Foreign body reaction with granuloma following Achilles tendon reconstruction with the LARS ligament

Foreign Body Reaction Following Achilles Tendon Reconstruction With the Ligament Advanced Reconstructive System: Patient Outcomes and Clinical Course

The Ligament Advanced Reinforcement System (LARS) is a common choice for ligament reconstruction in the lower limb due to its good functional and quality of life (QoL)-related outcomes. It is commonly used for Achilles tendon repair following a rupture. While it facilitates tissue ingrowth and boasts good biocompatibility, we report on multiple cases whereby foreign body reactions have led to the growth of granulomas requiring surgical excision and Flexor Hallucis Longus (FHL) transfer. Following these cases, patients have been shown to have excellent functional and QoL-related outcomes using the Manchester Oxford Foot Questionnaire (MOX-FQ) and Foot and Ankle Ability Measure (FAAM). Surgeons should consider FHL transfer as an alternative in patients undergoing Achilles tendon repair and be aware of the risk of foreign body reactions and the impact on ankle function and QoL post-operatively.

The efficacy and medium-term outcomes of ligament advanced reinforcement system compared with auto-grafts in anterior cruciate ligament reconstruction: At least 2 years follow-up

Background: Graft choice is an important step in the pre-operative plan of anterior cruciate ligament reconstruction (ACLR). The four-strand hamstring tendon (4SHT) is the most widely used auto-graft, while the Ligament Advanced Reinforcement System (LARS) is the newest typical biomaterial for ACLR. The physical activity level (PAL) before injury can affect the efficacy and outcomes of ACLR. This study aims to compare the efficacy and functional outcomes between ACLR using LARS and 4SHT in patients different PALs.

Methods: This was a prospective paired case-control study. ACL rupture patients included from 1 January 2017 to 31 December 2019 were subsequently divided into the high and plain PAL groups, according to their baseline PAL before injury. Clinical assessments included: Lachman test, pivot shift test, ligament laxity, Lysholm and International Knee Documentation Committee (IKDC) scores, and rate of returning to sports. The minimum follow-up was 2 years (y).

Results: A total of 58 patients had accomplished the 2 y follow-up (missing rate: 6.5%). In the high PAL group (n = 22), the positive rate of A–P laxity of the LARS subgroup was lower than the 4SHG subgroup (p = 0.138), while the Lysholm score (p = 0.002), IKDC score (p = 0.043), and rate of returning to sports (p = 0.010) of the LARS were higher than the 4SHG at 1 year follow-up; the positive rates of A–P laxity (p = 0.009) and pivot test (p = 0.027) were lower in the LARS than the 4SHG at 2 y follow-up. In the plain PAL group (n = 36), the positive rate of A–P laxity in the LARS subgroup was lower than the 4SHG at 1 year follow-up (p = 0.017); the positive rates of A–P laxity (p = 0.001), Lachman (p = 0.034), and pivot tests (p = 0.034) in the LARS were also lower than the 4SHG at 2 y follow-up, but the IKDC score (p = 0.038) and rate of returning to sports (p = 0.019) in the 4SHG were higher than the LARS.

Conclusion: In patients with high PAL, LARS can acquire better knee stability, sooner functional recovery, and returning to sports than 4SHG, while in patients without high PAL, 4SHG acquires better functional outcomes and a higher rate of returning to sports.

Biofabrication and Signaling Strategies for Tendon/Ligament Interfacial Tissue Engineering

Tendons and ligaments (TL) have poor healing capability, and for serious injuries like tears or ruptures, surgical intervention employing autografts or allografts is usually required. Current tissue replacements are nonideal and can lead to future problems such as high retear rates, poor tissue integration, or heterotopic ossification. Alternatively, tissue engineering strategies are being pursued using biodegradable scaffolds. As tendons connect muscle and bone and ligaments attach bones, the interface of TL with other tissues represent complex structures, and this intricacy must be considered in tissue engineered approaches. In this paper, we review recent biofabrication and signaling strategies for biodegradable polymeric scaffolds for TL interfacial tissue engineering. First, we discuss biodegradable polymeric scaffolds based on the fabrication techniques as well as the target tissue application. Next, we consider the effect of signaling factors, including cell culture, growth factors, and biophysical stimulation. Then, we discuss human clinical studies on TL tissue healing using commercial synthetic scaffolds that have occurred over the past decade. Finally, we highlight the challenges and future directions for biodegradable scaffolds in the field of TL and interface tissue engineering.

Effect of norbixin-based poly(hydroxybutyrate) membranes on the tendon repair process after tenotomy in rats

Purpose:

To determine the efficacy of norbixin-based poly(hydroxybutyrate) (PHB) membranes for Achilles tendon repair.

Methods:

Thirty rats were submitted to total tenotomy surgery of the right Achilles tendon and divided into two groups (control and membrane; n = 15 each), which were further subdivided into three subgroups (days 7, 14, and 21; n = 5 each). Samples were analyzed histologically.

Results:

Histological analysis showed a significant reduction in inflammatory infiltrates on days 7, 14 (p < 0.0001 for both), and 21 (p = 0.0004) in the membrane group compared to that in the control group. There was also a significant decrease in the number of fibroblasts in the control group on days 7, 14 (p < 0.0001), and 21 (p = 0.0032). Further, an increase in type I collagen deposition was observed in the membrane group compared to that in the control group on days 7 (p = 0.0133) and 14 (p = 0.0107).

Conclusion:

Treatment with norbixin-based PHB membranes reduces the inflammatory response, increases fibroblast proliferation, and improves collagen production in the tendon repair region, especially between days 7 and 14.