On Aspects of Intra-Articular Ligament Reconstruction

Intra-articular ligament injuries are common in the younger and more active part of the population. These injuries often require surgical reconstruction to restore joint stability due to lack of healing potential. The success of a ligament reconstruction depends on several elements, including biological healing of musculoskeletal tissue. Graft incorporation by tendon to bone healing and the remodeling of the tendon, are crucial to restore and maintain joint stability following a ligament reconstruction. This project aimed to investigate aspects of tendon to bone healing and tendon graft augmentation in ligament reconstruction. Clinicals registry data and in vivo studies enabled evaluation of different timepoints in the healing and remodeling process of intra-articular ligament reconstructions. Local administration of bone anabolic reagents (GSK126 compared to BMP-2) were evaluated for their potentially enhancing effect on tendon to bone healing in an in vivo model. Our findings indicate that these agents have the potential to enhance tendon to bone tunnel healing in ligament reconstructions, although the results did not reflect significantly enhanced biomechanical outcomes or new bone formation. The use of a synthetic suture tape on its own, or as a tendon graft augmentation, in an early phase of intra-articular ligament reconstruction was investigated using an in vivo model in rabbits. This study demonstrated increased biomechanical properties in joints with suture tape, compared to tendon graft alone. In addition, as the suture tape did not negatively affect new bone formation in the bone tunnels or invoke prolonged inflammation, it appears to be safe for use in intra-articular reconstruction within the time frames of this study. Pre-clinical studies have demonstrated a negative effect of non-steroidal anti-inflammatory drugs (NSAIDs) on musculoskeletal tissue healing, such as tendon to bone healing. Data from the Norwegian Knee Ligament Registy were evaluated to assess the effect of NSAIDs on an intra-articular ligament reconstruction. Our analysis showed that limited peri-operative administration of NSAIDs to patients undergoing anterior cruciate ligament reconstruction does not reduce graft survival, or increase the risk for either revision or poor functional outcome

Closed reduction of dorsally displaced distal radius fractures in the elderly provided improved final radiographic results

Abstract Background Recent guidelines recommend non-operative treatment as primary treatment in elderly patients with displaced distal radius fractures. Most of these fractures are closely reduced. We aimed to evaluate the radiological results of closed reduction and casting of dorsally displaced distal radius fractures in patients 65 years or older. Methods A total of 290 patients treated during the years 2015, 2018 and 2019 in an urban outpatient fracture clinic with complete follow-up at least 5 weeks post-reduction were available for analysis. Closed fracture reduction was performed by manual traction under hematoma block. A circular plaster of Paris cast was used. Radiographs pre- and post-reduction and at final follow-up were analyzed. Results Mean age was 77 years (SD 8) and 258 (89%) were women. Dorsal tilt improved from mean 111° (range 83–139) to 89° (71–116) post-reduction and fell back to mean 98° (range 64–131) at final follow-up. Ulnar variance was 2 mm ((-1)-12) pre-reduction, 0 mm ((-3)-5) post-reduction and ended at mean 2 mm (0–8). Radial inclination went from 17° ((-6)-30) to 23° (SD 7–33), and then back to 18° (0–32) at final follow-up. 41 (14%) patients had worse alignment at final follow-up compared to pre-reduction. 48 (17%) obtained a position similar to the starting point, while 201 (69%) improved. Fractures with the volar cortex aligned after reduction retained 0.4 mm (95% Confidence Interval (CI) 0.1 to 0.7; p = 0,022) more radius length during immobilization. In a regression analysis, less ulnar variance in initial radiographs (OR 1.8 (95% CI 1.4 to 2.3) per mm, p < 0.001) and lower age (OR 1.06 (95% CI 1.02 to 1.09) per year, p < 0.003) protected against loss of reduction. Conclusion Subsequent loss of reduction after initial closed reduction was seen in most distal radius fractures. Reduction improved overall alignment in 2/3 of the patients at final follow-up. An aligned volar cortex seemed to protect partially against loss of radial length

Biomechanical comparison of tension band wiring and plate fixation with locking screws in transverse olecranon fractures

Background: Tension band wiring (TBW) is the standard method for treating transverse olecranon fractures, but high rates of complications and reoperations have been reported. Plate fixation (PF) with locking screws has been introduced as an alternative method that may retain the fracture reduction better with a higher load to failure. Methods: Twenty paired cadaveric elbows were used. All soft tissues except for the triceps tendon were removed. A standardized transverse fracture was created, and each pair was allocated randomly to TBW or PF with locking screws. The triceps tendon was mounted to the materials testing machine with the elbow in 90° of flexion. Construct stiffness was compared 3 times. Then, the elbows underwent a chair lift-off test by loading the triceps tendon to 300 N for 500 cycles. Finally, a load-to-failure test was performed, and failure mechanism was recorded. Results: The construct stiffness of PF was higher in the first of 3 measurements. No difference was observed in the cyclic test or in load to failure. Hardware failure was the failure mechanism in 8 of 10 TBW constructs, and all failures occurred directly under the twists of the metal wire. Hardware failure was the cause of failure in only 1 elbow in the PF group (P < .01). Conclusion: There was no difference in fracture displacement following fixation with TBW and PF with locking screws in transverse olecranon fractures. However, assessment of the mode of hardware failure identified the metal cerclage twist as the weakest link in the TBW construct

Negative effect of zoledronic acid on tendon-to-bone healing: In vivo study of biomechanics and bone remodeling in a rat model

Background and purpose: Outcome after ligament reconstruction or tendon repair depends on secure tendon-to-bone healing. Increased osteoclastic activity resulting in local bone loss may contribute to delayed healing of the tendon–bone interface. The objective of this study was to evaluate the effect of the bisphosphonate zoledronic acid (ZA) on tendon-to-bone healing. Methods: Wistar rats (n = 92) had their right Achilles tendon cut proximally, pulled through a bone tunnel in the distal tibia and sutured anteriorly. After 1 week animals were randomized to receive a single dose of ZA (0.1 mg/kg IV) or control. Healing was evaluated at 3 and 6 weeks by mechanical testing, dual-energy X-ray absorptiometry and histology including immunohistochemical staining of osteoclasts. Results: ZA treatment resulted in 19% (95% CI 5–33%) lower pullout strength and 43% (95% CI 14–72%) lower stiffness of the tendon–bone interface, compared with control (2-way ANOVA; p = 0.009, p = 0.007). Administration of ZA did not affect bone mineral density (BMD) or bone mineral content (BMC). Histological analyses did not reveal differences in callus formation or osteoclasts between the study groups. Interpretation: ZA reduced pullout strength and stiffness of the tendon–bone interface. The study does not provide support for ZA as adjuvant treatment in tendon-to-bone healing