Anthropometric and Skeletal Parameters Predict 2-Strand Semitendinosus Tendon Size in Double-Bundle Anterior Cruciate Ligament Reconstruction

Abstract

Background:

Few studies have examined whether skeletal parameters predict hamstring graft size during anterior cruciate ligament reconstruction (ACLR).

Purpose/Hypothesis:

The purpose of this study was to examine whether preoperative anthropometric and radiographic skeletal parameters could predict hamstring graft size during ACLR. We hypothesized that both anthropometric and skeletal parameters can be used to predict graft size in our double-bundle procedure and that the use of skeletal parameters will improve the accuracy of graft size prediction.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 200 patients were recruited and underwent double-bundle ACLR using a semitendinosus (ST) graft. The harvested tendon was measured to determine graft length (GL) and then split at its midpoint. The graft diameters of the anteromedial (GD_AM) and posterolateral bundles (GD_PL) were measured at the femoral aspect of the 2-stranded graft. The mean diameters of both bundles were included in the analysis. On the coronal radiograph, femorotibial angle (FTA), femoral interepicondylar distance (IED), and tibial plateau width (coronal tibial width [CTW]) were measured. Blumensaat line length (BLL) and the lateral tibial width (LTW) were measured on the lateral radiograph. A linear regression analysis was conducted using graft size as the dependent variable and age, sex, height, weight, Tegner activity score, and skeletal parameters as the independent variables.

Results:

Mean GL was 258.9 ± 21.9 mm, GD_AM was 5.9 ± 0.5 mm, and GD_PL was 5.7 ± 0.6 mm. Single regression analysis showed that GL was significantly predicted by sex, height, weight, Tegner activity score, IED, CTW, BLL, and LTW (R ² range, 0.033-0.342). GD was predicted by sex, height, weight, IED, CTW, BLL, and LTW (R ² range, 0.094-0.207). Stepwise multiple linear regression analysis significantly confirmed sex, height, and age as the variables to comprehensively predict GL (R ² = 0.384). With regard to GD, stepwise multiple regression confirmed height and IED as significant variables (R ² = 0.224).

Conclusion:

Both preoperative anthropometric and radiographic parameters on plain radiographs were able to predict harvested GL and 2-strand GD. Multivariate regression slightly improved the prediction of graft dimensions compared with univariate regression.

Keywords

anterior cruciate ligament reconstruction hamstring graft graft size prediction skeletal structure

There exist several choices for autografts in anterior cruciate ligament reconstruction (ACLR), such as the hamstring tendon,^7,30,51 bone–patellar tendon–bone (BTB),^33,41 and quadriceps tendon.^14,39,53 Many previous studies have reported that hamstring autografts show comparable biomechanical properties and clinical outcomes to those of central-third BTB grafts.^§ Additionally, during harvest, BTB occasionally causes anterior knee pain at the harvested site,^{2,17,18,20,48} while morbidity is considered less common after hamstring autografts.^1,4,35 Hamstring autografts are useful because surgeons can control their size by folding them.^4,6,11 Moreover, surgeons are able to choose hamstring tendons as the suitable autograft when they must reconstruct joints other than the knee, such as the elbow or ankle joint.^16,22,45 Thus, the use of hamstring autografts has become increasingly popular in ligament reconstruction surgery.

When a primary ACLR is performed at our institution, only semitendinosus (ST) grafts are harvested, halved for the double-bundle graft, and folded into 2 strands. The gracilis tendon (GT) is preserved as much as possible in preparation for future revision reconstructions^27,40 or other ligament reconstructions such as medial collateral ligament,²¹ patellofemoral ligament,^12,23,42 or multiple ligament^8,13,44 injuries. Although hamstring autografts are reportedly preferable for ACLR, harvested hamstring tendons may be of insufficient length and diameter because of the patient’s anthropometrics and the technique used by the surgeon.^∥ Inadequate harvested tendon size will make the graft diminutive. Hence, surgeons need to reconsider how to organize the diminutive graft intraoperatively by augmentation, changing of graft source, or surgical procedure (double- to single-bundle technique) since a smaller diameter is associated with lower strength transplanted grafts and reconstruction failure.^{5,11,25,26,28,32} If surgeons can predict hamstring autograft size, they will be able to conduct preoperative planning more carefully.

