Excessive Derotational K-Wire Angulation Decreases Compression by Headless Compression Screw

Background Scaphoid fracture is the most common carpal bone fracture. Open reduction internal fixation of scaphoid fractures typically undergo stabilization by a single headless compression screw (HCS). During screw insertion, a derotational Kirschner wire (K-wire) is often placed for rotational control of the near and far fragment. Questions/purposes The aim of this study was to determine if there is an angle of derotational K-wire placement in relation to the axis of a HCS that compromises the amount of compression generated at a fracture site by the HCS. We hypothesize that increased off-axis angle will lead to decreased compression across the fracture site. Methods A Cellular Block 20 rigid polyurethane foam (Sawbones, Vashon, WA) scaphoid model was created to eliminate variability in bone mineral density in cadaveric bone. MiniAcutrak HCS screws (Acumed, Hillsboro, OR) were used for testing. Three conditions were tested: (1) HCS with derotational wire inserted parallel to the HCS (zero degrees off-axis); (2) HCS with derotational wire inserted 10 degrees off-axis; and (3) HCS with derotational wire inserted 20 degrees off-axis. Results A statistically significant difference in the mean compression of the control group (56.9 N) was found between the mean compression with the derotational K-wire placed 20 degrees off-axis (15.2 N) (p = 0.001). Conclusions Compression at the fracture site could be impeded by placing an excessively angulated off-axis derotation wire prior to insertion of the HCS. Clinical Relevance Our study adds a new detail to the optimal technique of HCS placement in scaphoid fractures to improve compression and fracture union.

Compression Screw Fixation of Lunate Fracture: Case Report and Review of the Literature

Background Isolated traumatic lunate fractures without other surgical carpal bone or ligamentous injuries are extremely rare, with few published reports available to guide management. Lunate fracture management is controversial, and depends on concurrent injuries of adjacent carpal bones, ligaments, risk of ischemia, and displacement. Case Description A 48-year-old right hand dominant man suffered a crush injury to the left hand caught between a forklift and a metal shelf. Radiographs and computed tomography imaging of the left hand and wrist were significant for a displaced Teisen IV fracture of the lunate. A dorsal ligament sparing approach was utilized to access, reduce, and fixate the fracture using a headless compression screw. After immobilization and rehab, at 9 months after initial injury, the patient was back to work on full duty without restriction and pleased with the results of his treatment. Literature Review A literature review of lunate fracture compression screw fixation was performed and revealed a total of three reports indicating successful treatment of fractures, with patients returning to full activity. Clinical Relevance Lunate fractures are rare, often missed, and treating these injuries can be challenging, particularly in the setting of acute trauma. Based on our limited experience, we believe that open reduction and internal fixation of isolated Teisen IV lunate fractures with a headless compression screw is a viable treatment modality with satisfactory outcomes.

Comminuted Trapezium Fracture: Case Presentation and Review of Surgical Fixation Techniques

We report a case of a 28-year-old male who sustained a comminuted trapezium fracture with carpometacarpal subluxation of the right hand. Treatment with internal fixation with a headless compression screw resulted in excellent outcomes.

Biomechanical comparison of intramedullary screw fixation, dorsal plating and K-wire fixation for stable metacarpal shaft fractures

We compared four methods of metacarpal shaft fixation: 2.2 mm intramedullary headless compression screw; 3.0 mm intramedullary headless compression screw; intramedullary K-wire fixation; and dorsal plate fixation. Transverse mid-diaphyseal fractures were created in 64 metacarpal sawbones and were assigned into four groups. Peak load to failure and stiffness were measured in cantilever bending and torsion. We found that dorsal plating had the highest peak load to failure. However, initial bending stiffness of the 3.0 mm intramedullary headless compression screw was higher than that of the dorsal plates. In torsion testing, dorsal plating had the highest peak torque, but there was no significant difference in torsional stiffness between the plate and intramedullary headless compression screw constructs. We concluded that intramedullary headless compression screw fixation is biomechanically superior to K-wires in cantilever bending and torsion; however, it is less stable than dorsal plating. In our study, the initial stability provided by K-wire fixation was sufficient to cope with expected loads in the early rehabilitation period, whereas dorsal plates and IHCS constructs provided stability far in excess of what is required.

