From the Department of Orthopaedics, Graduate School of Medicine, Kangwon National University, Chuncheon, Korea

Transcription

1 Act Orthop. Belg., 2016, 82, ORIGINAL STUDY Supplementry tiil fixtion in nterior crucite ligment reconstruction Direct corticl fixtion using spiked wsher screw vs. post-tie using wsher screw Jung Ho Noh, Hee Soo Kyung, Kyoung Ho Yoon, Young Hk Roh From the Deprtment of Orthopedics, Grdute School of Medicine, Kngwon Ntionl University, Chuncheon, Kore We compre clinicl outcomes of two different supplementry tiil fixtion in nterior crucite ligment (ACL) reconstruction using free tendon Achilles llogrft. Eighty sujects underwent ACL reconstruction using Endoutton CL for femorl fixtion nd Bio-interference screw for tiil fixtion. Supplementry tiil fixtion ws performed s direct corticl fixtion using spiked wsher screw (group I) or s post-tie using wsher screw (group II). Lchmn test, pivot shift test, IKDC clssifiction, Lysholm score, nd side-to-side difference (SSD) were evluted. Thirty six in group I nd thirty five in group II could follow up for t lest 2 yers. At the lst followup, 7 in group I nd 1 in group II showed 2+ or 3+ in Lchmn test (p = 0.027). Men SSD ws 2.4mm in group I nd 1.4mm in group II (p = 0.048). Post-tie using wsher screw ws more effective thn direct corticl fixtion using spiked wsher screw to restore stility. Level of evidence : Therpeutic Level I ; Rndomized controlled clinicl tril. Keywords : nterior ; crucite ; ligment ; reconstruction ; Achilles ; post-tie ; spiked wsher. INTRODUCTION As incidence of nterior crucite ligment (ACL) injury increses, the numer of reconstruction of ACL rpidly increses s well. Bone-ptellr tendon-one grft hs een widely used, however, usge of Achilles tendon llogrft grdully increses due to concerns over moridity t donor site. In the pst, the outcomes of one-to-one fixtion were etter thn those of soft tissue-to-one fixtion, however, the outcomes of ACL reconstruction using soft tissue grft hve een improved with development of technology nd technique of fixtion through iomechnicl studies (12,9,24). Pullout strength t metphysel one in tii hs een reported less thn tht in femur from mny iomechnicl studies (25). The resons re tht the ony structure of the tiil metphysis is less dense n Jung Ho Noh, MD, PhD. Deprtment of Orthopedics, Grdute School of Medicine, Kngwon Ntionl University, Chuncheon, Kore. n Hee Soo Kyung, MD, PhD. Deprtment of Orthopedics, School of Medicine, Kyungpook Ntionl University, Degu, Kore. n Kyoung Ho Yoon, MD, PhD. Deprtment of Orthopedics, School of Medicine, Kyunghee Ntionl University, Seoul, Kore. n Young Hk Roh, MD, PhD. Deprtment of Orthopedics, School of Medicine, Gchon Ntionl University, Incheon, Kore. Correspondence : Young Hk Roh, Deprtment of Orthopedic Surgery, Gil Medicl Center, Gchon University School of Medicine 1198 Kuwol-dong, Nmdong-gu, Incheon , Kore. E-mil : ryhk@hnmil.net 2016, Act Orthopædic Belgic. No enefits or funds were received in support of this study. The uthors report no conflict of interests. noh-roh-.indd /06/16 14:36

2 359 j. h. noh, h. s. kyung, k. h. yoon, y. h. roh thn tht of the femorl metphysis nd tht the direction of pullout force of the grft is prllel to the tiil tunnel, while it is usully ngled to the femorl tunnel (5,6,14). The softer cncellous one in the tii impirs the grip of fixtion devices tht primrily engge cncellous one, such s the interference screw (7). Poor fixtion my increse the chnce of residul lxity nd often led to unstisfctory outcomes of opertion. Sufficient stiffness of grft fixtion llows erly moiliztion nd lessens the residul lxity (23). In tiil tunnel, soft tissue grfts re usully fixed with interference screw nd stple or spiked wsher screw is often used for supplementry fixtion on tiil cortex to improve stiffness of the grft construct (13,30,26). These dditionl fixtions often cuse prolems due to considerle profile t fixtion site nd irrittion of soft tissue coverge especilly with spiked wsher screw or stple. Furthermore, there my lso remin