Effects of lnterference
Fit Screw Length Tibial runnel Fixation For Anterior ruciate Ligament Reconstruction
ABSTRACT
Graft-tunnel mismatch
during Arthroscopically assisted anterigr cruciate ligament reconstruction
using the cen-tral-third patellar tendon results in less than 20 mm of bone
plug remaining in the tibialtunnel. We decided to evaluate the strength of bone
plug fixation using inter-ference fit screws that were less than 20mm in
iength. Biomechanical testing was performed on 48 porcine hindquarters using
9-mm diameter interference fit screws that measured 12.5, 15, and 20 mm in
length. No significant difference was noted between the different-length screws
for insertion torque, divergence, stitf-ness, displacement, or load to failure.
We believe, therefore, that comparable graft fixation can be achieved in the
tibial tunnel using 9-mm diameter interference fit screws that are less than 20
mm long, and that these shorter screws may be useful incases of graft-tunnel
mismatch.
Endoscopic single-incision ACL reconstruction using bone-patellar
tendon-bone autograft has become increasingly popular because of proposed advantages ofdecreased surgical morbidity by a oiding asecond incision and easier postoperatiye posed rehabilitation. Despite these proadvantages, several problems related to graftfixation have been
described, including inaccurate graft placement, divergent screw fixation,
autograft tendon injury, and suboptimal interference screw fixation of the bone
bloek in the tibial tuqnel After the bone plug into the femoral tunael,
mismatch between the length of the graft and the tibial tunnel may leave the
bone plug protruding from the tunnel,. Shortening the effective length of the
plug and potentially is secured compromising strength of the initial
fixation. Although Kenna et al and Lemos et al have recommended that this
problem prevented by understanding the dimensions of the
knee and graft preoperatively and planning the can be an appropriate- length
tibial tunnel, Shiffer et al reported a graft-tunnel mismatch
incidence of 26% in their series of 34 endo-scopic ACL reconstructions. The
incidence in other series is unpublished.
Options or c6rrecting this mismatch are limited. Further recession of the
femoral bone plug risks inaccurate femoral interferenee screw placement and
possible graft abrasion by the femoral tunnel. Shortening the bone plug and
using a standard interference screw risks tendon laceration by the longer
screw. Other options for fixation, including staples or tying sutures in the
tibial bone plug around a post, compromise the initial strength of the
construct in ssmparison with the relatively rigid fixation of an interference
screw. Use of a shorter interference fit screw has not been described in the
clinical literature as a solution to this problem.
Several investigations have been performed to evalu-ate the relationship
between interference screw diame- ter or length and fixation strength. Brown et
al reported no significant effect of screw length on fixation strength for 20-
and 25-mm screws in human cadavers. To the best of
our knowledge, reports of biomechanical testing of
shorter interference fit screws, which may applicable in situations
of graft-tunnel not been published. The purpose mismatch, have
ofthis study was evaluate the failure of 12.5-, 15-, and 20-mm
interfer-ence fit screws.
MATERIALS AND METHODS
Hindquarters were obtained from 48 fresh-frozen pigs weighing between 240
and 260 pounds. Bonepatellar ten-grafts-bone grafts were harvested from each
pig by removing 10 mm diameter tibial bone plugs, leaving the patellar tendon
attached to an intact patella. Each tibial bone plug was noted to have an
approximately 15-mm apophysis proximal to a predominately cortical anterior
tibial crest.The Tibial bone plugwas cut to 13, 15,or 20 mm lengths to
correspond to the length of the cannulated interference screw. The tibial plug
was trimmed into a cylindrical shape to snugly fitthrough a 10-mm sizer with
less than 2mm of space between the plug and the tunnel wall. The tibial plug
was left securely attached to the patellar tendon A No. 2 Ethibond suture
(Ethicon, Somenrille, New Jersey) was passed through the patellar tendon as a
modKessler suture and was used to pull the graft into the l. This was done to
avoid the necessity of creating drill holes in the bone plug and thus weakening
it, as noted by Resnick.
Anteroposterior and lateral radiographs were taken of each specimen to
evaluate angles of divergence and the number of threads engaged. In those
specimens in which the threads of the ssrew did not fully contact
the bone plug, the screw was further advanced and the torque of insertion
was ing again recorded. Repeat radiographs confirmed
firll seat- of the screw. The angle of divergence in both AP and lateral planes
was measured usrng the angle forned bylines tilong the axis of the
tunnel and the screw. The number of threads engaged into the plugwas also
recorded. The patella was mounted in a steel clamp through which a 3-cm, partially
enclosed hole had been made to permit passage of the patellar
tendon. A small, threaded Steinmann pin was passed hrough the proximal aspect
of the cannulated screw and locked onto the screw with a emall nut. The distal
load was applied, therefore, at the proximal end of the screw.