Headless Compression Screw Fixation of Delayed Union Jones Fractures: A Case Series

Background. Different methods have been adopted to treat delayed union and non-union of fractures of the base of the fifth metatarsal using screws, plates and tension band wires. There has been increasing use of intramedullary screw fixation to treat these fractures with variable rates of success. The optimum screw diameter and properties have been a subject of debate. To assess the results of using a larger diameter 5.5 mm cannulated, headless variable-pitch screw to fix delayed union of Jones fracture of the base of the fifth metatarsal. Methods and methods. A case series study including 24 patients with delayed union of Jones fifth meta­tar­sal fractures. The fractures were fixed by a 5.5 mm cannulated variable-pitch compression titanium screw (Acumed® Acutrak 2® Screw System). Results. Radiological union was achieved in all patients at a mean of 7.2 weeks. At 12 months’ follow up, patients had a mean American Orthopedic Foot & Ankle Society midfoot score of 95.6. The mean Short Form 12 Physical and mental survey scores improved from 22.71 and 29.31 points preoperatively to 57.88 and 59.54 respectively. Conclusion.The headless compression screw achieved a satisfactory union rate for delayed union Lawren­ce zone II fractures of the base of the fifth metatarsal with satisfactory functional results.

Effect of oblique headless compression screw fixation for metacarpal shaft fracture: a biomechanical in vitro study

Background Metacarpal shaft fracture is a common fracture in hand trauma injuries. Surgical intervention is indicated when fractures are unstable or involve considerable displacement. Current fixation options include Kirschner wire, bone plates, and intramedullary headless screws. Common complications include joint stiffness, tendon irritation, implant loosening, and cartilage damage. Objective We propose a modified fixation approach using headless compression screws to treat transverse or short-oblique metacarpal shaft fracture. Materials and methods We used a saw blade to model transverse metacarpal neck fractures in 28 fresh porcine metacarpals, which were then treated with the following four fixation methods: (1) locked plate with five locked bicortical screws (LP group), (2) regular plate with five bicortical screws (RP group), (3) two Kirschner wires (K group), and (4) a headless compression screw (HC group). In the HC group, we proposed a novel fixation model in which the screw trajectory was oblique to the long axis of the metacarpal bone. The entry point of the screw was in the dorsum of the metacarpal neck, and the exit point was in the volar cortex of the supracondylar region; thus, the screw did not damage the articular cartilage. The specimens were tested using a modified three-point bending test on a material testing system. The maximum fracture forces and stiffness values of the four fixation types were determined by observing the force–displacement curves. Finally, the Kruskal–Wallis test was adopted to process the data, and the exact Wilcoxon rank sum test with Bonferroni adjustment was performed to conduct paired comparisons among the groups. Results The maximum fracture forces (median ± interquartile range [IQR]) of the LP, RP, HC, and K groups were 173.0 ± 81.0, 156.0 ± 117.9, 60.4 ± 21.0, and 51.8 ± 60.7 N, respectively. In addition, the stiffness values (median ± IQR) of the LP, HC, RP, and K groups were 29.6 ± 3.0, 23.1 ± 5.2, 22.6 ± 2.8, and 14.7 ± 5.6 N/mm, respectively. Conclusion Headless compression screw fixation provides fixation strength similar to locked and regular plates for the fixation of metacarpal shaft fractures. The headless screw was inserted obliquely to the long axis of the metacarpal bone. The entry point of the screw was in the dorsum of the metacarpal neck, and the exit point was in the volar cortex of the supracondylar region; therefore the articular cartilage iatrogenic injury can be avoidable. This modified fixation method may prevent tendon irritation and joint cartilage violation caused by plating and intramedullary headless screw fixation.

Single Versus Dual Headless Compression Screw Fixation of Scaphoid Nonunions: A Biomechanical Comparison

Background: Management of scaphoid nonunions with bone loss varies substantially. Commonly, internal fixation consists of a single headless compression screw. Recently, some authors have reported on the theoretical benefits of dual-screw fixation. We hypothesized that using 2 headless compression screws would impart improved stiffness over a single-screw construct. Methods: Using a cadaveric model, we compared biomechanical characteristics of a single tapered 3.5- to 3.6-mm headless compression screw with 2 tapered 2.5- to 2.8-mm headless compression screws in a scaphoid waist nonunion model. The primary outcome measurement was construct stiffness. Secondary outcome measurements included load at 1 and 2 mm of displacement, load to failure for each specimen, and qualitative assessment of mode of failure. Results: Stiffness during load to failure was not significantly different between single- and double-screw configurations ( P = .8). Load to failure demonstrated no statistically significant difference between single- and double-screw configurations. Using a qualitative assessment, the double-screw construct maintained rotational stability more than the single-screw construct ( P = .029). Conclusions: Single- and double-screw fixation constructs in a cadaveric scaphoid nonunion model demonstrate similar construct stiffness, load to failure, and load to 1- and 2-mm displacement. Modes of failure may differ between constructs and represent an area for further study. The theoretical benefit of dual-screw fixation should be weighed against the morphologic limitations to placing 2 screws in a scaphoid nonunion.

