Biological and Biomechanical Evaluation of Autologous Tendon Combined with Ligament Advanced Reinforcement System Artificial Ligament in a Rabbit Model of Anterior Cruciate Ligament Reconstruction.

OBJECTIVE: To compare the biomechanical and histological changes in a rabbit model after reconstructing the anterior cruciate ligament (ACL) with solely autologous tendon and with autologous tendon combined with the ligament advanced reinforcement system (LARS) artificial ligament. METHODS: Anterior cruciate ligament reconstruction was performed in 72 knees from 36 healthy New Zealand white rabbits (bodyweight, 2500-3000 g). The Achilles tendons were harvested bilaterally. The left ACL were reconstructed solely with autografts (autologous tendon group), while the right ACL were reconstructed with autografts combined with LARS ligaments (combined ligaments group). The gross observation, histological determination, and the tension failure loads in both groups were evaluated at 12 weeks (n = 18) and 24 weeks (n = 18) postoperatively. RESULTS: Gross examination of the knee joints showed that all combined ligaments were obviously covered by a connective tissue layer at 12 weeks, and were completely covered at 24 weeks. Fibrous tissue ingrowth was observed between fascicles and individual fibers in the bone-artificial ligament interface at both time points; this fibrovascular tissue layer localized at the bone-artificial ligament interface tended to be denser in specimens obtained at 24 weeks compared with those obtained at 12 weeks. The tension failure loads of the knees were similar in the autologous tendon group and the combined ligaments group at 12 weeks (144.15 ± 3.92 N vs. 140.88 ± 2.75 N; P > 0.05), and at 24 weeks (184.15 ± 1.96 N vs. 180.88 ± 3.21 N; P > 0.05). CONCLUSION: Reconstructing the ACL in rabbits using autologous tendon combined with the LARS artificial ligament results in satisfactory biointegration, with no obvious immunological rejection between the autologous tendon and the artificial ligament, and is, therefore, a promising ACL reconstruction method.

Influence of different great trochanteric entry points on the outcome of intertrochanteric fractures: a retrospective cohort study.

BACKGROUND: The Proximal Femoral Nail Antirotation (PFNA) system for treatment of intertrochanteric fractures is currently widely applied worldwide. However, even though the PFNA has produced good clinical outcomes, a poor introduction technique with an inappropriate entry point can cause surgical complications. Some researchers suggest improving clinical outcomes by modifying the entry point, but no research has focused on this issue. The purpose of the present study is to compare the clinical and radiological outcomes of two different trochanteric entry points for the treatment of intertrochanteric fractures using the PFNA system. METHODS: From May 2010 to October 2015, a total of 212 elderly patients with intertrochanteric fractures who were treated with the PFNA-II system were included into this retrospective cohort study. Group LA (98 patients) was treated using a lateral anterior trochanteric entry point, and group MP (114 patients) was treated using a medial posterior trochanteric entry point. All patients underwent follow-up assessments at 1, 3, 6, and 12 months after surgery. Radiographic evaluation was based on the impingement, tip-apex distance (TAD) and the position of the helical blade within the femoral head. Clinical evaluation was based on the surgical time, fluoroscopy time, blood loss, hospital stay, visual analogue scale (VAS), thigh pain, and Harris hip score. RESULTS: The impingement was significantly reduced (P = 0.011) in group MP. The helical blade positions were significantly lower (P = 0.001) in group MP. The TADs in group LA (22.40 ± 4.43) and group MP (23.39 ± 3.60) were not significantly different (P = 0.075). The fluoroscopy time of group LA (53.26 ± 14.44) was shorter than that of group MP (63.29 ± 11.12, P = 0.000). Five iatrogenic lateral proximal fractures and 3 helical blade cutouts occurred in group LA, but none occurred in group MP. At 1 and 3 months postoperation, the Harris hip scores were significantly higher in group MP (P = 0.001 and P = 0.000, respectively), and the VAS scores were lower (P < 0.05). CONCLUSIONS: The medial posterior trochanteric entry point achieved excellent nail and helical blade position, reduced surgical complications, and enabled early hip function recovery but required longer fluoroscopy time than the lateral anterior trochanteric entry point.

Single-bundle modified patellar tendon versus double-bundle tibialis anterior allograft ACL reconstruction: a prospective randomized study.

