Is quadruple semitendinosus tendon strands autograft a better choice than hamstring autograft for anterior cruciate ligament reconstruction? A comparative study with a mean follow-up of 3 years.

PURPOSE: The purpose of this study was to compare the clinical outcomes of ST4 with those of STGs with a minimum follow-up of 3 years. The hypothesis was that functional outcomes of the ST4 technique are at least as good as those of the STG technique. STUDY DESIGN: Cohort study. Level of evidence, 3 METHODS: Eighty-seven consecutive patients underwent isolated ACL reconstruction, 50 with the ST4 and 37 with STG. At the femoral side for both groups, the system of the fixation of the graft used a cortical fixation support and at the tibial side the group STG used an interference screw and the ST4 group used a tape locked system fixed by an interference screw. Clinical results were compared: IKDC score, KT-1000 arthrometry, radiologic evaluation of the differential laxity, as well as the Tegner score and the KOOS score. RESULTS: Two patients had a rerupture (STG), one in the ST4 group. The analysis of the subjective clinical results showed no statistically significant difference between the 2 groups. Differential laximetry was 0.7 mm ± 0.4 (0 to 2 mm) for the ST4 group and 1.6 ± 0.5 mm (0 to 3 mm) for the STG group with a statistically significant difference in favor of the ST4 group (p < 0.05). Age, sex, and presence of meniscal lesions were the factors influencing the KOOS score. CONCLUSION: This study comparing the clinical and laximetric results at the minimum 3-year follow-up of 2 ACL reconstruction techniques (ST4 vs STG) confirms the working hypothesis with an overall better score for the ST4 group.

Computer-assisted navigation in ACL reconstruction is attractive but not yet cost efficient.

PURPOSE: Conventional reconstruction of the anterior cruciate ligament (ACL) has a high success rate. Computer-assisted navigation systems (CANSs) have been developed to further improve the accuracy of tunnel positioning. What is the economic impact from the hospital perspective? METHODS: Patients having a first ACL reconstruction procedure were included in a prospective multicentre open controlled study comparing two groups: CANS versus conventional surgery. The primary clinical efficacy criterion was the objective International Knee Documentation Committee score at 1-2-year follow-up. Costs were collected retrospectively nationwide. RESULTS: No significant differences were found for the clinical effectiveness between conventional surgery (100 patients) and CANS (114 patients) at follow-up: ORadjusted 1.01 [0.36-2.84] (n.s). Junior surgeons achieved a significant mean decrease in operating time during the study period: 30 % in the CANS group compared with 10 % in the control group (p < 0.01). The average cost of surgery was 704 for the control group and 1,158 for the CANS group (p < 0.01). The cost of the operating room accounts for >70 % of the total cost. The surgeon's status and the technical CANS learning effect influenced this cost. The cost differential between the two groups decreased with 'CANS' expertise: 238 and 271 in 'expert' centres versus 427 to 731 in other centres. CONCLUSION: While our study demonstrates the feasibility and the potential interest of CANS for training in ACL reconstruction, from a hospital perspective it is not cost efficient at present. LEVEL OF EVIDENCE: Economic and decision analysis-developing an economic or decision model, Level II.

Computer navigation for revision of unicompartmental knee replacements to total knee replacements: the results of a case-control study of forty six knees comparing computer navigated and conventional surgery.

PURPOSE: The revision of unicompartmental knee replacements (UKRs) to total knee replacements (TKRs) using computer navigation is a little-known technique. The principal objective of this study was to analyse the radiological position of implants in revision of UKR to TKR comparing the results of surgery aided by computer navigation (CAS) with conventional surgery (CS). Our hypothesis was that computer navigation would improve the position of the implants. METHODS: This is a retrospective single surgeon series. Forty-six patients (46 knees) with an average age 73 ± eight years (53-93) between January 1995 and December 2014 were included. The two groups were made up of 23 patients each and are comparable in terms of age, sex, side of surgery, age of the UKR, cause of failure and HKA angle before surgery. All patients were reviewed by two independent observers. RESULTS: In the CAS group, the average hip-knee-ankle (HKA) angle was 179.2 ± 2.2° (175-184°). The average medial tibial mechanical angle (TMA) was 88.4 ± 1.6° (84-90°) and the medial femoral mechanical angle (FMA) was 91 ± 2° (87- 94°). The tibial slope was 88.7 ± 1.1° (87-90°). In the CS group, the average HKA angle was 179.9 ± 1.9° (175-183°), the TMA was on average 89.1 ± 1.3° (87-93°) and the FMA was 90.6 ± 1.5° (87-93°). The tibial slope was 87.8 ± 4.9° (85-95°). There was no statistically significant difference between the two groups on any of the radiological parameters studied. CONCLUSIONS: Our radiological target of a post-operative HKA angle of 180 ± 3° was obtained in 87.5% of cases in the CS group and 92.4% of cases in the CAS group. This slight difference in favour of the computer-assisted group was not statistically significant, and we cannot therefore confirm our initial hypothesis, at least in the hands of an experienced surgeon. However, the quality of the results in the CAS group suggest that this technique could provide precious assistance to less experienced surgeons performing this surgery.

