Predictive value of preoperative 3-dimensional computer tomography measurement of semitendinosus tendon harvested for anterior cruciate ligament reconstruction.

PURPOSE: The aim of this study was to evaluate preoperative measurement of the semitendinosus tendon (ST) by 3-dimensional computed tomography (3-D CT), before using ST as the substitute in the anterior cruciate ligament (ACL) reconstruction. TYPE OF STUDY: Cross-sectional study to compare anatomic findings with clinical findings. METHODS: The study involved 28 patients who underwent ACL reconstruction using autogenous ST graft. Preoperative 3-D CT images of ST were obtained with a multidetector-row CT scanner, and rendered qualitatively by the volume-rendering technique. The length and cross-sectional area of ST measured with 3-D CT were compared with the length of the harvested ST and the cross-sectional area of the grafted quadrupled tendon. RESULTS: The total length of ST measured with 3-D CT ranged from 220.3 to 285.4 mm, with a mean (+/- SD) of 248.0 +/- 17.1 mm, and that measured at surgery ranged from 230.0 to 290.0 mm, with a mean of 257.1 +/- 16.5 mm. These 2 values showed a close positive correlation (gamma = 0.634, P = .002). The cross-sectional area of ST measured with 3-D CT ranged from 4.29 to 18.5 mm2 with a mean of 11.9 +/- 4.6 mm2, and that of the substitute measured at surgery ranged from 28.3 to 56.7 mm2 with a mean of 45.5 +/- 6.9 mm2). There was no significant correlation between the areas of ST measured by CT and the areas of ST measured during surgery. CONCLUSIONS: Preoperative 3-D CT imaging predicts the length of ST. These findings support the measurement of ST length by 3-D CT as a useful tool for planning ACL reconstructive surgery and for providing important preoperative information to patients. LEVEL OF EVIDENCE: Level III, diagnostic study.

A long-term follow-up study after medial patellofemoral ligament reconstruction using the transferred semitendinosus tendon for patellar dislocation.

The management of patellar dislocation syndrome has traditionally been difficult. There are no golden standard methods for patellar dislocations probably due to the many etiologies. However, it is known that medial patellofemoral ligament (MPFL) is damaged when the patella is dislocated. The purpose of this study is to examine whether our method of MPFL reconstruction is useful for the treatment of dislocated patellae and unstable patellae. Forty-six knees (43 patients) of 68 knees (65 patients) that were operated on using our surgical procedure for MPFL reconstruction with the advancement of the vastus medialis or the MPFL reconstruction with Insall's procedure were followed up for at least 5 years. The patient age ranged from 6 to 43 years. These knees consisted of six habitual dislocation patellae, twenty-six recurrent dislocation patellae, ten traumatic dislocation patellae, and four unstable patellae. The patients were evaluated pre-operatively and more than three times post-operatively at 6, 12, 36, 60, or 120 months. No patient experienced patellar dislocation after surgery. Their post-operative Kujala's scores were significantly improved. On conventional X-ray and on stress X-ray evaluations, the mean values for congruence angle, tilting angle, lateral shift ratio, medial stress shift ratio, and lateral stress shift ratio at the final follow-up (60 or 120 months) were demonstrated to be within the normal range. We conclude that our MPFL reconstruction method with the advancement of the vastus medialis or with Insall's procedure might be recommended for the treatment of habitual, recurrent, and indeed any other type of patellar dislocation, as well as for unstable patellae.

Three-dimensional computed tomography imaging evidence of regeneration of the semitendinosus tendon harvested for anterior cruciate ligament reconstruction: a comparison with hamstring muscle strength.

OBJECTIVE: The purpose of this study was to evaluate the regeneration of semitendinosus tendons harvested for anterior cruciate ligament (ACL) reconstruction using 3-dimensional (3D) computed tomography (CT) imaging and to compare the degree of regeneration with hamstring strength. METHODS: Twenty-nine patients who underwent ACL reconstruction using ipsilateral autogenous semitendinosus tendons were examined before surgery and 6 and 12 months after surgery by 3D CT imaging. The types of regenerated tendons and the proximal shift of the muscle-tendon junction were evaluated. RESULTS: The types of regenerated semitendinosus tendons varied from case to case. There was a positive correlation between the peak torque ratio of the hamstring muscle strength and the proximal shift of the muscle-tendon junction 6 months after surgery. The proximal shift did not affect the peak torque ratio 12 months after surgery, however. CONCLUSIONS: A proximal shift of the muscle-tendon junction may help to explain the individual differences in early postoperative hamstring muscle strength recovery.

Anterior cruciate ligament graft impingement against the posterior cruciate ligament: diagnosis using MRI plus three-dimensional reconstruction software.

OBJECTIVE: The purpose of this study was to evaluate anterior cruciate ligament (ACL) impingement against the posterior cruciate ligament (PCL) with the knee in an extended position, which arthroscopy cannot detect. MATERIALS AND METHODS: Ten normal knees and 30 ACL-reconstructed knees were assessed using MR imaging. The three-dimensional reconstruction of the ACL, PCL, femur and tibia were carried out using commercially available three-dimensional reconstruction software. Anterior cruciate ligament impingement against the PCL was graded into three categories: Grade 1, some space between the ligaments; Grade 2, no space between the ligaments, and the reconstructed ACL ran straight; and Grade 3, the reconstructed ACL did not run straight. The angle of the reconstructed ACL against the tibial plateau was also measured. RESULTS: All normal knees were classified as Grade 1. The 30 reconstructed knees were classified as follows: Grade 1, 12 cases; Grade 2, 7 cases; and Grade 3, 11 cases. The mean angle of the Grade 3 reconstructed ACL knees was significantly more vertical against the tibia as compared with the Grade 1 knees (P<.05). The postoperative KT-2000 side-to-side difference of the Grade 3 knees (2.8+/-4.5 mm) was larger than that of the Grade 1 knees (0.2+/-1.7 mm) and Grade 2 knees (-0.6+/-2.2 mm), but no statistically significant difference could be detected between the three groups in the postoperative KT-2000 data. CONCLUSION: This method is useful to evaluate ACL impingement against PCL, which cannot be detected by conventional arthroscopy during the operation. The surgeon should pay careful attention to the coronal angle of the reconstructed ACL.

Synovial cyst formation resulting from nonabsorbable meniscal repair devices for meniscal repair.

Several arthroscopic meniscal repair techniques and devices have been developed during the past decade. The Mitek Meniscal Repair System (Mitek, Ethicon, Norderstedt, Germany) is one of these devices. We report a case of synovial cyst formation after medial meniscus repair with a nonabsorbable Mitek Meniscal Repair System. The cyst in the right knee developed 5 months after the meniscus repair. After excision of the synovial cysts and removal of these devices, the mass and pain of the knee were relieved. To our knowledge, this is the first report of synovial cyst formation resulting from this device.