The Journal of Bone & Joint Surgery

The Journal of Bone & Joint Surgery, Volume 91, Issue 12

Scientific Articles | December 01, 2009

Treatment of Adolescent Tibia Vara with Hemiepiphysiodesis: Risk Factors for Failure

Amy L. McIntosh, MD¹; Chad M. Hanson, MD²; Karl E. Rathjen, MD³

¹ Department of Orthopedic Surgery, Mayo Clinic, 200 First Street S.W., Rochester, MN 55905
² Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390
³ Department of Orthopedic Surgery, Texas Scottish Rite Hospital for Children, 2222 Welborn Street, Dallas, TX 75219. E-mail address: Karl.Rathjen@tsrh.org

View Disclosures and Other Information

Disclosure: The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the authors, or a member of their immediate families, are affiliated or associated.

Investigation performed at Texas Scottish Rite Hospital for Children, Dallas, Texas

The Journal of Bone and Joint Surgery, Inc.

J Bone Joint Surg Am, 2009 Dec 01;91(12):2873-2879. doi: 10.2106/JBJS.H.01245

5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case

Article

Comments (0)

text A A A

Abstract

Background: Lateral tibial hemiepiphysiodesis is an accepted surgical treatment for skeletally immature patients with adolescent tibia vara. However, the results of this procedure are unpredictable. This study was conducted to identify the risk factors associated with failure of hemiepiphysiodesis.

Methods: We studied patients with adolescent tibia vara who were at least ten years of age, had open physes, had been treated with a lateral hemiepiphysiodesis, and had been followed for at least two years. The mechanical axis deviation, medial proximal tibial angle, and lateral distal femoral angle were measured on radiographs preoperatively, at six months postoperatively, and at the time of final follow-up. Failure was defined as a residual varus deformity requiring osteotomy or a mechanical axis deviation exceeding 40 mm (moderate or severe varus) at the time of final follow-up.

Results: Forty-nine patients (forty-six male) with a total of sixty-four involved extremities met the inclusion criteria. The average age was 13.4 years, the average body mass index was 40.7 kg/m², and the average duration of follow-up was 3.3 years. The lateral hemiepiphysiodesis was unsuccessful in 66% of the patients. In a multivariate Cox proportional hazards regression analysis, the variables associated with a higher risk of failure included an age of fourteen years or more (hazard ratio = 3.9, p = 0.0009) and a body mass index of =45 kg/m² (hazard ratio = 2.8, p = 0.01). Greater deformity at baseline as indicated by a smaller medial proximal tibial angle was also found to be a significant factor in the multivariate analysis (p = 0.03).

Conclusions: Lateral hemiepiphysiodesis may be a valuable treatment option for non-morbidly obese patients with less severe adolescent tibia vara, but it is likely to fail in older adolescents with a high body mass index and greater deformity.

Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

Figures in this Article

Introduction

Idiopathic tibia vara, or "bowlegs," is thought to result from growth retardation of the medial aspect of the proximal tibial physis. Two forms of the deformity are commonly recognized: (1) infantile tibia vara, the onset of which is before the age of three years, and (2) adolescent tibia vara, with an age of onset of ten years or older¹. The typical patient with adolescent tibia vara is a male teenager, often black, with a body weight exceeding two standard deviations above the mean value for the age category (Fig. 1-A). The condition is most frequently unilateral, but bilateral involvement is seen. Widening of the medial aspect of the proximal physis is commonly observed on radiographs. This widening is greater than the dimension of the lateral side and than the physeal width in the normal, contralateral knee² (Fig. 1-B).

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-A: Clinical photograph of a typical patient with adolescent tibia vara.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-B: Standing anteroposterior radiograph of the patient shown in Fig. 1-A. Note the widened appearance of the medial aspect of the proximal tibial physis.