the residul lxity even with the supplementtion. The purpose of this study ws to compre the clinicl outcomes of two different supplementry fixtion methodology in ACL reconstruction using free tendon Achilles llogrft with iodegrdle interference screw in the tiil tunnel ; direct corticl fixtion using spiked wsher screw versus post-tie using wsher screw. The null hypothesis of this study ws tht the clinicl outcomes of the ACL reconstruction with supplementry tiil fixtion were not significntly different etween two groups ; direct corticl fixtion with spiked wsher screw versus post-tie fixtion with wsher screw. Sujects MATERIALS AND METHODS A prospective, rndomized, comprtive study ws conducted with the pprovl of ethics committee of our institution during June 2009 to April A totl of 130 sujects were dignosed with ACL injuries. Sujects who hd medil collterl ligment injury which hd een treted conservtively or meniscus ter which ws mnged y prtil meniscectomy were included. Sujects who hd meniscus repir, sutotl or totl meniscectomy, other ligment injuries which need surgeries other thn ACL, ny injury on ipsilterl leg other thn knee, previous injury on contrlterl leg, nd full thickness crtilge dmge which needs microfrcture, multiple drilling, osteochondrl utogrft, or utogenous chondrocyte implnttion were excluded. Thirty one sujects were excluded nd 4 sujects refused opertion. Among them who met the inclusion criteri, 15 sujects refused to prticipte in the study. Eighty sujects were recruited nd informed consents for the surgery nd study were otined. Demogrphics of the sujects re presented in Tle I. All the sujects were dignosed y physicl exmintion nd MRI, nd were confirmed y rthroscopy. Lchmn test nd pivot shift test were conducted under nesthesi efore reconstruction. The sujects were grouped y computer generted rndomiztion : 40 in group I nd 40 in group II. The ACL ws reconstructed using free tendon Achilles llogrft fixed with Endoutton CL (Smith & Nephew, Endover, MA, USA) in femorl tunnel nd Bio-interference screw (Arthrex, Nples, FL, USA) in tiil tunnel, which ws ugmented on tiil cortex with direct corticl fixtion using spiked wsher screw (group I) or post-tie using wsher screw (group II). Surgicl technique Tiil tunnel ws mde t footprint or 7 mm nterior to posterior crucite ligment with the ngle of 45 degrees to the tiil shft. Femorl tunnel ws mde t footprint vi nteromedil portl with the knee flexion of 120 degrees or more. The size of the remer for the tiil nd femorl tunnels ws 9 mm. The fresh frozen Achilles tendon llogrft ws thwed t room temperture. Clcnel one lock ws removed with the ttched tendon preserved. It ws usully seprted y mnul tension without difficulty. The free tendon ws folded into two-strnd grft nd ws trimmed to e 9-mm thick. The length of the two-strnd grft ws set to e cm for group I nd cm for group II. The grft ws looped over the Endoutton CL with the pproprite length nd 20 mm of looped end of the grft ws whipstitched with No.1 Vicryl (Ethicon, Somerville, NJ, USA). Three centimeters of ech of the two free ends ws whipstitched with No.2 Ethiond (Ethicon, Somerville, NJ, USA) nd ech of two strings on ech free end of the grft ws retined. The looped end ws mrked t the position where it ws to e seted in the femorl socket to ensure tht the grft ecme completely seted in the femorl socket y rthroscopy. Twenty to twentyfive millimeters of looped end of the grft ws inserted into femorl tunnel vi tiil tunnel. Before tiil fixtion, 20 times of full rnge of knee motion cycles under mximl mnul lod were conducted for pretensioning. noh-roh-.indd /06/16 14:36

