SELECTIVE BUNDLE RECONSTRUCTION IN PARTIAL ANTERIOR CRUCIATE LIGAMENT

Salama m.i, el elesh h.m, el mesallamy s.h and el attar m.s. Orthopaedic Surgery Department, Zagazig University Hospitals, Egypt. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 12 September 2018 Final Accepted: 14 October 2018 Published: November 2018


ISSN: 2320-5407
Int. J. Adv. Res. 6(11), 997-1010 999 Examination. All patients underwent careful examination before the operative procedure. A partial ACL injury was suspected in patients having a positive Lachman test grade I or II with hard endpoint, With negative Pivot shift test or only slight glide and was confirmed intraoperatively by examination under anethesia. Confirmation of partial ACL tear was done arthroscopicly.
Imaging: Plain X-ray. Weight bearing AP and lateral views were done to all patients and showed to be normal. Radiographic evaluation was done according to the IKDC recommendations.

MRI.
All patients were evaluated by doing MRI that showed partial tear of ACL in some cases. In other cases,the ACL appear normal with no evidence of interuption . Confirmation of other ligaments integraity were intact. Meniscal injuries were diagnosed also.

Operative technique:
All operations were performed under spinal anesthesia, under a well padded thigh tourniquet. Examination under anesthesia was done for all patients to ensure partial ACL tear by positive Lachman with hard endpoint and negative pivot shift tests. All patients were given one gram ceftriaxone intravenously 30 minutes before the operation.
Routine diagnostic arthroscopy was initially performed to ensure diagnosis of partial ACL tear and detect which bundle was torn AM or PL and evaluate other pathological conditions. Any meniscal problems were treated before proceeding of reconstruction of torn bundle. Debridement of torn bundle was done leaving intact bundle.

Preparation of the graft:
The tendon was taken to the graft station. The muscle fibers were removed using scalpel or scissor taking care not to cut the tendon itself. The tendon was folded in a double loop. Each one of the free ends of the tendon was stitched 1000 separately by Ethibond suture no. 2 that was woven in an ascending to descending fashion to secure the loop ends firmly for a distance of 2 cm (Fig 39)

Portals:
The procedure is done using three arthroscopic portals. The anterolateral for viewing during diagnostic arthroscopy, the anteromedial portal used as viewing portal and the accessory medial portal for drilling of femoral tunnel (fig 3). The femoral tunnel was drilled first before the tibial tunnel.

2.
The arthroscope was switched to the (AM) portal for viewing the medial wall of the lateral femoral condyle.

3.
A micro fracture awl was inserted through the (AAM) portal and used to mark the location of the PL bundle footprint which is located an average of 5 mm posterior to the shallow articular cartilage of the lateral femoral condyle.

4.
A 2.7 mm guide pin was inserted through the (AAM) portal to the mark of femoral tunnel location and drilled through the bone exiting the lateral cortex while the knee was in 110° of flexion ( fig.4 ).

Fig 4:
-Guide pin insertion 5. The femoral tunnel was drilled through the femoral cortex using a 4.5 mm endobutton drill bit, during reaming a curette was inserted through antero lateral portal to protect AM bundle 6. The femoral tunnel length was calculated using a special depth gauge to calculate the length of endobutton loop ( fig.5). The femoral tunnel was drilled using an endoscopic drill bit according to diameter of the graft and length of the femoral tunnel leaving at least 6-7 mm of the lateral femoral cortex intact. 8. A #2 vicryl suture was loaded into the slotted end of the 2.7 mm guide pin and the free ends of the suture were passed out through the lateral soft tissue, leaving the looped end of the suture in the ACL femoral tunnel.
The arthroscope was switched to the (AL) portal with the knee flexed to 70-90 degree.

2.
An AcuFex director ACL tip aimer was set at a 55° angle through (AM) or (AAM) portal into knee joint. 3.
The tip of the aimer was positioned in the PL part of the tibial ACL insertion an average of 4-5 mm medial to the lateral intercondylar eminence and 4-5 mm anterior to the posterior root of the lateral meniscus ( fig.6).
1002  The femoral tunnel was drilled first before the tibial tunnel.