Because there are no effective nonoperative treatments for adolescent tibia vara, patients with substantial deformity are usually managed surgically with a proximal tibial osteotomy or so-called growth manipulation. Proximal tibial osteotomy is the most direct treatment method for the correction of this deformity. Ideally, in patients who have not reached skeletal maturity, correction to a neutral mechanical axis will restore normal biomechanical forces across the medial aspect of the physis and prevent progression or recurrence of the deformity¹. Complications following proximal tibial osteotomy include nerve palsy, compartment syndrome, infection, delayed union, and malunion^3-6. Because of the morbidity associated with proximal tibial osteotomy, lateral proximal tibial hemiepiphysiodesis (with or without distal femoral hemiepiphysiodesis) is an attractive alternative. Although hemiepiphysiodesis is associated with less morbidity, the results are somewhat unpredictable, with success rates ranging between 50% and 88% in most reports^7-10. The purpose of the present study was to identify the risk factors associated with failure of lateral hemiepiphysiodesis for the treatment of adolescent tibia vara.

Materials and Methods

Following institutional review board approval, we performed a retrospective chart and radiographic review of all patients treated for adolescent tibia vara at our institution between 1988 and 2004. We included in the study all patients who were at least ten years of age at the time of the initial diagnosis and were deemed sufficiently skeletally immature to be treated with hemiepiphysiodesis or hemiepiphyseal stapling of the lateral aspect of the proximal part of the tibia (i.e., had open physes), and had been followed for at least two years. Patients with residual infantile tibia vara, metabolic bone disease, achondroplasia, skeletal dysplasia, or previous surgical treatment of adolescent tibia vara were excluded from the study. Collected data included demographics, surgical parameters, and complications.

Of the 142 patients treated during the study period, forty-nine (sixty-four involved extremities) met the inclusion criteria. Forty-six (94%) of the patients were male, and three were female. Thirty-seven patients (76%) were black. The average age was 13.4 years (range, 10.1 to 16.4 years), and the average bone age was 13.9 years (range, 13.0 to 15.5 years). The average body mass index (calculated by dividing the patient's weight in kilograms by the square of the patient's height in meters) was 40.7 kg/m² (range, 21.3 to 58.8 kg/m²). The American Obesity Association defines childhood and adolescent obesity as a body mass index exceeding the 95th percentile. Ninety-four percent of the patients in this study had a body mass index that exceeded the 95th percentile.

Forty-two limbs (66%) underwent lateral tibial hemiepiphysiodesis, twenty limbs (31%) underwent lateral pan genu (proximal tibial and distal femoral) hemiepiphysiodesis, and two limbs (3%) underwent pan genu lateral hemiepiphyseal stapling. The hemiepiphysiodeses were done with an open technique similar to that described by Phemister¹¹. After removal of a 1-cm cube of bone with an osteotome, the physis was removed with a curet under direct visualization assisted with fiberoptic suction. The extent of the hemiepiphysiodesis was confirmed with use of fluoroscopy. The two patients treated with hemiepiphyseal stapling had three staples placed across the lateral aspect of each physis under fluoroscopic guidance.

The mechanical axis deviation, mechanical medial proximal tibial angle, and mechanical lateral distal femoral angle were measured, with use of the method of Paley and Tetsworth (Fig. 2)¹², on standardized standing long-cassette anteroposterior radiographs of the lower extremity before the surgery, at six months postoperatively, and at the time of final follow-up. All radiographic measurements were performed by the same investigator, who was not involved with the surgical procedures. Mechanical axis deviation was defined as the distance of the mechanical axis from the center of the knee. To measure this distance, the knee joint was divided into eight zones (Fig. 3) on the basis of a modification of the method originally described by Muller and popularized by Mielke and Stevens¹³. The zone through which the mechanical axis passed was recorded at all follow-up intervals. Normal alignment was defined as a mechanical axis passing through zone 1 or -1. Mild varus was defined as a mechanical axis passing through zone -2, with a mechanical axis deviation ranging from 20 to 40 mm medial to the knee joint center. Moderate varus was defined as a mechanical axis passing through zone -3, with a mechanical axis deviation ranging from 41 to 80 mm medial to the knee joint center. Severe varus was defined as a mechanical axis passing through zone -4, with a mechanical axis deviation of >80 mm medial to the knee joint center.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 2: Schematic diagram showing the techniques for determining the mechanical lateral distal femoral angle (LDFA), mechanical medial proximal tibial angle (MPTA), and mechanical axis deviation (MAD).