Most previous studies have aimed to elucidate graft size prediction in ACLR using 4-strand ST or gracilis grafts, and anthropometric parameters were available to predict hamstring autograft size.^¶ According to previous data of a single regression model using anthropometrics, the reproducibility of predicting the graft size appears not high.^4,47,52 Few studies have been designed to predict 2-strand grafts in double-bundle ACLR using the ST. The current study aimed to evaluate whether a patient’s preoperative anthropometric characteristics can be used to similarly predict 2-strand graft size in double-bundle ACLR using ST. Additionally, as a novel factor, we evaluated whether skeletal radiographic parameters predict ST graft size. Our hypothesis was that both anthropometric and radiographic parameters can be used to predict graft size in our double-bundle procedure and that radiographic parameter improves graft size prediction accuracy.

Methods

A total of 208 patients underwent primary double-bundle ACLR with an autologous hamstring tendon graft at our institution between April 2010 and April 2015. When the harvested ST was less than 230 mm or the 2-strand graft diameter was less than 5.0 mm, the GT was additionally harvested and augmented to the anteromedial bundle (AM) graft. In the current series, 6 patients were augmented by GT. Eight patients were not enrolled in the study because of insufficient data. Ultimately, 200 patients (87 men and 113 women) who underwent ACLR using the ST participated in this study. Anthropometric characteristics such as height and weight were obtained from the medical and surgical records. Tegner activity score was also obtained. Leg length and thigh circumference were not recorded since these parameters were less accurate indicators of graft dimensions, compared with height.^10,36,47 Each patient was informed of the current study’s aims and risks, and all agreed to participate. The ethical committee of our hospital approved this study.

Radiographic Measurements

Radiographs in the current study were obtained by experienced radiologic technicians with a film-focus distance of 130 cm, 60 kV, 200 mA, and 50 ms. The weightbearing anteroposterior knee radiographs were obtained with the knee fully extended and rotated, with the patella in the center of the femoral condyle. The beam was aligned relative to the joint space and positioned parallel to the floor with no angle. The distance between the medial and lateral femoral epicondyles (interepicondylar distance [IED]) was measured on the anteroposterior radiograph. The tibial plateau width (coronal tibial width [CTW]) was also measured (Figure 1). In addition, the femorotibial angle (FTA) was measured by the axis of the femoral and tibial shafts.

Figure 1.

Radiographic evaluation of the skeletal parameters. The tibial plateau size was measured at the level of the subchondral bone. The Blumensaat line was measured as the line connecting its anterior and posterior edges.

The lateral knee radiographs were obtained with the knee flexed at 55°. The beam was aligned relative to the joint space and angled 5° caudally. On the lateral radiograph, the Blumensaat line length (BLL) and tibial plateau length (lateral tibial width [LTW]) were measured (Figure 1). Tibial plateau size was measured at the level of the subchondral bone. Blinding the information of graft dimension, all the radiographic parameters were measured by a single orthopaedic surgeon (9-year career) in our hospital using a picture archiving and communication system; the intrarater reliability (intraclass correlation [1, 1]) was 0.965 for IED, 0.932 for CTW, 0.891 for BLL, and 0.924 for LTW.

Intraoperative Graft Preparation and Evaluation

The ST graft was harvested through an anteromedial incision over the attachment of the pes anserinus on the tibial side. The insertion of the ST was sharply elevated off of the tibia along with periosteum. The proximal tendon was then harvested with a closed tendon stripper. Proximal muscle fibers and adipose tissue around the harvested tendon were removed. The total graft length (GL, mm) of the removed tendon was measured from end to end in 10-mm increments using a ruler (Figure 2A).

Figure 2.