DISSCUSION
Anterior cnrciate ligament reconstruetion has given many athletes the
opportunity to return to their prwious levels of activity with minimal
functional d€ficits. Great advances have been made in understanding the biolory
of placement and the technical pitfalls involved in successfirl
ligament reconstruction. It is generally agreed that the initial weak link'sf
the reconstnrcted knee is at the graft fixatioa site. Consequentfy,
much has been done to investigate tlre factors involved in initial
fixation strength: type of graft, nethod of fixation, interfenence screw
width/core diameter, screw divergence, and torque of insertion Methods of
fixation of insertion.Method of fixation the patellar tendon graft have varied.
Kurosnka et al. demonstrated the superiority 9.0-mm interference
screws compared with 6.5-dnscrews, butbons, and staples. Pull-out strengths of
greater than 400 N have been found in cadaveric studies Using 9-rnm Kurosoka bcrews by Black et al. and Matthews al.,lo and by Bmwn et aI. when
correct€d to the bone density of a young adult. This shength is very close to
the 450 N that Noyes and Grmd stated the normal ACL was exposed t0 during activities of daily living. Compromise of fixation may occur by 1) changing screw specifications or 2) straying recognized
principles in technical insertion.
In conclusion, in this study there was a
positive lation between torque of interference screws
insertion and pull-out strength. There was no significant difference
in torque of insertion, divergence, stiffrress, displacement, or
failure load between 12.5, 15,or 20 mm long cannulated 9mm
interference into porcine bone. We believe,therefore, that shorter
interference corre and fit screws may be used clinically in the
tibial tunnel without compromise ing graft fixation.
DAFTAR PUSTAKA
Aerssens J, Boonen S, Lowet G, et all : Interspesies differences in bone
composition, density, and quality : Potential for in vivo bone research.Endocrinology 139:663-670,
1998.
Kenna B, Simon TM, Jackson DW, et all ;Endoscopic ACL reconstruction : A
technical note on tunnel length for interference fixation. Arthroscopy 9 :
228-230, 1993
Noyes FR, Butler DR,
Grood ES, et all : The strength of the anterior cruciate ligament in humans and
rhesus monkeys : Age related and spesies related changes. J Bone Joint Surg
58A:1074-1082,1976.
My
Analysis :
Jurnal
diatas merupakan salah satu contoh jurnal internasional, dimana jurnal tersebut
berisi tentang pengaruh interference fit screw panjang tibialis anak sungai
kecil fiksasi untuk anterior ruciate ligamen rekonstruksi. Anterior cnrciate ligamen
reconstruetion telah memberikan banyak atlet kesempatan untuk kembali ke
tingkat prwious aktivitas mereka dengan minimal fungsional deficits. kemajuan
besar telah dibuat dalam memahami biolory penempatan dan perangkap teknis yang
terlibat dalam rekonstruksi ligamen successfirl. Hal ini umumnya sepakat bahwa
lemah link'sf awal lutut reconstnrcted adalah di situs graft fixatioa. Consequentfy,
banyak yang telah dilakukan untuk menyelidiki tlre faktor yang terlibat dalam
kekuatan fiksasi awal: jenis korupsi, nethod fiksasi, interfenence lebar sekrup
/ diameter inti, sekrup divergensi, dan torsi Metode penyisipan fiksasi
insertion.Method fiksasi tendon patella graft bervariasi. Kurosnka et al.
menunjukkan keunggulan sekrup gangguan 9.0-mm dibandingkan dengan 6,5-dnscrews,
butbons, dan staples. Tarik-keluar kekuatan yang lebih besar dari 400 N telah
ditemukan dalam studi kadaver Menggunakan 9-RNM Kurosoka bcrews oleh Black et
al. dan Matthews al., lo dan dengan Bmwn et al. ketika benar € d kepadatan
tulang orang dewasa muda. shength ini sangat dekat dengan 450 N yang Noyes dan
Grmd menyatakan ACL normal terkena t0 selama kegiatan hidup sehari-hari.
Kompromi fiksasi dapat terjadi oleh 1) mengubah spesifikasi sekrup atau 2)
menyimpang prinsip yang diakui dalam penyisipan teknis. Dalam penelitian ini
ada lation positif antara torsi gangguan sekrup penyisipan dan tarik-keluar
kekuatan. Tidak ada perbedaan yang signifikan dalam torsi penyisipan,
divergensi, stiffrress, perpindahan, atau beban kegagalan antara 12,5, 15, atau
20 mm panjang cannulated 9mm gangguan dalam tulang babi. Kami percaya, karena
itu, bahwa gangguan corre pendek dan sekrup fit dapat digunakan secara klinis
di terowongan tibialis tanpa kompromi ing fiksasi graft.
Sekian analisa dari saya, mohon
maaf apabila ada kekurangan dalam pemahaman jurnal ini karena saya juga masih
dalam tahap pembelajaran. Terima Kasih.