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 3: Schematic diagram showing the zones of the mechanical axis. L = lateral, and M = medial.

Failure of treatment was defined as a residual varus deformity requiring osteotomy or moderate or severe varus alignment (a mechanical axis passing through zone -3 or -4, with a mechanical axis deviation of >40 mm medial to the knee joint center) at the time of final follow-up.

Statistical Analysis

The associations of patient characteristics and preoperative deformity measures with failure were assessed with use of univariate Cox proportional hazards regression. Age, body mass index, weight, medial proximal tibial angle, and mechanical axis deviation were each assessed as continuous variables and as binary variables based on the optimal cutpoint to aid in clinical interpretation. Variables showing significance or a trend toward significance (p < 0.20) in the univariate analysis were then assessed in multivariate Cox proportional hazards models; stepwise model-selection procedures were also used to assist in choosing the final model. Since several patients had a bilateral procedure and thus had two limbs included in the analysis, the robust sandwich estimator of variance (COVSANDWICH option [SAS Institute, Cary, North Carolina]) was used to account for this correlation within subject for all Cox models. Results are reported as hazard ratios with 95% confidence intervals and p values. Significance was set at the 0.05 level.

Source of Funding

This study had no external source of funding.

Results

The average duration of radiographic and clinical follow-up was 3.3 years (range, 2.1 to 5.0 years). All patients were skeletally mature at the time of final follow-up. The average mechanical medial proximal tibial angle was 76° (range, 61° to 87°) preoperatively and 78° (range, 53° to 94°) at final measurement. The average mechanical lateral distal femoral angle was 94° (range, 87° to 103°) preoperatively and 92° (range, 80° to 105°) at the time of final follow-up. The average varus preoperative mechanical axis deviation was 97 mm (range, 22 to 150 mm). At the time of final follow-up, the average mechanical axis deviation measured 73 mm (range, 34 mm of valgus to 154 mm of varus) medial to the knee joint center (Table I).

View Larger

TABLE I Radiographic Measurements

	Preoperative*	Postoperative*	P Value
Mechanical axis deviation (mm)	97 (22-150) varus	73 varus (34 valgus-154 varus)	0.0001
Mechanical medial proximal tibial angle (deg)	76 (61-87)	78 (53-94)	0.01
Mechanical lateral distal femoral angle (deg)	94 (87-103)	92 (80-105)	0.001

The values are given as the average with the range in parentheses.

Add to My JBJS

TABLE I Radiographic Measurements

	Preoperative*	Postoperative*	P Value
Mechanical axis deviation (mm)	97 (22-150) varus	73 varus (34 valgus-154 varus)	0.0001
Mechanical medial proximal tibial angle (deg)	76 (61-87)	78 (53-94)	0.01
Mechanical lateral distal femoral angle (deg)	94 (87-103)	92 (80-105)	0.001

The values are given as the average with the range in parentheses.

Preoperatively, the mechanical axis passed through zone -2 (mild varus deformity) in eight knees, zone -3 (moderate varus deformity) in thirty knees, and zone -4 (severe varus deformity) in twenty-six knees. At the time of final follow-up, the mechanical axis was in neutral alignment (zone -1 or 1) in fourteen extremities, in mild varus (zone -2) in seven extremities, and in mild valgus (zone 2) in one extremity. Hemiepiphysiodesis was considered to have been successful in these twenty-two limbs (34%). Nine of these limbs underwent medial completion epiphysiodesis once satisfactory correction had been achieved. The remaining forty-two limbs (66%) in the series were classified as failures of treatment. Twenty-one extremities required a proximal tibial osteotomy to correct the residual deformity. In addition, thirteen extremities had moderate varus (zone -3) and eight had severe varus (zone -4) at the time of final follow-up but did not undergo additional operative treatment.

The degree of preoperative deformity appeared to influence the outcome of the hemiepiphysiodesis. Of the eight extremities with mild varus deformity (zone -2) preoperatively, five had a neutral mechanical axis (zone -1 or 1) at the time of final follow-up, one remained unchanged at the time of final follow-up, and two had worsening of the deformity to moderate varus (zone -3) at the time of final follow-up (Table II). The two extremities with moderate deformity (zone -3) at the time of final follow-up underwent a proximal tibial osteotomy.

