Plantar Pressure Anomalies After Open Reduction With Internal Fixation of High-Grade Calcaneal Fractures.
BACKGROUND
Plantar pressure abnormalities after open reduction with internal fixation (ORIF) of intra-articular calcaneal fractures have been observed previously, but high-grade fractures were not selectively investigated and follow-up times were shorter than 2 years. The purpose of this study was to characterize plantar pressure anomalies in patients with exclusively high-grade calcaneal fractures after ORIF with a minimum 2 years of follow-up, and to test the association between plantar pressure distribution and the clinical outcome.


METHODS
The orthopaedic registry was reviewed to identify patients with isolated high-grade calcaneal fractures (Sanders types III-IV) who were operated on and had a minimum 2 years of follow-up. Sixteen patients were evaluated. Mean age was 47 years and follow-up was between 2 and 6 years. The Pedar-Mobile system was used to measure 3 loading and 3 temporal variables and compare these between the operated and the uninjured limbs.


RESULTS
Mean American Orthopaedic Foot and Ankle Society (AOFAS) score was 76 ± 7 at latest follow-up. Bohler's angle was 5 ± 8 degrees before surgery and 25 ± 7 degrees at latest follow-up. Stance was shorter in operated limbs (P = .001). Timing of the peak of pressure was delayed in operated limbs under the hallux and the second toe (P ≤ .03). Peak pressure, force time integral, and pressure time integral were increased under the lateral midfoot (P ≤ .03) and decreased under the second metatarsal (P ≤ .03). Force time integral was decreased under the first metatarsal (P = .02) and under the hallux and the lateral toes (P ≤ .05). Increased loading under the lateral midfoot and decreased loading under the lateral toes were correlated with poorer clinical outcome (r = -.53, P < .05, and r = .63, P < .01, respectively).


CONCLUSIONS
Side-to-side plantar pressure mismatch persisted at more than 2 years after ORIF of high-grade calcaneal fractures performed via lateral approach, despite improvement of Bohler's angle. This was characterized by shortened stance phase, delayed timing of peak of pressure under the hallux and second toe, lateral load shift at the midfoot, and decreased toe pressures in operated limbs. Since loading abnormalities were correlated with the clinical outcome, modifications in treatment strategy that can improve foot loading may be desirable in these cases.


METHODS
Level III, case control.
Department of Orthopedic Surgery, Meir General Hospital, Kfar Saba, Israel Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel iftachhetsroni@gmail.com.
Iftach
I
Hetsroni
Biomechanics Laboratory, Zinman College of Physical Education and Sport Sciences, Wingate Institute, Netanya, Israel.
David
D
Ben-Sira
Department of Orthopedic Surgery, Meir General Hospital, Kfar Saba, Israel Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Meir
M
Nyska
Biomechanics Laboratory, Zinman College of Physical Education and Sport Sciences, Wingate Institute, Netanya, Israel.
Moshe
M
Ayalon
D000293:Adolescent; D000328:Adult; D000368:Aged; D002111:Calcaneus / Q000293:injuries / Q000601:surgery*; D005260:Female; D018409:Foot Injuries / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000379:methods*; D050723:Fractures, Bone / Q000601:surgery*; D006801:Humans; D057072:Intra-Articular Fractures / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011312:Pressure; D016896:Treatment Outcome
Bohler’s angle; calcaneal fracture; loading variables; plantar pressure; temporal variables