Effects of non-weight-bearing on the immature femoral head following ischemic osteonecrosis: An experimental investigation in immature pigs

Harry K W Kim, Olumide Aruwajoye, Jeffrey Stetler, Alec Stall

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

Background: Local non-weight-bearing as a treatment for Legg-Calvé-Perthes disease remains controversial since a clear scientific basis for this treatment is lacking. The purpose of this study was to determine the effects of non-weight-bearing on decreasing the femoral head deformity following ischemic osteonecrosis and to investigate its biological effects. Methods: Unilateral femoral head ischemia was induced in sixteen piglets by placing a ligature around the femoral neck and transecting the ligamentum teres. Eight animals received a hind-limb amputation to prevent weight-bearing on the ischemic side (NWB group). The remaining eight piglets were allowed to bear weight as tolerated (WB group). The contralateral femoral heads of the WB group were used as normal controls. All animals were killed at eight weeks after induction of ischemia, when a deformity is expected in this model. Radiographic, microcomputed tomographic (micro-CT), and histomorphometric assessments were performed. Results: Radiographic and micro-CT assessments showed significantly greater flattening of the infarcted epiphysis in the WB group compared with the NWB group. Themean epiphyseal quotient (ratio of femoral head height to diameter) was significantly lower in the WB group (0.29 ± 0.06) compared with the NWB group (0.41 ± 0.06, p < 0.001). Histomorphometric analyses showed that themean percentage revascularization of the infarcted epiphysis was significantly greater in the NWB group (95% ± 14%) compared with the WB group (34% ± 33%, p < 0.0004), suggesting that revascularization was more rapid in the NWB group. Both histomorphometric and micro-CT analyses of trabecular bone parameters showed significantly decreased bone volume and decreased trabecular number in the infarcted epiphysis of the NWB group compared with theWB group (p < 0.05). Conclusions: Local non-weight-bearing decreased the deformity following ischemic femoral head osteonecrosis and increased the rates of revascularization and resorption of the infarcted epiphysis. Clinical Relevance: Local non-weight-bearing was mechanically protective but biologically suboptimal following ischemic osteonecrosis since it increased the imbalance of bone resorption and formation.

Original languageEnglish (US)
Pages (from-to)2228-2237
Number of pages10
JournalJournal of Bone and Joint Surgery - Series A
Volume94
Issue number24
DOIs
StatePublished - Dec 19 2012

Fingerprint

Epiphyses
Osteonecrosis
Thigh
Swine
Ischemia
Round Ligaments
Legg-Calve-Perthes Disease
Femur Neck
Weight-Bearing
Bone Resorption
Amputation
Osteogenesis
Ligation
Extremities
Weights and Measures
Bone and Bones
Therapeutics

ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine

Cite this

Effects of non-weight-bearing on the immature femoral head following ischemic osteonecrosis : An experimental investigation in immature pigs. / Kim, Harry K W; Aruwajoye, Olumide; Stetler, Jeffrey; Stall, Alec.

In: Journal of Bone and Joint Surgery - Series A, Vol. 94, No. 24, 19.12.2012, p. 2228-2237.

Research output: Contribution to journalArticle

@article{345f1c97777d4d3cb42fe6a890886fd7,
title = "Effects of non-weight-bearing on the immature femoral head following ischemic osteonecrosis: An experimental investigation in immature pigs",
abstract = "Background: Local non-weight-bearing as a treatment for Legg-Calv{\'e}-Perthes disease remains controversial since a clear scientific basis for this treatment is lacking. The purpose of this study was to determine the effects of non-weight-bearing on decreasing the femoral head deformity following ischemic osteonecrosis and to investigate its biological effects. Methods: Unilateral femoral head ischemia was induced in sixteen piglets by placing a ligature around the femoral neck and transecting the ligamentum teres. Eight animals received a hind-limb amputation to prevent weight-bearing on the ischemic side (NWB group). The remaining eight piglets were allowed to bear weight as tolerated (WB group). The contralateral femoral heads of the WB group were used as normal controls. All animals were killed at eight weeks after induction of ischemia, when a deformity is expected in this model. Radiographic, microcomputed tomographic (micro-CT), and histomorphometric assessments were performed. Results: Radiographic and micro-CT assessments showed significantly greater flattening of the infarcted epiphysis in the WB group compared with the NWB group. Themean epiphyseal quotient (ratio of femoral head height to diameter) was significantly lower in the WB group (0.29 ± 0.06) compared with the NWB group (0.41 ± 0.06, p < 0.001). Histomorphometric analyses showed that themean percentage revascularization of the infarcted epiphysis was significantly greater in the NWB group (95{\%} ± 14{\%}) compared with the WB group (34{\%} ± 33{\%}, p < 0.0004), suggesting that revascularization was more rapid in the NWB group. Both histomorphometric and micro-CT analyses of trabecular bone parameters showed significantly decreased bone volume and decreased trabecular number in the infarcted epiphysis of the NWB group compared with theWB group (p < 0.05). Conclusions: Local non-weight-bearing decreased the deformity following ischemic femoral head osteonecrosis and increased the rates of revascularization and resorption of the infarcted epiphysis. Clinical Relevance: Local non-weight-bearing was mechanically protective but biologically suboptimal following ischemic osteonecrosis since it increased the imbalance of bone resorption and formation.",
author = "Kim, {Harry K W} and Olumide Aruwajoye and Jeffrey Stetler and Alec Stall",
year = "2012",
month = "12",
day = "19",
doi = "10.2106/JBJS.L.00300",
language = "English (US)",
volume = "94",
pages = "2228--2237",
journal = "Journal of Bone and Joint Surgery - American Volume",
issn = "0021-9355",
publisher = "Journal of Bone and Joint Surgery Inc.",
number = "24",