View Larger

TABLE II Alignment After Hemiepiphysiodesis According to Preoperative Varus Deformity

	Postoperative Deformity (no. of extremities)
	Mild Valgus Overcorrection	Normal	Mild Varus	Moderate Varus	Severe Varus
Preoperative deformity
Mild varus (n = 8)		5	1	2	0
Moderate varus (n = 30)		8	5	13	4
Severe varus (n = 26)	1	1	1	7	16

Add to My JBJS

TABLE II Alignment After Hemiepiphysiodesis According to Preoperative Varus Deformity

	Postoperative Deformity (no. of extremities)
	Mild Valgus Overcorrection	Normal	Mild Varus	Moderate Varus	Severe Varus
Preoperative deformity
Mild varus (n = 8)		5	1	2	0
Moderate varus (n = 30)		8	5	13	4
Severe varus (n = 26)	1	1	1	7	16

Thirteen (43%) of the thirty extremities with a preoperative moderate varus deformity (zone -3) had a successful result, with eight of the thirteen having a neutral mechanical axis (zone -1 or 1) and five having a mild varus deformity (zone -2) at the time of final follow-up. An additional thirteen extremities (43%) remained unchanged, with a moderate varus deformity (zone -3) at the time of final follow-up, and four (13%) extremities had worsening to a severe varus deformity (zone -4) at the time of final follow-up (Table II). Thus, seventeen (57%) of the extremities that had had a preoperative moderate varus deformity were considered failures of treatment, and five underwent a proximal tibial osteotomy.

Only three (12%) of the twenty-six extremities with a severe varus deformity (zone -4) preoperatively had a successful result. Of these three, one had valgus overcorrection (zone 2), one had a neutral mechanical axis (zone -1), and one had a mild varus deformity (zone -2). Seven extremities (27%) had improvement to a moderate varus deformity (zone -3) and sixteen (62%) still had a severe varus deformity (zone -4) at the time of final follow-up (Table II). Thus twenty-three (88%) of the extremities with a severe varus deformity preoperatively had a failure of the hemiepiphysiodesis, and fourteen (54%) subsequently underwent a proximal tibial osteotomy. These results are summarized in Figure 4.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 4: Failure of hemiepiphysiodesis as related to the magnitude of the preoperative varus deformity.

Univariate Cox proportional hazards regression analysis identified four significant risk factors for failure of hemiepiphysiodesis (Table III): older age, a smaller medial proximal tibial angle, a body mass index of =45 kg/m², and the zone of preoperative deformity. Multivariate modeling and stepwise model selection suggested a final model that included age, body mass index, and the medial proximal tibial angle as significant risk factors. Girls were also found to have a significantly higher risk of failure despite the fact that only three girls were included in this analysis. We could not identify any effect of the type of surgical procedure on the failure rate.

View Larger

TABLE III Results of Univariate Cox Proportional Hazards Analysis for the Failure Outcome

Variable	Hazard Ratio	95% Confidence Limits	P Value
Age, per 1-yr increase	1.4	1.1-1.7	0.01
Age =14 vs. <14 yr	4.2	1.9-9.4	0.0004
Male vs. female	0.6	0.3-1.2	0.17
Medial proximal tibial angle, per 1° decrease	0.92	0.85-0.99	0.03
Medial proximal tibial angle <76° vs. =76°	1.7	1.0-3.0	0.06
Lateral distal femoral angle, per 1° increase	1.0	0.9-1.1	0.89
Body mass index, per 1-kg/m² increase	1.03	0.99-1.07	0.20
Body mass index =45 vs. <45 kg/m²	2.9	1.3-6.8	0.01
Weight, per 1-kg increase	1.01	1.00-1.02	0.06
Weight =108 vs. <108 kg	1.7	0.9-3.5	0.11
Mechanical axis deviation, per 1-mm increase	0.99	0.98-1.00	0.14
Mechanical axis deviation =80 vs. <80 mm	2.0	1.0-3.9	0.06
Zone*, per 1-zone decrease	0.6	0.3-1.0	0.04
Bilateral vs. unilateral	1.5	0.7-2.9	0.29
Race			0.85 (overall)
Black	1.1	0.6-1.9	0.79
Hispanic	0.7	0.2-3.3	0.66
White	Reference

Zone through which the mechanical axis passes, as defined by Mielke and Stevens¹³.