Good surgical outcome of transphyseal ACL reconstruction in skeletally immature patients using four-strand hamstring graft.

PURPOSE: Our purpose was to evaluate the clinical and radiological outcome at maturity of an « adult-like ¼ transphyseal anterior cruciate ligament (ACL) reconstruction performed in skeletally immature patients using four-strand hamstring graft. METHODS: The records of all skeletally immature patients who underwent transphyseal ACL reconstruction between 2004 and 2006 at our institution were reviewed. Inclusion criteria were age less than 16 years and radiographic evidence of open physes. Thirty-eight children and prepubescents were identified. All underwent postoperative clinical evaluation with International Knee Documentation Committee scores and long leg radiographs. Each patient was followed up until skeletal maturity was confirmed. RESULTS: Twenty-eight patients were scored A, four B, and five D according to IKDC. At last follow-up, there was no radiographic evidence of malalignment in any of the patients. Five underwent a reoperation. Three patients suffered traumatic graft disruption and two from post-operative knee instability. CONCLUSION: Early operative treatment by means of the quadruple hamstring free graft appears to be a safe and relevant procedure for ACL reconstruction even in skeletally immature patients.

Intraoperative comparisons of knee kinematics of double-bundle versus single-bundle anterior cruciate ligament reconstruction.

PURPOSE: Based on biomechanical anatomical studies, double-bundle reconstruction of the anterior cruciate ligament (ACL) was introduced to achieve better stability in the knee, particularly in respect of rotatory loads. An in vivo, computer-assisted, double-bundle (DB) ACL reconstruction is superior to a single-bundle (SB) ACL reconstruction at reducing rotatory, and AP laxities of the tibia at 20 degrees of knee flexion and also during the pivot shift test. METHODS: The data of 63 patients who had ACL reconstruction were prospectively collected. Thirty-two patients had single-bundle reconstruction (SB group), and 31 received double-bundle reconstruction (DB group). The per-operative navigation system (Praxim ACL surgetics System) helped to search for a minimal anisometry profile of the grafts, which was favorable (graft loosened with flexion) in the anatomic area of ACL insertion and preventing any conflict between the graft and the femoral notch. The system also evaluated anteroposterior (AP) rotational stabilities and pivot shift. The value of the pivot shift was calculated from the values of the maximum rotation and AP translation obtained when performing the manoeuver before and after ACL reconstruction, comparing SB and DB reconstruction. RESULTS: The post-operative AP displacement of the lateral compartment during the Lachman test was statistically reduced in DB group in comparison with SB group (5.1 ± 4.4 mm vs. 7.1 ± 3.2 mm, P = 0.04), whereas the AP displacements of the medial compartment were also reduced (3.4 ± 3.7 mm vs. 4.5 ± 2.6 mm, P = 0.15) but with no statistical significance. Internal and external rotations at 20° of knee flexion were lower in the DB group than in SB group with statistical significance (respectively, 13.2 ± 4.9° vs. 17.5 ± 4.0°, P < 0.001 and 9.1 ± 3.6° vs. 11.5 ± 3.5°, P = 0.01). During the pivot shift test, the post-operative AP maximal translation was statistically different in both groups: 4.5 ± 2.1 mm in DB group and 6.3 ± 2.7 mm in SB group (P = 0.01)), whereas the maximal rotation was not statistically different: 3.8 ± 2.5° in DB group and 3.4 ± 1.2° in SB group (n.s.). Therefore, Colombet's index was similar in DB group and SB group (respectively, 0.21 ± 0.16 and 0.17 ± 0.06, (n.s.)). CONCLUSIONS: This study shows a significant intraoperative advantage in anterior and rotational stability for four-tunnel DB ACL reconstruction compared with SB ACL reconstruction. LEVEL OF EVIDENCE: II.

Anterior cruciate ligament reconstruction with the Tape Locking Screw (TLS) and a short hamstring graft: Clinical evaluation of 61 cases with a minimum 12 months' follow-up.