PURPOSE: The purpose of this study was to prospectively compare the outcomes of single-bundle (SB) anterior cruciate ligament (ACL) reconstruction with modified bone-patellar tendon-bone (BPTB) allograft and double-bundle (DB) reconstruction with tibialis anterior allograft. METHODS: With 94 patients enroled in the study, 43 subjects who had SB ACL reconstruction with modified BPTB allograft (group S) and 41 subjects of DB ACL reconstruction with tibialis anterior allograft (group D) were followed up for a minimum of 2 years. Clinical outcomes including Lachman and pivot-shift tests, KT-1000 arthrometer measurements, and the International Knee Documentation Committee (IKDC) classification, Lysholm and Tegner activity scores were compared between the two groups at the last follow-up. RESULTS: The mean graft size of the group S, the anteromedial bundle and posterolateral bundle in group D were 9.9 ± 0.2, 7.5 ± 0.4 and 6.6 ± 0.4 mm, with statistically significant difference between the group S graft to either bundle of group D grafts (p < 0.001). At the last follow-up, there was no statistical difference between the two groups for the Lachman test, pivot-shift test and side-to-side difference. Substantial improvements in the subjective knee function scores were achieved in both groups, but without significant difference between the two groups. CONCLUSIONS: After a 2-year minimum follow-up, SB ACL reconstruction based on modified BPTB allograft achieved similar clinical outcomes to DB reconstruction with tibialis anterior allograft in knee stability, both anterior-posterior and rotational, as well as knee function. The modified BPTB allograft was recommended as an ideal graft option for the SB ACL reconstruction. LEVEL OF EVIDENCE: Therapeutic, randomized controlled study, Level II.

The horizontal Y-shaped graft with respective graft tension angles in anatomical two-bundle medial patellofemoral ligament reconstruction.

PURPOSE: Various techniques for medial patellofemoral ligament (MPFL) reconstruction have been described with two bundles of graft tensioned simultaneously. The present study was to introduce an anatomical reconstruction procedure using a horizontal Y-shaped graft with respective graft tension angles and report the preliminary results. METHODS: A surgical technique for MPFL reconstruction using a horizontal Y-shaped semitendinosus tendon autograft with two bundles tensioned at 0° and 30° of knee flexion was described in detail. The patellar stability was evaluated with the apprehension test and an axial computed tomography (CT) scan at 30° of knee flexion. The knee function was evaluated using the Lysholm and Kujala scores. RESULTS: No recurrent dislocation or subluxation was reported for 45 patients at a mean of 33.7-month follow-up. On CT images, congruence angle, patellar tilt angle, lateral patellar angle and lateral displacement were restored to the normal range. At the last follow-up, the mean Lysholm score improved from 51.8±6.2 to 91.7±4.1 and mean Kujala score was from 53.4±5.3 to 90.9±6.6 (P<0.01). CONCLUSIONS: The present anatomical MPFL reconstruction technique with a horizontal Y-shaped two-bundle graft tensioned at respective knee flexion angles could not only recreate the fan-shape of MPFL but also mimic the function bundles of native ligament. Clinical follow-up confirms the good restoration of the patellar stability and significant improvement of knee function without special complications. LEVEL OF EVIDENCE: Therapeutic, Level IV.

Non-surgical treatment for acute patellar dislocation with special emphasis on the MPFL injury patterns.

PURPOSE: The objective of present study was to propose a new classification for acute MPFL injury, which can help choose optimal treatment method for certain injury type. METHODS: Eighty-five patients with acute patellar dislocation treated non-surgically were retrospectively reviewed. They were assigned into two groups according to the newly introduced classification scheme, which classified MPFL injury into three types: injury in overlap region, injury in non-overlap region and combined injury of both regions. For study purpose, patients with combined injury were not included. Of 85 patients, 33 were in the overlap-region group (Group 1) and 52 in the non-overlap-region group (Group 2). Clinical patellar instability rate and patellofemoral score were measured and recorded at 2-year follow-up. RESULTS: The patellar instability rate was 15.2 % in Group 1 and 38.5 % in Group 2, with statistically significant difference between the two groups (P = 0.022). The mean visual analogue scale for Group 1 and Group 2 was 15.6 points and 28.3 points, respectively (P = 0.026). The mean Kujala score was 91.1 points and 82.6 points (P = 0.009), with a good or excellent subjective result recorded for 27 of 33 patients (81.8 %) in Group 1 compared with 30 of 52 patients (57.7 %) in Group 2 (P = 0.021). CONCLUSIONS: Non-surgical treatment achieves better clinical outcomes with respect to a lower patellar instability rate and better subjective function for the overlap-region injury of MPFL than for the non-overlap-region injury, and can be considered as treatment of choice for overlap-region injury of MPFL. The optimal choice for the non-overlap-region injury still requires further researches. LEVEL OF EVIDENCE: Therapeutic, Level IV.