Add to My JBJS

TABLE III Results of Univariate Cox Proportional Hazards Analysis for the Failure Outcome

Variable	Hazard Ratio	95% Confidence Limits	P Value
Age, per 1-yr increase	1.4	1.1-1.7	0.01
Age =14 vs. <14 yr	4.2	1.9-9.4	0.0004
Male vs. female	0.6	0.3-1.2	0.17
Medial proximal tibial angle, per 1° decrease	0.92	0.85-0.99	0.03
Medial proximal tibial angle <76° vs. =76°	1.7	1.0-3.0	0.06
Lateral distal femoral angle, per 1° increase	1.0	0.9-1.1	0.89
Body mass index, per 1-kg/m² increase	1.03	0.99-1.07	0.20
Body mass index =45 vs. <45 kg/m²	2.9	1.3-6.8	0.01
Weight, per 1-kg increase	1.01	1.00-1.02	0.06
Weight =108 vs. <108 kg	1.7	0.9-3.5	0.11
Mechanical axis deviation, per 1-mm increase	0.99	0.98-1.00	0.14
Mechanical axis deviation =80 vs. <80 mm	2.0	1.0-3.9	0.06
Zone*, per 1-zone decrease	0.6	0.3-1.0	0.04
Bilateral vs. unilateral	1.5	0.7-2.9	0.29
Race			0.85 (overall)
Black	1.1	0.6-1.9	0.79
Hispanic	0.7	0.2-3.3	0.66
White	Reference

Zone through which the mechanical axis passes, as defined by Mielke and Stevens¹³.

Multivariate models with age, body mass index, and the medial proximal tibial angle as continuous variables and as binary variables are shown in Table IV. Patients with a body mass index of =45 kg/m² had a 2.8-fold increase (95% confidence interval = 1.3 to 6.0, p = 0.01) in the risk of failure compared with those with a body mass index of <45 kg/m². Patients who were fourteen years of age or more had a 3.9-fold increase (95% confidence interval = 1.8 to 8.8, p = 0.0009) in the risk of failure compared with those who were younger than fourteen. The average age of the patients with a body mass index of =45 kg/m² was 13.3 years (range, 11.4 to 16.4 years), and the average age of the patients with a body mass index of <45 kg/m² was 13.4 years (range, 10.1 to 16.4 years). The risk factors appeared to be additive: hemiepiphysiodesis failed in eleven of twelve patients with a medial proximal tibial angle of <75° and a body mass index >35 kg/m² and in all eleven patients with a medial proximal tibial angle <84°, a body mass index of >35 kg/m², and a chronological age of more than fourteen years.

View Larger

TABLE IV Results of Multivariate Cox Proportional Hazards Analysis for the Failure Outcome*

Variable	Hazard Ratio	95% Confidence Limits	P Value
Model 1
Age, per 1-yr increase	1.6	1.3-2.0	<0.0001
Male vs. female	0.4	0.2-0.9	0.03
Medial proximal tibial angle, per 1° increase	0.9	0.8-1.0	0.03
Body mass index, per 1-kg/m² increase	1.05	1.03-1.08	<0.0001
Model 2
Age =14 vs. <14 yr	3.9	1.8-8.8	0.0009
Male vs. female	0.3	0.1-0.7	0.007
Medial proximal tibial angle <76° vs. =76°	1.7	0.9-3.1	0.12
Body mass index =45 vs. <45 kg/m²	2.8	1.3-6.0	0.01

In Model 1, age, medial proximal tibial angle, and body mass index are continuous variables. In Model 2, these variables are binary on the basis of the optimal cutpoint.