}

TY - JOUR

T1 - Effects of non-weight-bearing on the immature femoral head following ischemic osteonecrosis

T2 - An experimental investigation in immature pigs

AU - Kim, Harry K W

AU - Aruwajoye, Olumide

AU - Stetler, Jeffrey

AU - Stall, Alec

PY - 2012/12/19

Y1 - 2012/12/19

N2 - Background: Local non-weight-bearing as a treatment for Legg-Calvé-Perthes disease remains controversial since a clear scientific basis for this treatment is lacking. The purpose of this study was to determine the effects of non-weight-bearing on decreasing the femoral head deformity following ischemic osteonecrosis and to investigate its biological effects. Methods: Unilateral femoral head ischemia was induced in sixteen piglets by placing a ligature around the femoral neck and transecting the ligamentum teres. Eight animals received a hind-limb amputation to prevent weight-bearing on the ischemic side (NWB group). The remaining eight piglets were allowed to bear weight as tolerated (WB group). The contralateral femoral heads of the WB group were used as normal controls. All animals were killed at eight weeks after induction of ischemia, when a deformity is expected in this model. Radiographic, microcomputed tomographic (micro-CT), and histomorphometric assessments were performed. Results: Radiographic and micro-CT assessments showed significantly greater flattening of the infarcted epiphysis in the WB group compared with the NWB group. Themean epiphyseal quotient (ratio of femoral head height to diameter) was significantly lower in the WB group (0.29 ± 0.06) compared with the NWB group (0.41 ± 0.06, p < 0.001). Histomorphometric analyses showed that themean percentage revascularization of the infarcted epiphysis was significantly greater in the NWB group (95% ± 14%) compared with the WB group (34% ± 33%, p < 0.0004), suggesting that revascularization was more rapid in the NWB group. Both histomorphometric and micro-CT analyses of trabecular bone parameters showed significantly decreased bone volume and decreased trabecular number in the infarcted epiphysis of the NWB group compared with theWB group (p < 0.05). Conclusions: Local non-weight-bearing decreased the deformity following ischemic femoral head osteonecrosis and increased the rates of revascularization and resorption of the infarcted epiphysis. Clinical Relevance: Local non-weight-bearing was mechanically protective but biologically suboptimal following ischemic osteonecrosis since it increased the imbalance of bone resorption and formation.

AB - Background: Local non-weight-bearing as a treatment for Legg-Calvé-Perthes disease remains controversial since a clear scientific basis for this treatment is lacking. The purpose of this study was to determine the effects of non-weight-bearing on decreasing the femoral head deformity following ischemic osteonecrosis and to investigate its biological effects. Methods: Unilateral femoral head ischemia was induced in sixteen piglets by placing a ligature around the femoral neck and transecting the ligamentum teres. Eight animals received a hind-limb amputation to prevent weight-bearing on the ischemic side (NWB group). The remaining eight piglets were allowed to bear weight as tolerated (WB group). The contralateral femoral heads of the WB group were used as normal controls. All animals were killed at eight weeks after induction of ischemia, when a deformity is expected in this model. Radiographic, microcomputed tomographic (micro-CT), and histomorphometric assessments were performed. Results: Radiographic and micro-CT assessments showed significantly greater flattening of the infarcted epiphysis in the WB group compared with the NWB group. Themean epiphyseal quotient (ratio of femoral head height to diameter) was significantly lower in the WB group (0.29 ± 0.06) compared with the NWB group (0.41 ± 0.06, p < 0.001). Histomorphometric analyses showed that themean percentage revascularization of the infarcted epiphysis was significantly greater in the NWB group (95% ± 14%) compared with the WB group (34% ± 33%, p < 0.0004), suggesting that revascularization was more rapid in the NWB group. Both histomorphometric and micro-CT analyses of trabecular bone parameters showed significantly decreased bone volume and decreased trabecular number in the infarcted epiphysis of the NWB group compared with theWB group (p < 0.05). Conclusions: Local non-weight-bearing decreased the deformity following ischemic femoral head osteonecrosis and increased the rates of revascularization and resorption of the infarcted epiphysis. Clinical Relevance: Local non-weight-bearing was mechanically protective but biologically suboptimal following ischemic osteonecrosis since it increased the imbalance of bone resorption and formation.

UR - http://www.scopus.com/inward/record.url?scp=84871486530&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84871486530&partnerID=8YFLogxK

U2 - 10.2106/JBJS.L.00300

DO - 10.2106/JBJS.L.00300

M3 - Article

C2 - 23318613

AN - SCOPUS:84871486530

VL - 94

SP - 2228

EP - 2237

JO - Journal of Bone and Joint Surgery - American Volume

JF - Journal of Bone and Joint Surgery - American Volume

SN - 0021-9355

IS - 24

ER -