Evaluation of graft lengths and diameter. (A) Evaluation of graft length of the semitendinosus tendon. (B) Overview of the 2-strand graft. (C) Evaluation of the 2-strand graft diameter; measurements were calculated from the end of the femoral socket (2-strand graft was passed through the cylindrical device in the direction indicated by the arrow).

The harvested tendon was cut at its midpoint, stitched with a nonabsorbable suture at both ends, and folded to create the 2-strand graft (Figure 2B). The graft diameter (GD, mm) of the 2-strand graft was measured at the folded end in 0.5-mm increments using a cylinder device (Figure 2C), and the folded end was inserted into the femoral socket. The GD of the stitched end was measured in the same manner, and the stitched end was inserted into the tibial socket. In this study, the GD of the folded end was applied since the stitched end was increased in diameter because of the suture.⁵² Finally, the GD was measured as the mean value of the femoral socket AM and posterolateral (PL) grafts.

Statistical Analysis

Statistical analyses were performed using SPSS version 22.0 (SPSS Inc). An unpaired t test was used to compare mean continuous values between men and women. The relationship between the GL or GD and anthropometric and radiographic parameters was investigated using the Pearson correlation coefficient. To establish the equation for predicting the graft dimension, single and multiple regression analyses were used with the GL or GD as the dependent variable and with anthropometric and radiographic parameters as independent variables in each regression. The stepwise selection method of the multiple regression analyses was used for determining significant predictor variables. Values of P < .05 were considered statistically significant.

Results

The mean GL was 258.9 ± 21.9 mm, and the mean GD was 5.8 ± 0.5 mm. Mean age, height, weight, body mass index, IED, CTW, BLL, LTW, GL, and GD were significantly higher in males than in females (Table 1). GL was positively correlated with height, weight, Tegner activity score, IED, CTW, BLL, and LTW. Of these parameters, height had the highest coefficient (r = 0.588) and was moderately correlated with GL. GD was positively correlated with height, weight, Tegner activity score, IED, CTW, BLL, and LTW. Of these parameters, height and IED had the highest coefficients but again were only moderately correlated with GD. The correlation coefficients of weight and IED were higher in GD than in GL (Table 2).

TABLE 1

Demographic and Radiographic Data ^a

	Overall (N = 200)		Male (n = 87),	Female (n = 113),
	Mean ± SD	Range	Mean ± SD	Mean ± SD
Age, y	25.6 ± 13	11-68	28.2 ± 13.2 ^b	23.5 ± 12.6
Height, cm	165.6 ± 8	148.4-191	171.5 ± 6.6 ^b	161.1 ± 5.8
Weight, kg	63.5 ± 11.9	41.7-107	70.1 ± 11.4 ^b	58.4 ± 9.7
BMI, kg/m²	23.1 ± 3.5	16.2-43.2	23.8 ± 3.3 ^b	22.5 ± 3.6
Tegner	6.4 ± 1.9	1-10	6.7 ± 1.8	6.2 ± 2.0
FTA, deg	177.3 ± 2.4	167.1-187.5	177.4 ± 2.2	177.2 ± 2.6
IED, mm	84.5 ± 7.8	51.4-104	91.0 ± 6.4 ^b	79.4 ± 4.3
CTW, mm	76.4 ± 6.8	63.9-94.7	82.4 ± 4.3 ^b	71.8 ± 4.2
BLL, mm	28.3 ± 2.8	22.7-38.9	30.4 ± 2.2 ^b	26.6 ± 2.0
LTW, mm	51.8 ± 4.7	42.4-71.7	55.2 ± 4.0 ^b	49.2 ± 3.3
GL, mm	258.9 ± 21.9	200-350	271.1 ± 20.3 ^b	249.4 ± 18.2
GD_AM, mm	5.9 ± 0.5	5-7	6.1 ± 0.5 ^b	5.8 ± 0.4
GD_PL, mm	5.7 ± 0.6	4.5-7	6.0 ± 0.5 ^b	5.6 ± 0.5
GD, mm	5.8 ± 0.5	4.8-7	6.0 ± 0.5 ^b	5.7 ± 0.4

^a AM, anteromedial bundle; BLL, Blumensaat line length; BMI, body mass index; CTW, coronal tibial width; FTA, femorotibial angle; GD, graft diameter; GL, graft length; IED, interepicondylar distance; LTW, lateral tibial width; PL, posterolateral bundle.