INTRODUCTION: The Tape Locking Screw (TLS®) technique for anterior cruciate ligament (ACL) reconstruction has the advantages of using only one hamstring tendon (semitendinosus) by preparing a short graft secured with screws and braided strips. The theoretical pitfall of this technique is that the graft length is determined arbitrarily. Thus, if the blind tunnels are not long enough, it will be impossible to tension the graft properly upon fixation. The primary objective of this study was to determine the postoperative side-to-side difference in knee laxity. We hypothesized that ACL reconstruction with the TLS(R) system would result in 3mm or less side-to-side difference in knee laxity. MATERIAL AND METHODS: This was a prospective single-center, single-surgeon study performed on patients operated between December 2014 and June 2016 who had a minimum 12 months' follow-up. The pre- and post-operative side-to-side difference in knee laxity was measured with a KT-1000 arthrometer. Secondary outcomes were the pre- and post-operative IKDC, Lysholm and Tegner functional scores. RESULTS: Sixty-one patients were included: 49 men (80%) and 12 women (20%). The average age was 31.6±13.7 years. The average follow-up was 19.3±6.3 months. The average side-to-side difference in laxity went from 6.5mm (min 3; max 12) preoperatively to -0.1mm postoperatively (min -5, max 4) (p<0.01). The average IKDC went from 39.7±12 preoperatively to 94.1±11.2 postoperatively (p<0.005), the average Lysholm score went from 41±12.9 to 95.5±9.8 (p<0.005), and the average Tegner score went from 6.3±1.5 to 4.3±1.4 (p<0.005). Patients were able to return to sports an average of 6.1 months after surgery. In terms of complications, 4.9% of patients developed a cyclops lesion and required surgical revision. DISCUSSION: This study found very good reduction in postoperative laxity after a minimum 12 months' follow-up when ACL reconstruction is performed with the TLS® technique. LEVEL OF EVIDENCE: IV, prospective cohort study.

Reconstruction of the Posterolateral Corner After Sequential Sectioning Restores Knee Kinematics.

BACKGROUND: Various surgical techniques to treat posterolateral knee instability have been described. To date, the recommended treatment is an anatomic form of reconstruction in which the 3 key structures of the posterolateral corner (PLC) are addressed: the popliteofibular ligament, the popliteus tendon, and the lateral collateral ligament. PURPOSE/HYPOTHESIS: The purpose of this study was to identify the role of each key structure of the PLC in kinematics of the knee and to biomechanically analyze a single-graft, fibular-based reconstruction that replicates the femoral insertions of the lateral collateral ligament and popliteus to repair the PLC. The hypothesis was that knee kinematics can be reasonably restored using a single graft with a 2-strand "modified Larson" technique. STUDY DESIGN: Descriptive laboratory study. METHODS: Eight fresh-frozen cadaveric knees were used in this study. We conducted sequential sectioning of the popliteofibular ligament (PFL) and then subsequently the popliteal tendon (PT), the lateral collateral ligament (LCL), and the anterior cruciate ligament (ACL). We then reconstructed the ACL first and then the posterolateral corner using the modified Larson technique. A surgical navigation system was used to measure varus laxity and external rotation at 0°, 30°, 60°, and 90° with a 9.8-N·m varus stress and 5-N·m external rotation force applied to the tibia. RESULTS: In extension, varus laxity increased only after the sectioning of the lateral collateral ligament. At 30° of flexion, external rotation in varus and translation of the lateral tibial plateau increased after the isolated popliteofibular ligament section. From 60° to 90° of flexion, translation and mobility of the lateral plateau section increased after sectioning of the PFL. After reconstruction, we observed a restoration of external varus rotation in extension and translation of the lateral tibial plateau at 90° of flexion. This technique provided kinematics similar to the normal knee. CONCLUSION: The PFL has a key role between 30° and 90° of flexion, and the lateral collateral ligament plays a role in extension. Reconstruction with the modified Larson technique restores these 2 complementary stabilizers of the knee. CLINICAL RELEVANCE: Although there are many different techniques to reconstruct the PLC-deficient knee, this study indicates that a single-graft, fibular-based reconstruction of the LCL and PT may restore varus and external rotation laxity to the knee.

[Computer assisted systems for arthroscopic reconstruction of anterior cruciate].

OBJECTIVE: To introduce several navigation systems in anterior cruciate ligament reconstruction and to investigate the application of navigation systems for the improvement in reconstruction of the anterior cruciate ligament. METHODS: The related literature was reviewed extensively, and the main current computer assisted surgery systems (OthoPilot system, Bone Morphing system, Fluoroscopic-based system, etc) for utilization in the anterior cruciate ligament reconstruction were analyzed. RESULTS: The computer-assisted systems can enhance the accurate placement of tunnels. According to the anatomical and isometric parameters, graft impingement on the intercondylar notch could be avoided, and individual ideal implantation using 3D visualization localisers was achieved. CONCLUSION: It is possible that computer-assisted systems will enable surgeons to better acquire the accuracy and reliability of the various operative techniques, to meet the demand of surgeon's surgical optimisation and to improve the clinical results.