2.
The arthroscope was switched to the (AM) portal for viewing the medial wall of the lateral femoral condyle. A 2.7 mm guide pin was inserted through the (AAM) portal to the mark of femoral tunnel location and drilled through the bone exiting the lateral cortex while the knee was in 110° of flexion. 5.
The femoral tunnel was drilled through the femoral cortex using a 4.5 mm endobutton drill bit, during reaming a curette was inserted through anterolateral portal to protect PL bundle. 6.
The femoral tunnel length was calculated using a special depth gauge to calculate the length of endobutton loop. 7.
The femoral tunnel was drilled using an endoscopic drill bit according to diameter of the graft and length of the femoral tunnel leaving at least 6-7 mm of the lateral femoral cortex intact ( fig.9) A #2 vicryl suture was loaded into the slotted end of the 2.7 mm guide pin and the free ends of the suture were passed out through the lateral soft tissue, leaving the looped end of the suture in the ACL femoral tunnel.
The arthroscope was switched to the (AL) portal with the knee flexed to 70-90 degree.

2.
An AcuFex director ACL tip aimer was set at a 55° angle through (AM) or (AAM) portal into knee joint. 3.
The tip of the aimer was positioned in the AM part of the tibial ACL insertion 4-5 mm lateral to the medial tibial spine of the medial tibial plateau and 4-5 mm posterior to the anterior rim of the ACL footprint.  The anterior border of the ACL insertion is carefully preserved to avoid anterior intercondylar roof impingement, damage to the transverse intermeniscal ligament and damage to the articular cortical bone or the articular cartilage. A guide wire is overdrilled by a conventional reamer according to the size of the AM graft preserving the intact insertion of the PL bundle.
Graft passage: 1. An arthroscopic probe or grasper was used to retrieve the suture loop that was left in the ACL femoral tunnel and the suture loop was pulled out through the tibial tunnel.

Rehabilitation:
Postoperatively, all patients followed the accelerated rehabilitation program of Shelbourne and Nitz using a CPM machine.

Follow up:
Visits were conducted 2 weeks,one and half month, 3 months, 6 months and one year and every one year after. At each visit, patients were assessed both clinically using lysholm and IKDC.

Statistical analysis:-
The collected data were computerized and statistically analyzed using SPSS program (Statistical Package for Social Science) version 18.0.Qualitative data were represented as frequencies and relative percentages.Quantitative data were expressed as mean ± SD (Standard deviation).
Paired sample T test was used to calculate difference between quantitative variables in the same group pre and post therapy in normally distributed data. Paired Willicoxon test was used to calculate difference between quantitative variables in the same group pre and post therapy in not normally distributed data.
The significance Level for all above mentioned statistical tests done. The threshold of significance is fixed at 5% level (P-value) 1. *P value of >0.05 indicates non-significant results. 2. *P value of <0.05 indicates significant results. 3. *P value of <0.01 indicates highly significant results.
1006 Results:-Assessment by lysholm score Regarding overall outcome of all patients in the study, the preoperative score was of a mean value of 64.9 and standard deviation of 9.07. The postoperative score at 6 months was of a mean value of 95.3 and standard deviation of 3.4 The improvement of the lysholmscore at 6 months postoperatively was statistically highly significant with P value < 0.001.

Complications:
Among 30 cases in our study, two patients had superficial wound infection at graft site, one patient has touniqet neuropaxia, three patient had neuropraxia of saphenous nerve and its infrapatellar branch and one patient has hemoarthrosis The complication rate in our study is 23.33%. All cases showed complete recovery on postoperative rehabilitation programs and conservative therapy.