^bP < .05 compared with females.

TABLE 2

Statistical Analysis: Pearson Correlation (r) Between Graft Size and Demographic and Radiographic Data ^a

	GD_AM	GD_PL	Age	Sex	Height	Weight	BMI	Tegner	FTA	IED	CTW	BLL	LTW
GL	0.155 ^b	0.286 ^c	−0.112	−0.493 ^c	0.588 ^c	0.273 ^c	−0.045	0.195 ^c	0.056	0.398 ^c	0.423 ^c	0.485 ^c	0.420 ^c
GD_AM	—	0.740 ^c	0.098	−0.316 ^c	0.415 ^c	0.258 ^c	0.034	−0.024	0.111	0.416 ^c	0.352 ^c	0.334 ^c	0.364 ^c
GD_PL		—	0.002	−0.353 ^c	0.438 ^c	0.313 ^c	0.085	0.028	0.030	0.460 ^c	0.418 ^c	0.416 ^c	0.387 ^c

^bP < .05.

^cP < .01.

Single regression analysis showed a significant relationship between GL and sex, height, weight, Tegner activity score, IED, CTW, BLL, and LTW. In these parameters, height (R ² = 0.342; B = 1.601; β = 0.588; P < .001) was most predictive of GL. Additionally, GD was significantly correlated with sex, height, weight, IED, CTW, BLL, and LTW. IED (R ² = 0.207; B = 0.030; β = 0.460; P < .001) was most predictive of GD. Stepwise multiple regression analysis determined sex, height, and age as significant predictor variables of GL. This multiple regression model slightly improved the accuracy of accounting for GL, from 34.2% to 38.4% (R ²: from 0.342 to 0.384). Similarly, stepwise multiple regression analysis determined IED and height as significant predictor variables of GD. This multiple regression model also showed slight improvement in the accuracy of accounting for GD, from 20.7% to 22.4% (R ²: from 0.207 to 0.224) (Table 3). The multiple regression model showed the following formulas to predict GL or GD:

\begin{array}{l} GL : 81.122 + 1.208 [Height in cm] - 10.482 \\ [Sex : Male: 1; Female: 2] - 0.235 [Age] \end{array}

GD: 1.758 + 0.020 [IED in mm] + 0.013 [Height in cm]

TABLE 3

Multiple Regression Model for Graft Size Prediction ^a

Dependent Variable	Independent Variable	B	β	P	95% CI
Graft length	Intercept	81.122	—	.034	6.061 to 156.184
R ² = 0.384	Height	1.208	0.438	.000	0.805 to 1.611
	Sex	−10.482	−0.237	.002	−17.033 to −3.930
	Age	−0.235	−0.139	.017	−0.427 to −0.043
Graft diameter	Intercept	1.758	—	.010	0.430 to 3.087
R ² = 0.224	IED	0.020	0.313	.000	0.009 to 0.031
	Height	0.013	0.212	.014	0.003 to 0.024

^a IED, interepicondylar distance.

Discussion

To our knowledge, the current study is the first to derive a regression equation to predict harvested GL and 2-strand GD from anthropometric and radiographic parameters in double-bundle ACLR with ST tendon. The univariate regression model showed that height most accurately predicted GL, while the radiographic parameter (IED) predicted GD more accurately than height. Nevertheless, both parameters had only modest R ² values. The stepwise multivariate regression model showed that height, sex, and age comprehensively predicted GL, and this model slightly improved the accuracy of predicting GL compared with that of the univariate regression model (R ²: from 0.342 to 0.384). Additionally, height and IED on the coronal radiograph also predicted GD comprehensively with slightly improved accuracy (R ²: from 0.207 to 0.224). According to the multiple regression model and our criteria for additional harvesting GT,⁴⁰ (1) height <150 cm, (2) female sex, and (3) patients aged ≥30 years were at risk of having a GL <230 cm, whereas patients who (1) have an IED <70 mm and (2) are <150 cm in height were also at risk of having a GD <5.0 mm.

