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A comparison between a hinged plate and screw system and a conventional tension-band plate and screw system used for correction of an angular deformity of the lower limb: an animal study.

Wu Z, Zhao D, Zhao L, Liu J, Li H, Zhu J, Ma F, Porter DE - J Orthop Surg Res (2015)

Bottom Line: The technique was compared with the use of a conventional tension-band plate and screw system.A P < 0.05 was statistical significant.No significant difference was found between the groups regarding the mean corrective rates of the angles (P < 0.05).

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatric Orthopaedics, Xin-Hua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, No. 1665, Kongjiang Road, Shanghai, 200092, China. w993167wmg@163.com.

ABSTRACT

Background: The purpose of the animal study is to introduce a newly designed hinged plate and screw system for correction of angular deformities of the lower limbs. The technique was compared with the use of a conventional tension-band plate and screw system.

Methods: This is a randomized controlled animal trial. Eight 3-month-old Bama miniature pigs were used to establish animal models. In each animal, one leg was randomly allocated into study group and another leg into control group. Legs of the study group were corrected with a hinged plate and screw system, and legs of the control group were corrected with a conventional tension-band plate and screw system. The corrective rates of medial slope angle, medial proximal tibial angle, and angle of the two arms of the hinged plate were measured. Residual stress on the implants was also evaluated. A P < 0.05 was statistical significant.

Results: At the final measurements of 18 weeks, the mean corrective rates of medial slope angle, medial proximal tibial angle, and angle of the two arms of the study group were 0.71°/week, 0.85°/week, and 2.18°/week, respectively; the data in the control group were 0.84°/week, 0.89°/week, and 2.13°/week, respectively. No significant difference was found between the groups regarding the mean corrective rates of the angles (P < 0.05). The mean residual stress in the study group was 643.35 MPa, and measurement in the control group was 1,273.63 MPa, with a significant difference (P < 0.05).

Conclusions: Compared to the conventional tension-band plate and screw system, the hinged plate and screw system may be more reliable for correction of angular deformities of the lower limb.

No MeSH data available.


Related in: MedlinePlus

Intraoperative photos. (A) A hinged plate and screw system is implanted. (B) No obvious prominence observed after wound closure.
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Fig3: Intraoperative photos. (A) A hinged plate and screw system is implanted. (B) No obvious prominence observed after wound closure.

Mentions: The animal was placed in the supine position on a radiolucent table. A 2–3-cm-long incision was made on the medial aspect of the proximal tibia (Figure 3). Dissection went deep to the tibia with preservation of the periosteum. In the mid-coronal plane, a 1-mm Keith needle was drilled into the physis. That procedure was performed under guidance of fluoroscope. A hinged plate (HP group, Shanghai Puwei Medical instrument Co., Ltd., Shanghai, China) was placed extra-periosteally and mounted over the needle to center it upon the physis. The cortex was predrilled with a 1.8-mm drill bit so as to reduce stress during screw insertion [3,4]. The screws should be placed parallel or slightly convergent (0° to 20°) without encroaching on the growth plate cartilage. The two screws were tightened alternately.Figure 3


A comparison between a hinged plate and screw system and a conventional tension-band plate and screw system used for correction of an angular deformity of the lower limb: an animal study.

Wu Z, Zhao D, Zhao L, Liu J, Li H, Zhu J, Ma F, Porter DE - J Orthop Surg Res (2015)

Intraoperative photos. (A) A hinged plate and screw system is implanted. (B) No obvious prominence observed after wound closure.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4419467&req=5

Fig3: Intraoperative photos. (A) A hinged plate and screw system is implanted. (B) No obvious prominence observed after wound closure.
Mentions: The animal was placed in the supine position on a radiolucent table. A 2–3-cm-long incision was made on the medial aspect of the proximal tibia (Figure 3). Dissection went deep to the tibia with preservation of the periosteum. In the mid-coronal plane, a 1-mm Keith needle was drilled into the physis. That procedure was performed under guidance of fluoroscope. A hinged plate (HP group, Shanghai Puwei Medical instrument Co., Ltd., Shanghai, China) was placed extra-periosteally and mounted over the needle to center it upon the physis. The cortex was predrilled with a 1.8-mm drill bit so as to reduce stress during screw insertion [3,4]. The screws should be placed parallel or slightly convergent (0° to 20°) without encroaching on the growth plate cartilage. The two screws were tightened alternately.Figure 3

Bottom Line: The technique was compared with the use of a conventional tension-band plate and screw system.A P < 0.05 was statistical significant.No significant difference was found between the groups regarding the mean corrective rates of the angles (P < 0.05).

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatric Orthopaedics, Xin-Hua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, No. 1665, Kongjiang Road, Shanghai, 200092, China. w993167wmg@163.com.

ABSTRACT

Background: The purpose of the animal study is to introduce a newly designed hinged plate and screw system for correction of angular deformities of the lower limbs. The technique was compared with the use of a conventional tension-band plate and screw system.

Methods: This is a randomized controlled animal trial. Eight 3-month-old Bama miniature pigs were used to establish animal models. In each animal, one leg was randomly allocated into study group and another leg into control group. Legs of the study group were corrected with a hinged plate and screw system, and legs of the control group were corrected with a conventional tension-band plate and screw system. The corrective rates of medial slope angle, medial proximal tibial angle, and angle of the two arms of the hinged plate were measured. Residual stress on the implants was also evaluated. A P < 0.05 was statistical significant.

Results: At the final measurements of 18 weeks, the mean corrective rates of medial slope angle, medial proximal tibial angle, and angle of the two arms of the study group were 0.71°/week, 0.85°/week, and 2.18°/week, respectively; the data in the control group were 0.84°/week, 0.89°/week, and 2.13°/week, respectively. No significant difference was found between the groups regarding the mean corrective rates of the angles (P < 0.05). The mean residual stress in the study group was 643.35 MPa, and measurement in the control group was 1,273.63 MPa, with a significant difference (P < 0.05).

Conclusions: Compared to the conventional tension-band plate and screw system, the hinged plate and screw system may be more reliable for correction of angular deformities of the lower limb.

No MeSH data available.


Related in: MedlinePlus