3 wsher screw 360 Tiil tunnel ws fixed with 7*23 mm or 8*23 mm Biointerference screw. After drilling t 1-2 cm distl to the nterior perture of tiil tunnel, in group I, the free ends of the grft were fixed with spiked wsher under mnul tension. In group II, ech two slinging sutures on the ends of the strnds were tied together round the wsher screw. Postopertive rehilittion Qudriceps strengthening exercise ws performed immeditely fter the surgery, prtil weight ering ws llowed on the third dy nd full weight ering ws llowed s tolerted. Continuous pssive motion (CPM) exercise ws egun on the second postopertive dy, nd it ws llowed up to 90 degrees of flexion until the fourteenth dy, 120 degrees until the sixth week, nd full rnge of motion fterwrd. After 12 weeks, jogging nd sttionry icycling were llowed. After 6 months, sujects were llowed to do competitive sports except for those exercises tht might involve strong contcts with others such s footll or soccer, or those exercises tht might impose strong externl forces on the sujects knee such s skiing or snowording. All kinds of exercises were llowed fter 9 months. Assessment of outcomes Lchmn test nd pivot shift test were grded ccording to the IKDC 2000 criteri nd were evluted y two orthopedic surgeons tht re independent to the surgery preopertively nd t the lst follow-up. IKDC clssifiction nd Lysholm score were evluted preopertively nd t the lst follow-up. Rnge of motion of the reconstructed knee ws compred to tht of uninjured knee t the lst follow-up. Tegner ctivity scle ws evluted efore injury nd t the lst follow-up. Stress rdiogrphs were tken while ech knee ws in flexion of 30 degrees nd ws loded 150N using Telos stress device (Austin & Associte Inc., Fllston, MD, USA) preopertively nd t the lst follow-up. Side-to-side difference (SSD) ws mesured y two orthopedic surgeons using picture rchiving nd communiction system (GE Helthcre, Chicgo, IL, USA). Single-leg hop test (SLH) ws performed t the lst follow-up, in which the mximl distnce out of three trils ws dopted nd nlyzed s percentge of tht of uninjured leg. Sttisticl nlysis The sttisticl nlyses of differences in continuous vriles etween two groups were performed with student t test nd differences in ctegoricl vriles with Mnn-Whitney U test, chi-squre test, nd Wilcoxon signed rnk test. Interoserver nd introserver reliility ws ssessed y intrclss correltion coefficient (ICC) with the respective 95% confidence intervls. SPSS version 17.0 (SPSS Inc., Chicgo, IL, USA) ws used for sttisticl nlyses. The minimum level of significnce ws Tle I. Demogrphics Vriles Group I (n = 40) Group II (n = 40) P Type of supplementry fixtion Direct corticl fixtion using Post-tie using wsher screw spiked wsher screw Men ge (yers) (± SD ) 28.3 ± ± Mle:femle 34:6 35: c Lterlity (right:left) 18:22 16: c Men BMI (kg/m 2 ) (± SD ) 23.3 ± ± Men period from injury to opertion (weeks) (±SD ) 8.5 ± ± Mechnism of injury c Sports Fll down 4 6 Trffic ccident 4 5 Unknown 1 0 Stndrd devition. Student t test. c Chi squre test. noh-roh-.indd /06/16 14:36

4 361 j. h. noh, h. s. kyung, k. h. yoon, y. h. roh Tle II. Lchmn test, pivot shift test, nd IKDC clssifiction t the lst follow-up Group I (n = 36) Group II (n = 35) P Lchmn test negtive 23 (63.9%) 29 (82.9%) 1+ 6 (16.7%) 5 (14.3%) 2+ 7 (19.4%) 1 (2.9%) 3+ 0 (0%) 0 (0%) Pivot shift test negtive 25 (72.2%) 29 (82.9%) 1+ 7 (19.4%) 4 (11.4%) 2+ 4 (11.1%) 2 (5.7%) 3+ 0 (0%) 0 (0%) IKDC clssifiction A 20 (55.6%) 26 (74.3%) B 9 (25.0%) 7 (20.0%) C 7 (19.4%) 2 (5.7%) D 0 (0%) 0 (0%) Chi squre test. RESULTS Thirty six in group I nd 35 in group II followed up for t lest 2 yers. Eight sujects were lost to follow up nd one suject hd re-injury to the sme knee during soccer nd ws excluded. Interoserver ICCs for Lchmn test, pivot shift test nd SSD were over 0.8 nd introserver ICC for SSD ws Preopertive Lchmn test ws grde 2 or 3 in ll sujects. At the lst follow-up, seven (19.4%) in group I nd one (2.9%) in group II showed grde 2 or 3 on Lchmn test (p = 0.027). Four (11.1%) in group I nd two (5.7%) in group II showed grde 2 or 3 on pivot shift test t the lst follow-up. (p = 0.414) All sujects showed C or D in IKDC clssifiction preopertively. Twenty nine (80.6%) in group I nd thirty three (94.3%) in group II showed A or B in IKDC clssifiction t the lst follow-up (p = 0.082) (Tle II). Men Lysholm score ws 59.5 ± 8.1 preopertively nd 92.2 ± 4.6 t the lst follow-up (p < 0.001) (Tle III). One suject in group I nd two sujects in