Add to My JBJS

TABLE IV Results of Multivariate Cox Proportional Hazards Analysis for the Failure Outcome*

Variable	Hazard Ratio	95% Confidence Limits	P Value
Model 1
Age, per 1-yr increase	1.6	1.3-2.0	<0.0001
Male vs. female	0.4	0.2-0.9	0.03
Medial proximal tibial angle, per 1° increase	0.9	0.8-1.0	0.03
Body mass index, per 1-kg/m² increase	1.05	1.03-1.08	<0.0001
Model 2
Age =14 vs. <14 yr	3.9	1.8-8.8	0.0009
Male vs. female	0.3	0.1-0.7	0.007
Medial proximal tibial angle <76° vs. =76°	1.7	0.9-3.1	0.12
Body mass index =45 vs. <45 kg/m²	2.8	1.3-6.0	0.01

In Model 1, age, medial proximal tibial angle, and body mass index are continuous variables. In Model 2, these variables are binary on the basis of the optimal cutpoint.

Discussion

Since there is no known effective nonoperative treatment for substantial degrees of adolescent tibia vara, patients usually undergo surgical treatment. Surgical treatment options for adolescent tibia vara include corrective valgus osteotomy of the proximal part of the tibia^7,14 and lateral hemiepiphysiodesis of the proximal part of the tibia and/or distal part of the femur. Valgus osteotomy of the proximal part of the tibia is a considerable undertaking in any patient and is made even more challenging by the obesity of most patients with adolescent tibia vara. Problems associated with a valgus tibial osteotomy include delayed wound-healing, nonunion, compartment syndrome, nerve palsy, and infection^3,5,6,14,15. Hemiepiphysiodesis is attractive as a surgical option because it is a less invasive procedure that does not require immobilization or non-weight-bearing in the postoperative period. Reported rates of success of hemiepiphysiodesis for the treatment of adolescent tibia vara have ranged from 50% to 88%^7-10.

There are a few notable differences between our study and those in the literature. Park et al.⁹ reported "success" in twenty-six (79%) of thirty-three extremities treated with hemiepiphyseal stapling, although only one of four patients with a severe preoperative varus deformity (zone -4) had success. Also Park et al. did not address body mass index. The mean age of their patients was 11.8 years compared with 13.4 years in our study. Westberry et al.¹⁰ also reported on hemiepiphysiodesis for genu varum deformity in children. Their cohort of thirty-three extremities included both those with adolescent tibia vara and those with infantile tibia vara. Twenty-four of the thirty-three extremities had a successful result and did not require a valgus osteotomy. Westberry et al. reported decreasing success with increasing deformity, although they could not establish the upper limit of the tibia vara beyond which hemiepiphysiodesis was not effective.

The limitations of our study include its retrospective design, a small sample size, and the fact that multiple surgeons performed several different procedures. Gordon et al.¹⁶ emphasized the importance of evaluating femoral varus deformity in the treatment of adolescent tibia vara. While many (twenty-two) of our patients underwent pan genu hemiepiphysiodesis, it was performed at the surgeons' discretion, on a case-by-case basis, when distal femoral varus was thought to be a major contributor to the overall varus alignment of the limb.

Another confounding factor in our study is the older age of a number of our patients. Although Inan et al.¹⁷ suggested that residual growth can be most accurately predicted with use of the Angular Deformity Versus Growth Remaining Chart¹⁸, this chart was not utilized in our study. It is possible that not all of our patients had enough remaining growth for satisfactory correction with hemiepiphysiodesis to be achieved. Although statistical analysis identified an age of fourteen years or greater as being associated with an increased risk of failure, it is important to note that failure occurred in the limbs of patients of all ages: one of the two in the ten-year-old group, three of the five in the eleven-year-old group, ten of the sixteen in the twelve-year-old group, seventeen of the twenty-seven in the thirteen-year-old group, and eleven of the fourteen in the group fourteen years or older. Thus, age does not appear to be as strong a predictive factor as the severity of the initial deformity.

It could be argued that our definition of "success" is too inclusive and that patients with even mild residual deformity are at risk for accelerated degenerative changes and should be considered to have a failure of treatment. If the eight patients with mild residual deformity were considered to have had a treatment failure, the operation would have been successful in only fourteen of the sixty-four limbs and the failure rate would increase to 77% (forty-nine of sixty-four). However, our experience has been that "normal" alignment is often poorly tolerated in this population of obese patients with massive thighs¹⁹. Subsequently, we believe that slight undercorrection is often an acceptable, if not desired, clinical result.