In relation to the multiple regression model for GL, aging may affect the collagenous degeneration and the fragility of the harvested graft. Thus, the harvested ST tended to be shorter in older patients. The mean harvested GL of the ST was similar that of Chinese patients.⁵² Previous studies have shown that the GL of white patients was longer than that of Chinese patients.^4,47,52 Including our data, Asians have a more diminutive graft size than whites because of physical size differences. According to the regression models in previous studies^4,47,52 as well as the present study, anthropometric factors can predict graft dimensions in both Asian and white populations.^4,47,52 However, comparing the coefficient of determination (R ²) in both races, the regression model was able to predict the graft dimensions more accurately in whites (maximum R ² in GL, 0.48; maximum R ² in GD, 0.41)⁴⁷ than in Asians (maximum R ² in GL, 0.37; maximum R ² in GD, 0.22).^4,52 Thus, racial differences may enable the prediction of graft dimensions according to physical size. Otherwise, anthropometric factors may predict graft dimensions more effectively in patients who have longer or larger skeletal structures.

To our knowledge, little research has been conducted to determine whether radiographic parameters can predict the harvested graft size of the hamstring tendon. The current data show that radiographic parameters are able to predict ST graft length and 2-stranded GD. It is noteworthy that radiographic parameters predicted GD more accurately than anthropometric parameters. Thus, radiographic parameters should be included for predicting ST graft size. Additionally, most previous studies did not mention whether multivariate regression analysis were able to predict GD more accurately. In the current study, the multivariate regression model slightly but significantly improved the accuracy of GD prediction. With regard to our multivariate regression model, both height and IED were selected as significant predictor variables of GD. Future studies can be carried out to predict GD more accurately by combining various parameters in patients who undergo ACLR using hamstring autografts.

Several limitations of the current study must be emphasized. First, only plain radiographs were used for the skeletal measurements, whereas computed tomography or magnetic resonance imaging scans can evaluate skeletal structures in 3 dimensions. In addition, FTA evaluation is more valid when performed using long-standing radiograph. More detailed skeletal evaluations may improve GD predictions. Second, the graft size was affected by surgical skill, and the ST was harvested by several different surgeons.^{32,34,38,46,47,52} Third, the GD was measured by a ready-made cylindrical device that could make measurements in only 0.5-mm increments. Finally, the GL was measured and recorded in 10-mm increments. Despite these limitations, the current study has described a novel method for predicting graft dimensions using anthropometric data and skeletal parameters on a plain radiograph. Future studies warrant detailed mechanisms to predict the GD from the aspect of skeletal morphology.

In summary, the univariate regression model demonstrated that both preoperative anthropometric data and skeletal parameters on a plain radiograph could be used to predict GL and 2-strand graft diameter during primary double-bundle ACL reconstruction using ST. Use of the multivariate regression model slightly improved the GD prediction.

Footnotes

The authors declared that they have no conflicts of interest in the authorship and publication of this contribution.

Ethical approval for this study was obtained from the ethical committee of Hirosaki University Hospital.

Notes

References

Aglietti

Giron

Buzzi

Biddau

Sasso

. Anterior cruciate ligament reconstruction: bone–patellar tendon–bone compared with double semitendinosus and gracilis tendon grafts. A prospective, randomized clinical trial. J Bone Joint Surg Am. 2004;86-A:2143–2155.

Allum

. Complications of arthroscopic reconstruction of the anterior cruciate ligament. J Bone Joint Surg Br. 2003;85:12–16.

Beynnon

Johnson

Fleming

. Anterior cruciate ligament replacement: comparison of bone-patellar tendon-bone grafts with two-strand hamstring grafts. A prospective, randomized study. J Bone Joint Surg Am. 2002;84-A:1503–1513.

Chiang

Wang

Hung

Liu

Chen

. Hamstring graft sizes differ between Chinese and Caucasians. Knee Surg Sports Traumatol Arthrosc. 2012;20:916–921.