group II showed limittion of motion compred to the other knee (p = 0.539) nd ll of those were 5 degrees or less. Medin Tegner ctivity scle ws 7 (rnge, 5-9) efore injury nd 6 (rnge, 4-9) t the lst follow-up (p = 0.001) (Tle IV). Men SSD ws 9.8 ± 4.0mm preopertively nd 2.1 ± 2.2mm t the lst follow-up (p < 0.001) (Tle V). The verge vlue on SLH ws 88.5 ± 5.7% in group I nd 90.4 ± 5.0% in group II compred to the other knee t the lst follow-up (p = 0.127). Twenty seven sujects (75.0%) in group I nd six (17.1%) in group II complined of irrittion of soft tissue or tenderness on the ump t the site of supplementry fixtion during follow-up (p < 0.001). All of their fixtives were removed t lest one yer fter surgery nd the complints did not lst ny longer. Any other complictions were not oserved during the follow-up period in either group. DISCUSSION The results of this study showed sttisticlly significnt differences in Lchmn test (negtive or 1+ vs. 2+ or 3+) nd SSD etween two groups lthough the other clinicl outcomes of oth groups were not significntly different. Fixtion methods in ACL reconstruction re lrgely divided into three ctegories including compression (eg. metl or noh-roh-.indd /06/16 14:36

5 wsher screw 362 Tle III. Men Lysholm score Preopertive Lst follow-up Group I Group II P Group I Group II P Lysholm score ( ± SD ) 59.8 ± ± ± ± Stndrd devition. Student t test. Tle IV. Medin Tegner ctivity scle Pre-injury Lst follow-up Group I Group II P Group I Group II P Tegner ctivity scle (rnge) 7 (5-9) 7 (5-9) (4-8) 6 (4-9) Mnn-Whitney U test. Wilcoxon signed rnk test. Tle V. Men SSD on Telos stress device Preopertive Lst follow-up Group I Group II P Group I Group II P SSD (mm) (± SD ) 9.7 ± ± ± ± Stndrd devition. Student t test. iodegrdle interference screw), expnsion (eg. Rigidfix), nd suspension (eg. Endoutton, Endoperl, Trnsfix, or Bone mulch). The results of soft tissue-to-one fixtion with metl or iodegrdle interference screw hs een demonstrted s not very promising in mny studies (1,10,17). Although its fixtion strength in outside-in technique my e somewht etter, fixtion strength in tiil tunnel is less thn tht in femorl tunnel, nd it my not e enough to er stress regrding tht norml dily lod in the intct ACL is pproximtely 450N (19,20). Mgen et l (16) reported tht the filure lod of interference screw, which ws 350N, ws not enough in tii. Wng et l (27) reported tht the grft slipped out 7 mm under 400 N lod in the study of the fixtion strength of the iodegrdle interference screw in tiil tunnel. Weimnn et l (29) reported tht the grft slippge ws 4.1 mm fter 1000 cyclic lod of 250 N. In ddition to interference screw fixtion in tiil tunnel, ugmenttion with stple or spiked wsher is often conducted due to its less stle fixtion (13,30,26). Ngrktti et l (21) showed tht ugmenting soft tissue fixtion on tiil tunnel with n nchor of polylctic cid ll or corticl one disk significntly incresed the stiffness of the construct. Weiler et l (28) showed tht supplementtion of interference screw fixtion of soft tissue grft with n Endoperl device incresed pullout strength from ± N to 658 ± N nd incresed stiffness from ± 8.47 N/mm to 41 ± 11 N/mm. However, direct corticl fixtion of the grft with spiked wsher screw hs high profile, so ump under the skin my e mjor disstisfction for the sujects. Furthermore, the uthors hve often experienced screw loosening during tightening the spiked wsher screw to firmly fix the grft. Sometimes, cutting off suture y spike or shrp mrgin of the spiked wsher lso hppens. Grft slippge often cnnot e prevented even though supplementry fixtion to the tiil end using spiked wsher nd the outcomes my e disppointing due to considerle residul lxity (8). There hve een few studies compring fixtion strength etween direct corticl fixtion with spiked wsher screw nd post-tie with wsher screw. This study showed tht post-tie with tethering sutures t noh-roh-.indd /06/16 14:36