It should also be recognized that, although obesity was identified as a risk factor for failure of hemiepiphysiodesis, the study group was not large enough to provide sufficient strength to establish causality or identify a threshold for obesity.

In conclusion, lateral hemiepiphysiodesis for the treatment of adolescent tibia vara should be reserved for younger patients (less than fourteen years old) with mild preoperative varus deformity and less morbid obesity (a body mass index of <45 kg/m²). Prospective studies are needed to better understand the role of hemiepiphysiodesis in the treatment of varus deformity about the knee in patients with adolescent tibia vara, and longer-term studies with clinical follow-up are needed to document the late effects of this disease process into adulthood. Image Not Available

Acknowledgements

Note: The authors thank Tanya L. Hoskin, MS, statistician of the Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.

References

Thompson GH, Carter JR. Late-onset tibia vara (Blount's disease). Current concepts. Clin Orthop Relat Res.1990;255:24-35.25524 1990 [PubMed]

Beskin JL, Burke SW, Johnston CE 2nd, Roberts JM. Clinical basis for a mechanical etiology in adolescent Blount's disease. Orthopedics.1986;9:365-70.9365 1986

Slawski DP, Schoenecker PL, Rich MM. Peroneal nerve injury as a complication of pediatric tibial osteotomies: a review of 255 osteotomies. J Pediatr Orthop.1994;14:166-72.14166 1994 [CrossRef]

Loder RT, Schaffer JJ, Bardenstein MB. Late-onset tibia vara. J Pediatr Orthop.1991;11:162-7.11162 1991 [CrossRef]

Steel HH, Sandrow RE, Sullivan PD. Complications of tibial osteotomy in children for genu varum or valgum. Evidence that neurological changes are due to ischemia. J Bone Joint Surg Am.1971;53:1629-35.531629 1971

Mycoskie PJ. Complications of osteotomies about the knee in children. Orthopedics.1981;4:1005-15.41005 1981

Henderson RC, Kemp GJ Jr, Greene WB. Adolescent tibia vara: alternatives for operative treatment. J Bone Joint Surg Am.1992;74:342-50.74342 1992

Johnston CE 2nd, Bueche MJ, Williamson B, Birch JG. Epiphysiodesis for management of lower limb deformities. Instr Course Lect.1992;41:437-44.41437 1992

Park SS, Gordon JE, Luhmann SJ, Dobbs MB, Schoenecker PL. Outcome of hemiepiphyseal stapling for late-onset tibia vara. J Bone Joint Surg Am.2005;87:2259-66.872259 2005 [CrossRef]

Westberry DE, Davids JR, Pugh LI, Blackhurst D. Tibia vara: results of hemiepiphyseodesis. J Pediatr Orthop B.2004;13:374-8.13374 2004 [CrossRef]

Phemister DB. Operative arrestment of longitudinal growth of bones in the treatment of deformities. J Bone Joint Surg Am.1933;15:1-15.151 1933

Paley D, Tetsworth K. Mechanical axis deviation of the lower limbs. Preoperative planning of multiapical frontal plane angular and bowing deformities of the femur and tibia. Clin Orthop Relat Res.1992;280:65-71.28065 1992

Mielke CH, Stevens PM. Hemiepiphyseal stapling for knee deformities in children younger than 10 years: a preliminary report. J Pediatr Orthop.1996;16:423-9.16423 1996 [CrossRef]

Schoenecker PL, Meade WC, Pierron RL, Sheridan JJ, Capelli AM. Blount's disease: a retrospective review and recommendations for treatment. J Pediatr Orthop.1985;5:181-6.5181 1985

Stanitski DF, Dahl M, Louie K, Grayhack J. Management of late-onset tibia vara in the obese patient by using circular external fixation. J Pediatr Orthop.1997;17:691-4.17691 1997

Gordon JE, Heidenreich FP, Carpenter CJ, Kelly-Hahn J, Schoenecker PL. Comprehensive treatment of late-onset tibia vara. J Bone Joint Surg Am.2005;87:1561-70.871561 2005 [CrossRef]