Discussion:-
In this study, we had a 30 cases were subjected to diagnostic knee arthroscopy. The arthroscopic findings were as the following: 22 patients had posterolateral bundle tear and 8 patient had anteromedial bundle tear.
Partial anterior cruciate ligament (ACL) tears make up10-28% of all ACL tears .There is no consensus on the definition of a partial ACL tear. However, most authors agree that partial ACL tear is one that combines a positive Lachman's test with a firm endpoint along with small differential laxity, hyperintense signal within the ACL fibers on MRI, and arthroscopic findingsof a partial tear. Noyes (6) defined it according to the percentage of ACL remaining, Crain (7) using an arthroscopic assessment, and DeFranco and Bach (8) based on a combination of clinical, knee laxity and arthroscopic criteria (9) .
Partial ACL lesions represent a challenging pathology. The current international literature agrees on the need to spare the intact bundle of the partially torn ACL to increase the biomechanical strength of the reconstruction in the early postoperative period and to maintain ACL blood supply and proprioception. Many authors have described augmentation techniques to restore knee kinematics, thus maintaining the ACL remnant. Most techniques are 1008 intended to obtain an anatomic reconstruction of the torn bundle. This surgery is technically challenging, requiring adapted portals, perfect control of the instruments during tunnel reaming, and intercondylar space management, which is crucial, especially when dealing with small knees (10) .
In our study, instability of the knee is the main complaint 27 patients had frequent giving way (90%).Pain in the knee related to activiy was a cardinal complaint almostly in all patient in our study. Eleven patient had locking sensation (36.6%) , 7 patients had swelling of knee in ordinay exertion (23%) and 18 patients had swelling in sever exertion (60%).Postoperative instability show significant improvement with no giving way in 26 patients (86.6%) and 4 patients rarely giving way in sever exertion (13.4%) .Postoperative pain show significant imrovement in 22 patient (73.3%).Postoperative locking sensation showed significant improvement in 29 patients(96.7%). Postoperative swelling were significant improvement in 25 patients (83.3%).Those results of our study are close to Pyjol 15) , who had 29 patients in his studty 16 male and 13 female . The averge age was 31years .All 29 patient AM bundle tear. Follow up continues 12 months . Preoperatively 25 patients had instability (86.3%). 17 patients (48.%) had pain in the knee related to activity. 6 patients (20.6%) had locking sensation in the knee. Five patients had swelling of knee in ordinay exertion (17.2%) and 14 patients had swelling in sever exertion (48.2%). Postoperatvely instability show significant improvemet in all patients. Postoperative pain showed significant improvement in 14 patients. Also, locking sensation and swelling showed significant improvement in all patients.
The results for objective score have shown improvement of Lachman test and pivot shift test. The pivot shift test preoperatively was grade 0 in 12 patients (40%),grade I in 16 patients (53.3%)and grade I I in two patients (6.7%), while postoperatively, 29 patients (96.7%) were grade 0 and 1 patients (3.3%) were grade I. Lachman test preoperatively was 8 patients (26.7%) being grade I and 22 patients(73.3%)being grade II, while postoperatively, 26 patients (86.7%) were grade 0 and 4 patients (13.3%) were grade I. Close to Sonnery Cottet (14) , ,preoperatively all 39 patients had Lahman test grade II with hard endpoint , pivot shift test in 34 patients grade I, 3 patients grade II and two patient grade III . Postoperatively 32 patients Lachman test grade 0 and 7 patients grade I, povit shift test 35 patients were grade 0 and 4 patients were grade I. Lysholm knee scoring system was utilized to assess the results of this study,it was used for subjective evaluation .The total score showed significant improvement from 64.9 points(SD±9.07) preoperatively to 95.3 points (SD±3.4) postoperayively.
1009 IKDC was utilized to assess the results of this study it was used for objective evaluation; before surgery, 3 patients had abnormal IKDC grade (B), 22 patients had abnormal IKDC grade (C) and 5 patients had severely abnormal grade (D). After surgery, 26 patients had normal IKDC grade (A) and 4 patients had nearly normal grade (B) . Close to Sonnery Cottet (14) , who had 39 patients and followed up for 2 years preoperative 17 grade B ,21 grade C and one patient grade D, postoperative 34 grade A and 5 grde B.Superior to results of Sabat (13) , , who had 38 patients and followed up for three years before surgery 8 grade B ,26 grade C and 4 patients grade D, postoperative 12 grade A ,25 grde B and one grade C.
The result of our study were comparable with the results of Sonnery Cottet (14) , in his study Lysholm score improved from 60.8 points preoperatively to 94.2 points postoperatively. The two studies had a similar number of patients, mean age, similar technique and same tibial and femoral fixation.
The results in our study is close to the result of Abat (12) , who had 28 patient, mean age (30.4 years), 21 male and 7 female, 18 patient AM bundle tear, 10 patient PL bundle tear. Follow up continued for 37 months. In his study Lysholm score improved from preoperative 65.4 points preoperative to 95.8 points postoperative. This may be due to two studies had similar number of patients, mean age and small number of female patient .
The result in our study are superior to the results of Pyjol (15) , who had 29 patients, 16 male and 13 female, mean age 32 years with all 29 patients having AM bundle tear. In their study, mean Lysholm score improved from 69.9 points preoperative to 90.8 points postoperative at one year follow up. That may be due to the large number of female patients in his study 13 female (44.8%) but in our study only two female patient (6.6 %). All patients in Pyjol (15) had AM bundle tear but in our study 22 patients had PL bundle tear and 8 patients had AM bundle tear. In our study all femoral tunnel were done through accessory medial portal, femoal fixation were done by endbutton and tibial fixation by interferance screw but in Pyjol (15) , femoral tunnel were done by outside in, accessory medial portal and transtibial, femoral fixation by interferance screw and endbutton, tibial fixaton by interferance screw and douple fixation. The variety of fixation and technique may worse the results. (17) compared graft revascularization during a standard ACL reconstruction with removal of the torn ACL remnant to selective bundle ACL reconstruction with retention of the preserved bundle L.Using this MRI protocol, they showed that preservation of ACL remnant leads to earlier revascularization at 2months and a significant reduction of ACL graft signal at 6 months within the midsubstance of the ACL graft.