Conte

Hyatt

Gatt

Jr Dhawan

. Hamstring autograft size can be predicted and is a potential risk factor for anterior cruciate ligament reconstruction failure. Arthroscopy. 2014;30:882–890.

Ejerhed

Kartus

Sernert

Köhler

Karlsson

. Patellar tendon or semitendinosus tendon autografts for anterior cruciate ligament reconstruction? A prospective randomized study with a two-year follow-up. Am J Sports Med. 2003;31:19–25.

Ellera Gomes

Marczyk

. Anterior cruciate ligament reconstruction with a loop or double thickness of semitendinosus tendon. Am J Sports Med. 1984;12:199–203.

Fanelli

Edson

. Arthroscopically assisted combined anterior and posterior cruciate ligament reconstruction in the multiple ligament injured knee: 2- to 10-year follow-up. Arthroscopy. 2002;18:703–714.

Goldblatt

Fitzsimmons

Balk

Richmond

. Reconstruction of the anterior cruciate ligament: meta-analysis of patellar tendon versus hamstring tendon autograft. Arthroscopy. 2005;21:791–803.

10.

Goyal

Matias

Pandey

Acharya

. Are pre-operative anthropometric parameters helpful in predicting length and thickness of quadrupled hamstring graft for ACL reconstruction in adults? A prospective study and literature review. Int Orthop. 2016;40:173–181.

11.

Hamner

Brown

Jr Steiner

Hecker

Hayes

. Hamstring tendon grafts for reconstruction of the anterior cruciate ligament: biomechanical evaluation of the use of multiple strands and tensioning techniques. J Bone Joint Surg Am. 1999;81:549–557.

12.

Han

Xia

Yun

. Anatomical transverse patella double tunnel reconstruction of medial patellofemoral ligament with a hamstring tendon autograft for recurrent patellar dislocation. Arch Orthop Trauma Surg. 2011;131:343–351.

13.

Hayashi

Kitamura

Kondo

Anaguchi

Tohyama

Yasuda

. Simultaneous anterior and posterior cruciate ligament reconstruction in chronic knee instabilities: surgical concepts and clinical outcome. Knee Surg Sports Traumatol Arthrosc. 2008;16:763–769.

14.

Howe

Johnson

Kaplan

Fleming

Jarvinen

. Anterior cruciate ligament reconstruction using quadriceps patellar tendon graft. Part I. Long-term followup. Am J Sports Med. 1991;19:447–457.

15.

Janssen

RPA

van der Velden

MJF

van den Besselaar

Reijman

. Prediction of length and diameter of hamstring tendon autografts for knee ligament surgery in Caucasians. Knee Surg Sports Traumatol Arthrosc. 2017;25:1199–1204.

16.

Jung

Kim

Park

Bae

. Anatomic reconstruction of the anterior talofibular and calcaneofibular ligaments using a semitendinosus tendon allograft and interference screws. Knee Surg Sports Traumatol Arthrosc. 2012;20:1432–1437.

17.

Kartus

Ejerhed

Sernert

Brandsson

Karlsson

. Comparison of traditional and subcutaneous patellar tendon harvest. A prospective study of donor site–related problems after anterior cruciate ligament reconstruction using different graft harvesting techniques. Am J Sports Med. 2000;28:328–335.

18.

Kautzner

Kos

Hanus

Trc

Havlas

. A comparison of ACL reconstruction using patellar tendon versus hamstring autograft in female patients: a prospective randomised study. Int Orthop. 2015;39:125–130.

19.

Keays

Bullock-Saxton

Keays

Newcombe

Bullock

. A 6-year follow-up of the effect of graft site on strength, stability, range of motion, function, and joint degeneration after anterior cruciate ligament reconstruction: patellar tendon versus semitendinosus and gracilis tendon graft. Am J Sports Med. 2007;35:729–739.

20.

Kleipool

van Loon

Marti

. Pain after use of the central third of the patellar tendon for cruciate ligament reconstruction. 33 patients followed 2-3 years. Acta Orthop Scand. 1994;65:62–66.