Volar Plating versus Headless Compression Screw Fixation of Scaphoid Nonunions: A Meta-analysis of Outcomes

Background Headless compression screw fixation with bone grafting has been the mainstay of treatment for scaphoid nonunion for the past several decades. Recently, locked volar plate fixation has gained popularity as a technique for scaphoid fixation, especially for recalcitrant or secondary nonunions. Purpose The purpose of this meta-analysis was to compare union rates and clinical outcomes between locked volar plate fixation and headless compression screw fixation for the treatment of scaphoid nonunions. Methods A literature search was performed for studies documenting treatment outcomes for scaphoid nonunions from 2000 to 2020. Inclusion criteria consisted of (1) average age > 18 years, (2) primary study using screw fixation, plate fixation, or both, with discrete data reported for each procedure, and (3) average follow-up of at least 3 months. Exclusion criteria consisted of studies with incomplete or missing data on union rates. Data from each study was weighted, combined within treatment groups, and compared across treatment groups using a generalized linear model or binomial distribution. Results Following title and full-text review, 23 articles were included for analysis. Preoperatively, patients treated with plate fixation had significantly longer time from injury to surgery and were more likely to have failed prior surgical intervention. There was no significant difference between union rates at 92 and 94% for screw and plate fixation, respectively. However, plate fixation resulted in longer time to union and lower modified Mayo wrist scores. Conclusion Patients treated with locked volar plate fixation were more likely to be used for recalcitrant or secondary nonunions. There was no statistically significant difference in union rates between screw and plate fixation. The results from this meta-analysis support the select use of locked volar plate fixation for scaphoid nonunion, especially recalcitrant nonunions and those that have failed prior surgical repair.

Comparison of Bending Strength among Plate, Steinmann Pin, and Headless Compression Screw Fixations for Proximal Ulnar Shaft Fracture in Sawbones

Purpose: Although plate osteosynthesis is commonly used to treat proximal ulna fracture, its treatment method is controversial because of complications such as large incision, long operation time, and soft tissue injury. Therefore, intramedullary headless compression screw (HCS) and Steinmann pin are considered as alternative treatment options. In this study, we aim to compare bending strength of plate and cortical screws, HCS, and Steinmann pin for proximal ulnar shaft fracture with sawbone. Methods: Transverse type fractures were made intentionally at the distal 7 cm from the proximal end of ulna sawbones and fixated with plate, HCS, and Steinmann pin after reduction. Three-point bending tests were performed with total of 21 sawbones, seven pieces for each group. Results: Average ultimate bending strength for each group was as follows; 521.7N for plate fixation group, 706.4N for HCS fixation group, and 812.6N for Steinmann pin fixation group. Statistically significant results were observed among the three groups (p<0.01). When two groups were compared separately, Steinmann pin fixation and plate fixation (p<0.01), Steinmann pin and HCS fixation (p=0.047) showed statistical significance. There was a significant trend between HCS and plate fixation group (p=0.064).Conclusion: HCS and Steinmann pin fixation showed higher bending strength when compared to plate fixation for proximal ulnar shaft fracture in sawbone. Although further studies are needed, HCS and Steinmann pin fixation are promising fixation methods that may be used as an alternative to plate fixation.

Intramedullary compression screw fixation of metacarpal and phalangeal fractures

The intramedullary headless compression screw (IMCS) technique represents a reliable alternative to percutaneous Kirschner-wire and plate fixation with minimal complications. Transverse fractures of the metacarpal shaft represent a good indication for this technique. Non-comminuted subcapital and short oblique fractures can also be treated with IMCS. This technique should not be used in the presence of an open epiphysis, infection and, most of all, in subchondral fractures, because of the lack of purchase for the head of the screw. A double screw construct is recommended for comminuted subcapital fractures of the metacarpal to avoid metacarpal shortening. IMCS can even be applied for peri-articular fractures of the proximal third of the phalanx and in some multi-fragmentary proximal and middle phalangeal fractures. Usually the intramedullary screws are not removed. The main indications for screw removal are joint protrusion, infection and screw breakage after new fracture. Cite this article: EFORT Open Rev 2020;5:624-629. DOI: 10.1302/2058-5241.5.190068