Gohil et al
In my study there are several limitations. The sample size is small 30 patients and the study group is heterogenous regarding age and chronicity of injury. Due to a lack of a comparative group, the superiority of this procedure over standard ACL reconstruction can't be judged. We do not know if the preserved ACL remnant was actually damaged at initial trauma. The decision of surgery is based on probing ACL remnants which is a subjective technique which may affect the results. The intact fibers of ACL on probing may not correlate to their functionality; thus a dysfunctional bundle may be preserved and affect the result. We did not evaluate proprioception with this augmentation procedure to document improvement with selective reconstruction.
Among 30 cases in our study, two patients had superficial wound infection at graft site, one patient has touniqet neuropaxia, three patient had neuropraxia of saphenous nerve and its infrapatellar branch and one patient has hemoarthrosis The complication rate in our study is 26.67%. All cases showed complete recovery on postoperative rehabilitation programs and conservative therapy.
Several authors have described complications Abat (12) , observe complication in three patients (10.7%). Two out of 18 of the AMB reconstructions (11.1%) had a persistent extension deficit. The postoperative radiographs confirmed that the tibial as well as the femoral tunnels were properly placed. The extension loss was attributed to Cyclops-like lesions in both patients .They were successfully treated with arthroscopic resection.. The remaining patient, with a PLB reconstruction , developed septic arthritis. The patient was treated with arthroscopic debridement and specific antibiotic therapy for 6 weeks.
Sabat D (13) , observe complication in five patient two patients had persisant extension deficit , one patient infection at graft site and two patient had neuropraxia of sapenous and its infrapatellar branch 1010

Conclusion:-
Our study confirms that selective bundle ACL reconstruction with preservation of the remnant bundle restores knee stability and function. The clinical outcomes were statistically improved and similar to those already published for the selective bundle augmentation. Success after ACL reconstruction may depend not only on the tightness or strength of the reconstruction but also on the preservation of the intact fibers. Anatomic selective bundle augmentation is technically demanding , but reproducible. The results are encouraging with excellent side to side laxity. We therefore recommend saving the intact bundle of ACL while augmenting the torn bundle in selective cases.