21.

Laprade

Wijdicks

. Surgical technique: development of an anatomic medial knee reconstruction. Clin Orthop Relat Res. 2012;470:806–814.

22.

Large

Coley

Peindl

Fleischli

. A biomechanical comparison of 2 ulnar collateral ligament reconstruction techniques. Arthroscopy. 2007;23:141–150.

23.

Lorbach

Haupert

Efe

. Biomechanical evaluation of MPFL reconstructions: differences in dynamic contact pressure between gracilis and fascia lata graft [published online Jan 28, 2016]. Knee Surg Sports Traumatol Arthrosc. doi:10.1007/s00167-016-4005-5

24.

Keifa

Dunn

Harner

. Can pre-operative measures predict quadruple hamstring graft diameter? Knee. 2010;17:81–83.

25.

Maeda

Shino

Horibe

Nakata

Buccafusca

. Anterior cruciate ligament reconstruction with multistranded autogenous semitendinosus tendon. Am J Sports Med. 1996;24:504–509.

26.

Magnussen

Lawrence

West

Toth

Taylor

Garrett

. Graft size and patient age are predictors of early revision after anterior cruciate ligament reconstruction with hamstring autograft. Arthroscopy. 2012;28:526–531.

27.

Mahmoud

Odak

Coogan

McNicholas

. A prospective study to assess the outcomes of revision anterior cruciate ligament reconstruction. Int Orthop. 2014;38:1489–1494.

28.

Mariscalco

Flanigan

Mitchell

. The influence of hamstring autograft size on patient-reported outcomes and risk of revision after anterior cruciate ligament reconstruction: a Multicenter Orthopaedic Outcomes Network (MOON) cohort study. Arthroscopy. 2013;29:1948–1953.

29.

Milano

Mulas

Ziranu

Piras

Manunta

Fabbriciani

. Comparison between different femoral fixation devices for ACL reconstruction with doubled hamstring tendon graft: a biomechanical analysis. Arthroscopy. 2006;22:660–668.

30.

Mott

. Semitendinosus anatomic reconstruction for cruciate ligament insufficiency. Clin Orthop Relat Res. 1983;172:90–92.

31.

Papastergiou

Konstantinidis

Natsis

Papathanasiou

Koukoulias

Papadopoulos

. Adequacy of semitendinosus tendon alone for anterior cruciate ligament reconstruction graft and prediction of hamstring graft size by evaluating simple anthropometric parameters. Anat Res Int. 2012;2012:424158.

32.

Park

Lee

Yoon

. Factors predicting hamstring tendon autograft diameters and resulting failure rates after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2013;21:1111–1118.

33.

Paterson

Trickey

. Anterior cruciate ligament reconstruction using part of the patellar tendon as a free graft. J Bone Joint Surg Br. 1986;68:453–457.

34.

Pichler

Tesch

Schwantzer

. Differences in length and cross-section of semitendinosus and gracilis tendons and their effect on anterior cruciate ligament reconstruction: a cadaver study. J Bone Joint Surg Br. 2008;90:516–519.

35.

Pinczewski

Lyman

Salmon

Russell

Roe

Linklater

. A 10-year comparison of anterior cruciate ligament reconstructions with hamstring tendon and patellar tendon autograft: a controlled, prospective trial. Am J Sports Med. 2007;35:564–574.

36.

Pinheiro

Jr de Andrade

Teixeira

. Intra-operative four-stranded hamstring tendon graft diameter evaluation. Knee Surg Sports Traumatol Arthrosc. 2011;19:811–815.

37.

Sajovic

Vengust

Komadina

Tavcar

Skaza

. A prospective, randomized comparison of semitendinosus and gracilis tendon versus patellar tendon autografts for anterior cruciate ligament reconstruction: five-year follow-up. Am J Sports Med. 2006;34:1933–1940.

38.

Samuelsson

Andersson

Ahldén

Musahl

Karlsson

. Trends in surgeon preferences on anterior cruciate ligament reconstructive techniques. Clin Sports Med. 2013;32:111–126.