Arthroscopic single-bundle ACL reconstruction with modified double-layer bone-patellar tendon-bone allograft.

PURPOSE: The objective of present study was to introduce a modified double-layer bone-patellar tendon-bone (BPTB) allograft for arthroscopic single-bundle ACL reconstruction and investigate the clinical outcomes. METHODS: From 2007 to 2009, a total of 136 patients underwent arthroscopic single-bundle ACL reconstructions with BPTB allograft. Of which, 66 patients were with double-layer BPTB allograft (Group 1), and 70 patients were with conventional BPTB allograft (Group 2). Clinical outcomes including Lachman and pivot-shift tests, KT-1000 arthrometer measurements, and Lysholm and Tegner activity scores were compared between the two groups at a 2-year minimum follow-up. RESULTS: Forty-six patients in each group were at a two-year minimum follow-up. The mean side-to-side difference on the KT-1000 arthrometer was 1.2 ± 1.2 mm for group 1 and 2.1 ± 1.9 mm for group 2, with significant difference between the two groups (p = 0.017). The knee function was significantly better for group 1 than for group 2, because the mean Lysholm score was 94.2 ± 4.8 points versus 86.6 ± 7.1 points (p = 0.000), and the median Tegner score was 8 (range 5-10) points versus 6 (range 4-10) points (p = 0.001). CONCLUSIONS: On the basis of the KT-1000 arthrometer evaluation and clinical measures, single-bundle ACL reconstruction with double-layer BPTB allograft achieves significantly lesser anterior laxity and better knee function than a single-layer allograft reconstruction. LEVEL OF EVIDENCE: Therapeutic, retrospective comparative study, Level III.

[Arthroscopic single-bundle anterior cruciate ligament reconstruction with six-strand hamstring tendon and patellar tendon allograft].

OBJECTIVE: To compare the outcome of arthroscopic single-bundle anterior cruciate ligament (ACL) reconstruction with six-strand hamstring tendon and patellar tendon allograft. METHODS: From October 2006 to December 2009, 108 patients with arthroscopic single-bundle ACL reconstruction were retrospectively reviewed, with 58 patients with six-strand hamstring tendon (Group H), and 50 patients with patellar tendon allograft (Group P). Patients were available for clinical evaluation with KT-1000 arthrometer measurements, Lachman and pivot-shift test, and knee function with the International Knee Documentation Committee (IKDC), Lysholm scores. RESULTS: All the patients were followed up at an average of 28.6 months (range 12 - 38 months). The average side-to-side difference was lesser for group H (1.2 ± 1.2) mm than group P (1.8 ± 1.5) mm (P < 0.05). On the pivot-shift test, 55 (94.8%) patients were negative and 3 (5.2%) were positive in group H, whereas 41 (82.0%) were negative and 9 (18.0%) were positive in group P, with significant difference between two groups (P < 0.05). All knee function scores were improved postoperatively, without statistically significant difference between the two groups (P > 0.05). CONCLUSION: Arthroscopic single-bundle ACL reconstruction with six-strand hamstring tendon will achieve better knee stability than patellar tendon allograft.

Combination of medial patellofemoral ligament reconstruction with vastus medialis advancement for chronic patellar dislocation.

