Comparison of 3 Dynamic External Fixation Devices for Proximal Interphalangeal Joint Dorsal Fracture-Dislocations in a Cadaver Model.
Comparison of 3 Dynamic External Fixation Devices for Proximal Interphalangeal Joint Dorsal Fracture-Dislocations in a Cadaver Model.
- 2023
CLINICAL RELEVANCE: This study informs surgeon decision-making when considering dynamic external fixator options for dorsal PIP joint fracture-dislocations. Copyright © 2022 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved. CONCLUSIONS: All 3 external fixators restored PIP joint stability following simulated dorsal fracture-dislocation, with all reductions maintained after motion testing. The syringe-pins construct had significantly greater median residual P2 dorsal displacement after the initial reduction and motion testing, which is of unclear clinical importance. METHODS: We tested 30 digits from 10 fresh-frozen, thawed cadaver hands. We aimed to remove the palmar 50% of the base of each digit's middle phalanx (P2), simulating an unstable dorsal PIP joint fracture-dislocation. Each PIP joint was then stabilized via external fixation with either a pins-and-rubber-bands construct, pins-only construct, or tuberculin syringe-pins construct. We allocated 10 digits per fixation group. The finger tendons were secured to a computer-controlled stepper motor-driven linear actuator. Via this mechanism, all PIP joints were taken through 1,400 cycles of flexion-extension. With the PIP joint in neutral extension, we measured the P2 dorsal translation at baseline, after fixator stabilization, and after the motion protocol. PURPOSE: Several improvised dynamic external fixation devices are used for treating unstable dorsal proximal interphalangeal (PIP) joint fracture-dislocations. We compared the effectiveness of 3 constructs for simulated dorsal PIP joint fracture-dislocations in a cadaver model. RESULTS: The actual mean P2 palmar defect created was 48% of the base. All PIP joints were unstable after creating the defect, with a mean initial P2 dorsal displacement of 3.7 mm. After application of the fixators, all PIP joint dislocations were reduced. The median residual P2 dorsal displacements were 0.0 mm for the pins-rubber bands group, 0.1 mm for the pins-only group, and 0.5 mm for the syringe-pins group. There were no cases of PIP joint redislocation after flexion-extension cycling, and the median dorsal P2 displacements were 0.0 mm for the pins-rubber bands group; 0.0 mm for the pins-only group; and 0.5 mm for the syringe-pins group.
English
0363-5023
10.1016/j.jhsa.2022.01.019 [doi] S0363-5023(22)00059-4 [pii]
*Finger Injuries
*Fracture Dislocation
*Fractures, Bone
*Joint Dislocations
Cadaver
External Fixators
Finger Injuries/su [Surgery]
Finger Joint/su [Surgery]
Fracture Dislocation/su [Surgery]
Fracture Fixation/mt [Methods]
Fractures, Bone/su [Surgery]
Humans
Joint Dislocations/su [Surgery]
Range of Motion, Articular
Curtis National Hand Center
MedStar Health Research Institute
Journal Article
CLINICAL RELEVANCE: This study informs surgeon decision-making when considering dynamic external fixator options for dorsal PIP joint fracture-dislocations. Copyright © 2022 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved. CONCLUSIONS: All 3 external fixators restored PIP joint stability following simulated dorsal fracture-dislocation, with all reductions maintained after motion testing. The syringe-pins construct had significantly greater median residual P2 dorsal displacement after the initial reduction and motion testing, which is of unclear clinical importance. METHODS: We tested 30 digits from 10 fresh-frozen, thawed cadaver hands. We aimed to remove the palmar 50% of the base of each digit's middle phalanx (P2), simulating an unstable dorsal PIP joint fracture-dislocation. Each PIP joint was then stabilized via external fixation with either a pins-and-rubber-bands construct, pins-only construct, or tuberculin syringe-pins construct. We allocated 10 digits per fixation group. The finger tendons were secured to a computer-controlled stepper motor-driven linear actuator. Via this mechanism, all PIP joints were taken through 1,400 cycles of flexion-extension. With the PIP joint in neutral extension, we measured the P2 dorsal translation at baseline, after fixator stabilization, and after the motion protocol. PURPOSE: Several improvised dynamic external fixation devices are used for treating unstable dorsal proximal interphalangeal (PIP) joint fracture-dislocations. We compared the effectiveness of 3 constructs for simulated dorsal PIP joint fracture-dislocations in a cadaver model. RESULTS: The actual mean P2 palmar defect created was 48% of the base. All PIP joints were unstable after creating the defect, with a mean initial P2 dorsal displacement of 3.7 mm. After application of the fixators, all PIP joint dislocations were reduced. The median residual P2 dorsal displacements were 0.0 mm for the pins-rubber bands group, 0.1 mm for the pins-only group, and 0.5 mm for the syringe-pins group. There were no cases of PIP joint redislocation after flexion-extension cycling, and the median dorsal P2 displacements were 0.0 mm for the pins-rubber bands group; 0.0 mm for the pins-only group; and 0.5 mm for the syringe-pins group.
English
0363-5023
10.1016/j.jhsa.2022.01.019 [doi] S0363-5023(22)00059-4 [pii]
*Finger Injuries
*Fracture Dislocation
*Fractures, Bone
*Joint Dislocations
Cadaver
External Fixators
Finger Injuries/su [Surgery]
Finger Joint/su [Surgery]
Fracture Dislocation/su [Surgery]
Fracture Fixation/mt [Methods]
Fractures, Bone/su [Surgery]
Humans
Joint Dislocations/su [Surgery]
Range of Motion, Articular
Curtis National Hand Center
MedStar Health Research Institute
Journal Article