgery in survivors was surprisingly high. Major pelvic resection for malignancy appears justifiable.