39.

Sasaki

Farraro

Kim

Woo

. Biomechanical evaluation of the quadriceps tendon autograft for anterior cruciate ligament reconstruction: a cadaveric study. Am J Sports Med. 2014;42:723–730.

40.

Sasaki

Tsuda

Hiraga

. Prospective randomized study of objective and subjective clinical results between double-bundle and single-bundle anterior cruciate ligament reconstruction. Am J Sports Med. 2016;44:855–864.

41.

Shino

Nakata

Nakamura

Toritsuka

Nakagawa

Horibe

. Anatomically oriented anterior cruciate ligament reconstruction with a bone–patellar tendon–bone graft via rectangular socket and tunnel: a snug-fit and impingement-free grafting technique. Arthroscopy. 2005;21:1402.

42.

Siebold

Chikale

Sartory

Hariri

Feil

Pässler

. Hamstring graft fixation in MPFL reconstruction at the patella using a transosseous suture technique. Knee Surg Sports Traumatol Arthrosc. 2010;18:1542–1544.

43.

Streich

Reichenbacher

Barié

Buchner

Schmitt

. Long-term outcome of anterior cruciate ligament reconstruction with an autologous four-strand semitendinosus tendon autograft. Int Orthop. 2013;37:279–284.

44.

Strobel

Schulz

Petersen

Eichhorn

. Combined anterior cruciate ligament, posterior cruciate ligament, and posterolateral corner reconstruction with autogenous hamstring grafts in chronic instabilities. Arthroscopy. 2006;22:182–192.

45.

Takao

Oae

Uchio

Ochi

Yamamoto

. Anatomical reconstruction of the lateral ligaments of the ankle with a gracilis autograft: a new technique using an interference fit anchoring system. Am J Sports Med. 2005;33:814–823.

46.

Thomas

Bhattacharya

Saltikov

Kramer

. Influence of anthropometric features on graft diameter in ACL reconstruction. Arch Orthop Trauma Surg. 2013;133:215–218.

47.

Treme

Diduch

Billante

Miller

Hart

. Hamstring graft size prediction: a prospective clinical evaluation. Am J Sports Med. 2008;36:2204–2209.

48.

Tsuda

Okamura

Ishibashi

Otsuka

Toh

. Techniques for reducing anterior knee symptoms after anterior cruciate ligament reconstruction using a bone-patellar tendon-bone autograft. Am J Sports Med. 2001;29:450–456.

49.

Tuman

Diduch

Rubino

Baumfeld

Nguyen

Hart

. Predictors for hamstring graft diameter in anterior cruciate ligament reconstruction. Am J Sports Med. 2007;35:1945–1949.

50.

Wernecke

Harris

Houang

Seeto

Chen

MacDessi

. Using magnetic resonance imaging to predict adequate graft diameters for autologous hamstring double-bundle anterior cruciate ligament reconstruction. Arthroscopy. 2011;27:1055–1059.

51.

Williams

3rd Hyman

Petrigliano

Rozental

Wickiewicz

. Anterior cruciate ligament reconstruction with a four-strand hamstring tendon autograft. Surgical technique. J Bone Joint Surg Am. 2005;87(suppl 1 pt 1):51–66.

52.

Xie

Huangfu

Zhao

. Prediction of the graft size of 4-stranded semitendinosus tendon and 4-stranded gracilis tendon for anterior cruciate ligament reconstruction: a Chinese Han patient study. Am J Sports Med. 2012;40:1161–1166.

53.

Yasuda

Ohkoshi

Tanabe

Kaneda

. Quantitative evaluation of knee instability and muscle strength after anterior cruciate ligament reconstruction using patellar and quadriceps tendon. Am J Sports Med. 1992;20:471–475.

54.

Yasumoto

Deie

Sunagawa

Adachi

Kobayashi

Ochi

. Predictive value of preoperative 3-dimensional computer tomography measurement of semitendinosus tendon harvested for anterior cruciate ligament reconstruction. Arthroscopy. 2006;22:259–264.