A Prospective Study of Acute Undisplaced and Minimally Displaced Scaphoid Fractures Managed by Aggressive Conservative Approach

The Effect of Derotational Kirschner Wires on Fracture Gap Reduction With Variable-Pitch Headless Screws

PURPOSE

We evaluated the impact of angled derotational Kirschner wires (K-wires) on fracture gap reduction with variable-pitch headless screws.

METHODS

Fully threaded variable-pitch headless screws (20 and 28 mm) were inserted into "normal" bone models of polyurethane blocks. In separate trials, derotational K-wires were inserted at predetermined angles of 0°, 15°, 30°, and 40° and compared with each other, with no K-wire as a control. Fluoroscopic images taken after each screw turn were analyzed. The optimal fracture gap closure, initial screw push-off, and screw back-out gap creation were determined and compared at various derotational K-wire angles.

RESULTS

Initial screw push-off due to screw insertion and screw back-out gap creation were not significantly affected by the angle of the derotational K-wire. With a 20-mm screw, only a 40° derotational K-wire led to significantly less gap closure compared with control and with 0°, 15°, and 30° derotational K-wires. It led to an approximately 60% decrease in gap closure compared with no K-wire. With the 28-mm screw, compared with no K-wire, 15° and 30° derotational K-wires led to statistically significant decreases in gap closure (approximately 25%), whereas a 40° derotational K-wire led to an approximately 60% decrease. With the 28-mm screw, the 40° derotational K-wire also led to a statistically significant smaller gap closure when compared with 0°, 15°, and 30° derotational K-wires.

CONCLUSIONS

A derotational K-wire placed in parallel to the planned trajectory of a headless compression screw does not affect fracture gap closure. With greater angulation of the derotational K-wire, the fracture gap is still closed, but less tightly.

CLINICAL RELEVANCE

Derotational K-wires can help prevent fracture fragment rotation during headless compression screw insertion. At small deviations from parallel (≤30°), fracture gap closure achieved by the screw is minimally affected. At greater angles (ie, 40°), fracture gap closure may be substantially reduced, preventing fracture compression.

Surgical versus nonsurgical treatment for scaphoid waist fracture with slight or no displacement: A meta-analysis and systematic review

BACKGROUND

Surgical or nonsurgical treatment for scaphoid waist fracture with slight or no displacement is still controversial. This study compared the efficacy of the 2 methods through meta-analysis to provide a reference for the choice of clinical treatment options.

METHODS

Two individuals independently searched for relevant RCTs and cohort studies from PubMed (1946-February 2018), Embase (1946-February 2018), and Cochrane library (1997-February 2018). After quality assessment and data extraction, Stata 14 software was used for combining the effect size, testing heterogeneity, and studying bias. GRADEpro was used to rate the level of evidence.

RESULTS

Ten RCTs and 4 cohort studies with 765 patients were included. No statistical difference in satisfaction, pain, and Disability of the Arm, Shoulder, and Hand score was found after surgical and nonsurgical treatments. Compared with nonsurgical treatment, surgical treatment shortened the time to union (SMD = -5.01, 95% CI: -7.47 to -2.58, P = .000), decreased the convalescence (SMD = -2.09, 95% CI: -3.08 to -1.11, P = .000), and reduced the incidence of nonunion (RR = 0.47, 95% CI: 0.24-0.90), P = .023). Subgroup analyses showed that the percutaneous fixation treatment can shorten the time to union [SMD = -1.82, 95%CI (-2.22 to -1.42), P = = .000] and the convalescence (SMD = -4.26, 95%CI: -6.16 to -2.35, P = = .054), and open reduction fixation treatment can reduce the incidence of nonunion (RR = 0.20, 95%CI: 0.06-0.69, P = = .01).

CONCLUSION

For scaphoid waist fractures with slight or no displacement, there was no statistical difference in patient satisfaction, pain, and The Disability of the Arm, Shoulder, and Hand scores between surgical treatment and nonsurgical treatment. Closed surgical treatment can shorten the time to union and convalescence, and open reduction can reduce the incidence of nonunion. On the basis of this conclusion, chief physicians can consider which treatment to use according to the patient's clinical situation and their subjective intention.