Treatment of scaphoid fractures and pseudarthroses with the human allogeneic cortical bone screw. A multicentric retrospective study

Abstract

Background Allograft bone screws are rarely described for the fixation of the scaphoid. When fresh fractures are treated, metal screws are mainly used; when pseudarthrosis is the indication, plates in combination with vascularized or non-vascularized bone grafts are mainly used. The necessity of metallic screw removal is under debate, but it is mandatory for plates because of movement restrictions due to the plate. The use of biomaterials in scaphoid fracture fixation was described as leading to union rates of between 64 and 100%. Brcic showed the incorporation of an allogeneic cortical bone screw at 10 weeks postoperative, along with revascularization and stable osteosynthesis with primary bone healing, without any signs of immunological rejection. The purpose of this retrospective study was to explore the results obtained using an allogenic cortical bone screw (Shark Screw®) in patients with fresh scaphoid fracture fixation and pseudarthroses with respect to union rates and time to union. Patients and methods We retrospectively analyzed 75 patients: 31 with fresh fractures and 44 pseudarthrosis patients. The Shark Screw® was used for the fixation of the scaphoid in the fresh-fracture and pseudarthrosis patients. We evaluated the union rate, complication rate and time to union. Results Using the human allogeneic cortical bone screw for scaphoid fracture fixation led to a high union rate (94–96%). There were two nonunions in the fresh fracture group and two nonunions in the pseudarthrosis group. The complication rate was 1.3% (1 patient). Median time to union was 16, 18 and 29 weeks for the fresh-fracture, pseudarthrosis and delayed-union patients, respectively. The treatment of fresh scaphoid fractures and pseudarthroses showed similar union rates to those described in the literature, uses a shorter and less invasive surgical method with no need for hardware removal, and has a low complication rate. Conclusion Using the human allogenic cortical bone screw (Shark Screw®) led to similar union rates in fresh fractures—but better union rates in pseudarthrosis patients—compared to those presented in the literature for other scaphoid fracture fixation techniques, and it enabled a short and low-invasive procedure without any donor site morbidity and without the necessity to remove the hardware in a second surgery. The pseudarthrosis patient group showed a particularly strong benefit from this new procedure. The physiological bone metabolism remodels the cortical bone screw without scars. Level of evidence: III: retrospective cohort study, therapeutic investigation of a treatment.

Non-union Treatment in the arm, wrist, and fingers: A Multicenter Retrospective Study Contrasting Conventional Treatment with the Allogeneic Cortical Bone Screw (Shark Screw®)

“…Surgical procedures vary with location of the non-union. For using the cortical bone screw surgical procedures were described before for different locations [40] of the hand, for scaphoid fractures [42],…”

“…For the human allogeneic cortical bone screw this process was shown after 10 weeks [36]. Recent publications show that, when using the Shark Screw, the union rate is between 94-100% for fracture treatment, arthrodesis and non-union [40][41][42][43] and thus similar to union rates with conventional methods.…”

Non-Union Treatment in the Foot, Ankle, and Lower Leg: A Multicenter Retrospective Study Comparing Conventional Treatment with the Human Allogeneic Cortical Bone Screw (Shark Screw®)

“…The Shark Screw ® merges human cortical bone properties with screw stability, addressing non-union surgery principles by integrating mechanical and biological aspects [4,13,27]. The allogeneic cortical bone screw demonstrated consistent success in fracture and osteotomy fixation [31][32][33], primary arthrodesis [34,35], salvage arthrodesis [36], and non-union surgery [33], emphasizing its versatile utility across diverse orthopedic applications. A single construct delivers the essential elements required for bone healing, addressing both the mechanical and biological aspects of the healing process [1].…”