BACKGROUND: The medial patellofemoral ligament (MPFL) reconstruction is popular in clinical practice for chronic patellar dislocation; however, the combination with vastus medialis advancement is rare. The aim of this study was to evaluate the clinical outcome of the combination of MPFL reconstruction with vastus medialis advancement. METHODS: We retrospectively analyzed 69 patients with chronic patellar dislocation between July 2004 and October 2008: twenty eight cases with isolated MPFL reconstruction (group I), forty one cases with the combination of MPFL reconstruction with vastus medialis advancement (group C). All patients had CT scans available for review with knee flexion at 30 degree, on which the congruence angle, patellar tilt angle and patellar lateral shift were measured. Physical apprehension tests were examined and the redislocation was recorded. In addition, knee function was evaluated using the Kujala score and subjective questionnaires. RESULTS: Patients were followed up for a mean of 42 months (12 - 65 months) without a recurrent dislocation reported. Postoperatively, all indexes on CT scan were within the normal range without a statistical difference between the two groups. Results from the apprehension test showed eight patients in group I and three in group C had patellar lateral shift exceeding 1.5 cm with a hard end point (P < 0.05). The Kujala score improved significantly from 51.3 ± 4.5 to 79.9 ± 6.2 in group I and from 53.7 ± 5.2 to 83.9 ± 6.5 in group C (P > 0.05). However, the subjective questionnaire revealed a significant difference (P < 0.05), including 12 excellent, seven good and nine fair in group I and 30 excellent, six good and five fair in group C. CONCLUSION: The combination of MPFL reconstruction with vastus medialis advancement is better than isolated reconstruction to improve the subjective effects and decrease the patellar instability rate for chronic patellar dislocation.

[Comparison of clinical results between an isometric and an anatomic technique for medial patellofemoral ligament reconstruction].

OBJECTIVE: To compare the clinical results of single-stranded isometric with double-stranded anatomic reconstruction of medial patellofemoral ligament (MPFL) for recurrent patellar dislocation. METHODS: Retrospective analysis of 60 consecutive patients (72 knees) with recurrent patellar dislocation underwent medial patellofemoral ligament reconstruction between August 2004 and October 2008, 22 cases (27 knees) with single-stranded isometric reconstruction, 38 cases (45 knees) with double-stranded anatomic reconstruction. Postoperatively patellar stability was examined, and recurrent rate was recorded. Patellar lateral shift ratio and tilt were measured on CT scans. Knee function was evaluated with subjective questionnaire and the Kujala score. RESULTS: All patients were followed up for more than 12 months without recurrent redislocation. (1) Recurrent instability rate was 18.5% in single-stranded group and 2.2% in double-stranded group, with statistical difference (P < 0.05). (2) The patellar tilt and lateral shift ratio returned to normal, without statistical difference between groups (P > 0.05). (3) The Kujala score were 59 ± 9 and 62 ± 9 preoperatively and 87 ± 4 and 94 ± 6 postoperatively in single- and double-stranded group, with statistical difference (P < 0.05). (4) The excellect rate was 85.2% in single-stranded group, 97.8% in double-stranded group, with statistical difference(P < 0.05). CONCLUSION: Both reconstruction can improve patellar stability and knee function significantly, with double-stranded anatomic reconstruction better in clinic evaluation.

Functional bundles of the medial patellofemoral ligament.

The purpose of this study was to explore the anatomy and evaluate the function of the medial patellofemoral ligament (MPFL). Anatomical dissection was performed on 12 fresh-frozen knee specimens. The MPFL is a condensation of capsular fibers, which originates at the medial femoral condyle. It runs transversely and inserts to the medial edge of the patella. With the landmark of the medial femur epicondyle (MFE), the femoral origination was located: just 8.90 ± 3.27 mm proximally and 13.47 ± 3.68 mm posteriorly to the MFE. The most interesting finding in present study was functional bundles of its patellar insertion. Approximately from the femoral origination point, fibers of the MPFL form two relatively concentrated fiber bundles: the inferior-straight bundle and the superior-oblique bundle. The whole length of each was 71.78 ± 5.51 and 73.67 ± 5.40 mm, respectively. The included angle between bundles was 15.1° ± 2.1°. Although the superior-oblique bundle and the inferior-straight bundle run on the patellar MPFL inferiorly and superiorly, respectively, as their name indicates, the two bundles are not entirely separated, which make MPFL one intact structure. The inferior-straight bundle is the main static soft tissue restraints where the superior-oblique bundle associated with vastus medialis obliquus (VMO) is to serve as the main dynamic soft tissue restraints. So this finding may provide the theoretical foundation for the anatomical reconstruction of the MPFL and shed lights on the future researchers.