The Intraoperative Dilemma in Metacarpal Plate Fixation

Hand surgeons frequently encounter compromised cortical bone purchase during open reduction and internal fixation. When treating complex hand injuries, metacarpal plate fixation serves as an essential method to restore skeletal length, alignment, and rotation. However, overtightening a nonlocking cortical screw can instantly strip the delicate bone threads. This common intraoperative complication immediately confronts the surgeon with a difficult clinical choice. Specifically, one must decide whether to leave the loose screw in place or remove it entirely. Retaining the stripped screw might seem to maintain construct mass and fill the plate hole. Conversely, leaving a loose screw introduces serious risks of hardware migration and soft tissue irritation. On the other hand, removing the screw leaves an empty hole in both the plate and the underlying cortex. Many surgeons worry that an unfilled screw hole decreases overall construct stiffness or generates a mechanical stress riser. Historically, subjective habit guided this decision because rigorous biomechanical evidence was lacking. Consequently, trauma specialists needed clear experimental data to guide hardware management during bridge plating procedures.

Biomechanical Concerns: Retaining Versus Removing Hardware

Orthopedic specialists frequently worry that extracting stripped hardware compromises stability in comminuted shaft fractures. Therefore, clinicians often hesitate to remove loose screws during bridge plate osteosynthesis. In bridge plating, the implant acts as an extramedullary splint across the comminuted zone without compressing individual bone fragments. Because construct stability relies entirely on solid screw fixation in the proximal and distal bone segments, every screw feels critical. Practitioners worry that omitting hardware creates premature construct instability under early rehabilitation forces. Furthermore, leaving an empty screw hole adjacent to the fracture zone might concentrate local stresses, thereby causing secondary cortical failure. Alternatively, retaining a stripped screw poses recognized postoperative hazards. A loose nonlocking screw easily backs out during repetitive finger motion. Subsequently, protruding screw heads can produce extensor tendon impingement, tenosynovitis, or tendon rupture. In severe cases, migrating screws necessitate secondary surgical procedures for hardware removal and tenolysis. Consequently, surgeons often debate whether revision techniques or simple screw omission represents the superior operative strategy. Therefore, quantifying the true biomechanical effect of an empty hole versus a loose screw provides invaluable surgical guidance.

Cadaveric Study Design and Biomechanical Testing Protocols

To resolve this technical dilemma, researchers executed a rigorous biomechanical evaluation using sixty-four human cadaveric metacarpals. The team established comminuted diaphyseal fracture models and stabilized them in bridge mode using nonlocking screws. During plate application, investigators deliberately overtightened and stripped a single screw to simulate intraoperative thread failure. Subsequently, the team assigned specimens to two comparative arms: one cohort retained the loose screw, whereas the other had the screw completely extracted. Furthermore, investigators divided each group into cantilever bending and torsional loading protocols to replicate physiological hand forces. Cantilever bending simulated perpendicular dorsal forces that occur during routine manual grasp. Meanwhile, torsional testing applied continuous rotational torque to simulate twisting movements encountered during daily hand activities. The biomechanical testing apparatus recorded load displacement curves, construct stiffness, structural torque, and clinical failure points. Additionally, multivariable linear regression models evaluated the association between screw status and structural strength, while Fisher exact tests analyzed specific failure modes. This methodical setup enabled an objective comparison of primary stability under realistic physiologic biomechanical stresses.

Bending and Torsional Resistance: Identical Mechanical Performance

The biomechanical results revealed striking mechanical equivalence between constructs with retained screws and those with removed screws. Specifically, during cantilever bending at two millimeters of displacement, the retained screw group sustained an average load of 7.6 N. In comparison, the removed screw group tolerated an average load of 8.0 N. Multivariable statistical analysis confirmed that this difference lacked statistical significance. Similarly, torsional testing demonstrated virtually identical performance between the two cohorts. At ten degrees of rotational displacement, the retained group achieved a mean torque of 0.363 N m, whereas the removed group registered 0.370 N m. Moreover, the investigators found no significant differences in structural stiffness or stress levels between both conditions. Notably, critical differences emerged when analyzing failure patterns under extreme torsional stress. All specimens in cantilever bending failed through plate bending rather than bone breakage. However, during torsional overload beyond clinical limits, six of sixteen specimens with retained loose screws sustained secondary fractures propagating through the loose screw hole.

Evidence-Based Surgical Takeaways for Metacarpal Plating

These laboratory findings offer straightforward, actionable guidance for hand and orthopedic surgeons managing metacarpal fractures. Crucially, the evidence dispels the common concern that an empty screw hole acts as a dangerous stress riser under physiological forces. Removing a stripped nonlocking screw does not compromise bending strength or torsional resistance in bridge-plated comminuted metacarpals. Conversely, retaining a loose screw provides zero biomechanical benefit while creating substantial clinical liabilities. Under excessive torsional rotation, a retained loose screw actually concentrates local stresses, triggering secondary bone fractures. Furthermore, leaving loose hardware inside the hand increases the likelihood of postoperative screw migration. Protruding screw heads can irritate gliding extensor tendons, causing pain and requiring secondary surgery. Therefore, when a nonlocking cortical screw strips during metacarpal bridge plate fixation, surgeons can safely remove it without replacing it. This simple choice eliminates migration risks, protects adjacent soft tissues, and maintains the biomechanical integrity necessary for early functional rehabilitation.

Frequently Asked Questions

Why does removing a stripped screw not weaken bridge plate fixation?

Removing a stripped nonlocking screw does not weaken bridge plate fixation because stripped threads provide negligible holding purchase against physiological loads. In bridge mode constructs, overall mechanical stability depends primarily on plate geometry, working length, and solid bicortical screw purchase in the main distal and proximal bone segments. Therefore, an empty screw hole adjacent to comminuted bone retains comparable cantilever bending and torsional stiffness without reducing construct strength.

Can an empty plate hole create a structural stress riser in metacarpal bone?

Biomechanical testing shows that an empty screw hole does not create a clinically meaningful stress riser under standard physiological bending and torsional loads. In contrast, retaining a loose screw may actually induce focal stress concentrations under severe rotational displacement. Cadaveric data demonstrated that secondary fractures occurred around retained loose screw holes during extreme torsion, whereas empty hole configurations resisted torsional deformation without localized bone fracturing.

What complications occur if a loose metacarpal screw is left in place?

Retaining a loose metacarpal screw substantially elevates the risk of postoperative hardware migration and clinical complications. As patients participate in early active finger mobilization, unsecured screws frequently back out beneath the thin dorsal soft tissue envelope. Consequently, protruding screw heads cause extensor tendon impingement, painful tenosynovitis, or tendon rupture. These preventable soft tissue complications often necessitate secondary revision surgery for hardware extraction and tendon debridement.

Disclaimer: This content is for informational and educational purposes only and should not be considered medical advice. Always consult a qualified healthcare professional regarding clinical decisions, diagnosis, or treatment plans. Refer to the latest local and national guidelines for clinical practice.

References

1. Chung CCY et al. Loose Screw or No Screw? A Biomechanical Study to Answer a Common Intraoperative Dilemma. Hand (N Y). 2026 Oct 30. doi: 10.1177/15589447261496536. PMID: 42959000.


2. Curtis BD, Fajardo M, Lattanza LL. A Biomechanical Comparison of Fixation Techniques in Metacarpal Shaft Fractures. Clin Orthop Relat Res. 2015;473(11):3420-3426.


3. Yao J, Barr C, Behn A. Biomechanical analysis of locking plates for fixation of metacarpal shaft fractures. J Hand Surg Am. 2014;39(12):2437-2443.