Inan M, Chan G, Bowen JR. Correction of angular deformities of the knee by percutaneous hemiepiphysiodesis. Clin Orthop Relat Res.2007;456:164-9.456164 2007

Bowen JR, Johnson WJ. Percutaneous epiphysiodesis. Clin Orthop Relat Res.1984;190:170-3.190170 1984

Davids JR, Huskamp M, Bagley AM. A dynamic biomechanical analysis of the etiology of adolescent tibia vara. J Pediatr Orthop.1996;16:461-8.16461 1996 [CrossRef]

Topics

obesity ; body mass index procedure ; limb ; femur ; tibia ; blount's disease ; varus deformity

Username

Password

Access for Patients

Forgot Password?

Have a subscription to the print edition?

Not a Subscriber?

Buy this Article

Get online access for 30 days for $35

New to JBJS?

Subscribe to the online edition for 30 days for $75

Register for a FREE limited account to get full access to all CME activities, to comment on public articles, or to sign up for alerts.

Have a subscription to the print edition?

Current subscribers to The Journal of Bone & Joint Surgery in either the print or quarterly DVD formats receive free online access to JBJS.org.

Activate your online account now

Forgot your password?

Enter your username and email address. We'll send you a reminder to the email address on record.

Username:*

Email Address:*

Forgot your username or need assistance? Please contact customer service at subs@jbjs.org. If your access is provided
by your institution, please contact you librarian or administrator for username and password information. Institutional
administrators, to reset your institution's master username or password, please contact subs@jbjs.org

References

Accreditation Statement

These activities have been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint sponsorship of the American Academy of Orthopaedic Surgeons and The Journal of Bone and Joint Surgery, Inc. The American Academy of Orthopaedic Surgeons is accredited by the ACCME to provide continuing medical education for physicians.

CME Activities Associated with This Article

Submit a Comment

Please read the other comments before you post yours. Contributors must reveal any conflict of interest.
Comments are moderated and will appear on the site at the discretion of JBJS editorial staff.

* = Required Field

Comment Author(s) * (if multiple authors, separate names by comma)

Example: John Doe

Affiliation & Institution*

Comment Title*

Comment*

Cancel

Print
PDF
Email

Recipient(s) will receive an email with a link (good for 5 days) to 'Treatment of Adolescent Tibia Vara with Hemiepiphysiodesis: Risk Factors for Failure'.
Your Name:*
Example: John Doe

Email Address:* CC Me:
Enter your valid email address. Example: jdoe@example.com

Recipient's Email Address:*

Separate multiple email address with semi-colons (up to 5).

Subject:* 's The Journal of Bone & Joint Surgery: 'Treatment of Adolescent Tibia Vara with Hemiepiphysiodesis: Risk Factors for Failure'
Subject for your email.

Message:

(Optional, message will truncate at 1000 characters)

Processing your request... Please Wait...

Copyright © in the material you requested is held by The Journal of Bone & Joint Surgery, Inc. (unless otherwise noted). This email ability is provided as a courtesy, and by using it you agree that that you are requesting the material solely for personal, non-commercial use, and that it is subject to Journal of Bone & Joint Surgery, Inc.'s Terms of Use. The information provided in order to email this topic will not be used to send unsolicited email, nor will it be furnished to third parties. Please refer to The Journal of Bone & Joint Surgery Inc.'s Privacy Policy for further information.

Copyright © The Journal of Bone & Joint Surgery Inc. All rights reserved.
Share
Get Citation

Amy L. McIntosh, Chad M. Hanson, Karl E. Rathjen; Treatment of Adolescent Tibia Vara with Hemiepiphysiodesis: Risk Factors for Failure. The Journal of Bone & Joint Surgery. 2009 Dec;91(12):2873-2879.

Download citation file:

RIS (Zotero)

EndNote

BibTex

Medlars

ProCite

RefWorks

Reference Manager

Copyright © The Journal of Bone and Joint Surgery, Inc.
Rights & Permissions
Article Alerts

Processing your request... Please Wait.
Submit a Comment