6 363 j. h. noh, h. s. kyung, k. h. yoon, y. h. roh ech free end of looped grft contriuted stisfctory outcomes in terms of residul lxity compred to direct fixtion of the grft to the tiil cortex with spiked wsher screw. Lee et l (15) reported tht supplementry fixtion with stple or push-lock screw did not increse the structurl strength nd stiffness of the soft tissue grft fixtion with iodegrdle interference screw in porcine knee. However, this my not e pplied to clinicl sitution nd fixtion strength of interference screw is greter in porcine knee s it is denser thn humn knee. Moreover, one minerl density in the proximl tii decreses fter ACL injury (3,4). Biley et l (2) reported tht the properties of interference screw fixtion for soft tissue grft in porcine tii were overestimted compred with young humn tii. Hill et l (10) reported tht supplementry stple fixtion on tii ws effective to reduce nterior displcement of the tii. Six weeks of performing the ctivities of dily living corresponds to pproximtely 220,000 cycles to the ACL t tensile lod of 169 N (19). Tensile strength of No. 2 ethiond, which is out 120 ~ 130 N (11), is reltively less thn the stress to the ACL in dily living ctivity. Miller et l (18) reported tht the filure lods of orthocord, fierwire nd mnrid were superior to tht of the ethiond in mechnicl study for suture mteril. It my e more secure if these mterils re used insted of ethiond. However, the numer of sutures t the end of ech strnd is totlly four nd the post-tie is supplementry to first line fixtion using interference screw, therefore the uthors do not think this would e n issue. Five to ten millimeters of the tiil end of the grft ws left out of tunnel to prevent suture cut y shrp mrgin of the tiil tunnel entrnce. Further studies re needed to clrify whether this method is helpful in preventing rupture of suture mteril. A screw with no thred out 5mm next to the hed of screw ws used nd post-tie ws performed fter insertion of the threded portion of the screw into the one to prevent suture cut y thred of the screw. Bsed on the results of this study, the null hypothesis hs een ccepted, nd there re lso enefits to conduct post-tie using wsher screw rther thn direct corticl fixtion using spiked wsher screw in terms of profile nd costs while expecting good outcomes. This study hs few limittions. First, the follow-up period ws short. Second, the uthor did not distinguish etween the femorl side nd the tiil side s cuse of the residul lxity. The grft ws fixed with Endoutton CL in the femorl side to minimize the slippge, however further study would e needed to identify whether the residul lxity during follow-up is due to slippge on tiil side or not. Third, there ws no control group to show tht supplementtion would e etter option for tiil fixtion. Controversy my still exists whether supplementtion is necessry in ddition to interference screw. However, Noh et l (22) previously reported tht the supplementry tiil fixtion ws helpful in restortion of the stility. At lest, post-tie would e etter option thn direct corticl fixtion using spiked wsher screw if supplementtion would hve een pplied. CONCLUSIONS Post-tie using wsher screw s supplementry tiil fixtion in ACL reconstruction ws more effective thn direct corticl fixtion using spiked wsher screw to restore stility. Post-tie using wsher screw my e recommended regrding reltively lower profile t the fixtion site. Acknowledgement This study ws supported y 2013 Reserch Grnt from Kngwon Ntionl University. REFERENCES 1. Ahmd CS, Grdner TR, Groh M, Arnouk J, Levine WN. Mechnicl properties of soft tissue femorl fixtion devices for nterior crucite ligment reconstruction. Am J Sports Med 2004 ; 32 : Biley SB, Grover DM, Howell SM, Hull ML. Fomreinforced elderly humn tii pproximtes young humn tii etter thn porcine tii : study of the structurl properties of three soft tissue fixtion devices. Am J Sports Med 2004 ; 32 : Bk K, Jorgensen U, Ekstrnd J, Scvenius M. Results of reconstruction of cute ruptures of the nterior crucite ligment with n iliotiil nd utogrft. Knee Surg Sports Trumtol Arthrosc 1999 ; 7 : noh-roh-.indd /06/16 14:36

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