Anterior cruciate ligament reconstruction graft harvesting: pitfalls and tips

Preoperative Estimated Width of the Patellar Tendon for Anterior Cruciate Ligament Reconstruction

This study aims to compare the actual patellar tendon width with the skin and magnetic resonance imaging (MRI) measurements and to describe a more accurate method to predict the actual patellar tendon width before anterior cruciate ligament reconstruction (ACLR).Thirty-nine patients undergoing primary ACLR were identified. Patients with patellar tendon width of less than 30 mm by skin or MRI measurements were excluded from the study. The actual patellar tendon width was measured as an intraoperative reading taken after surgical exposure. Mean difference between the skin and actual measurement and mean difference between the MRI and actual measurement was calculated. Paired t-test was run to determine any significant differences. A difference was also calculated between the actual measurement and the average sum of skin and MRI measurements for each patient. Skin thickness was compared to Δ (Δ = preincision skin measurement of patellar tendon width minus postincision actual measurement) by Spearman's correlation test. Mean difference between skin and actual measurements was 2.5 mm, with p = 0.001. Mean difference between MRI and actual measurement was -2.7 mm with p = 0.001. However, the mean difference between the actual and the average sum of skin and MRI measurements was 0.13 mm with p = 0.76. The Pearson's correlation coefficient, r _s, between average sum of skin and MRI measurements and the actual measurement was 0.6 with p = 0.001. There was no correlation found between the skin thickness and Δ∙. This study indicates that there is a significant difference between the actual patellar tendon width and the measurement of the tendon taken using a ruler on the skin or using MRI image software. However, the average sum of skin and MRI measurements, which is not significantly different from the actual width, can accurately predict the actual patellar tendon width before ACLR. The study reflects level IV evidence.

A proposal for a new classification of pes anserinus morphology

PURPOSE

The pes anserinus (PA) is characterized by high morphological diversity. As the semitendinosus and gracilis muscle tendons are routinely harvested for the reconstruction of other tendons, especially the anterior cruciate ligament (ACL), it is of clinical importance. The presence of accessory bands within PA tendons can handicap the harvesting process. Therefore, the purpose of the study was to suggest a new morphological classification of the PA morphology.

METHODS

Classical anatomical dissection was performed on 102 lower limbs (56 right, 46 left) fixed in 10% formalin solution. The morphology and insertion of the PA (including accessory bands) were assessed, and morphometric measurements were taken.

RESULTS

In all cases, the PA was present and composed of the sartorius, gracilis and semitendinosus tendons. Six types of PA were distinguished based on the presence of accessory bands. The most common composed of monotendinous sartorius, gracilis and semitendinosus-54 limbs (52.9%). Additionally, three types of insertion were noted (short, band-shaped and fan-shaped). The mean length between the insertion and the origin of the accessory bands to the fascia of the gastrocnemius muscle was 63.5 mm.

CONCLUSION

The morphology of the PA was highly variable. The gracilis and semitendinosus tendons often had accessory bands that would complicate the harvesting process. The planning of surgical procedures may be improved by our proposed classification.

Use of Posterior Hamstring Harvest During Anterior Cruciate Ligament Reconstruction in the Pediatric and Adolescent Population

Background:

Posterior hamstring harvest has been described in the adult population in a limited fashion, but no study is available describing the use of posterior hamstring harvest in an active pediatric and adolescent cohort. At times, surgeons may be faced with a challenging anterior harvest due to patient anatomic characteristics, particularly the anatomic features and size of the pes tendons. Clinicians need to have multiple harvest approaches at their disposal. Complications with hamstring harvest such as premature graft transection are more problematic in this population due to higher failure rates with allograft tissue. The posterior harvest via its more proximal location may allow for easier tendon identification, visualization of the accessory attachments, and longer preserved tendon length if transection error occurs when the anterior approach is avoided based on surgical technique, patient anatomic characteristics, and surgeon and patient preference.

Purpose:

To describe the technique of a posterior hamstring harvest in pediatric and adolescent patients and to analyze complications.

Study Design:

Case series; Level of evidence, 4.

Methods:

This study was a retrospective review of a consecutive series of pediatric and adolescent patients who underwent posterior hamstring harvest. During surgery, the patient’s leg was abducted and externally rotated to expose the posteromedial aspect of the knee. A 2-cm incision was made overlying the palpable medial hamstring at the popliteal crease. The posterior hamstring tendons were first harvested proximally with an open tendon stripper and distally with a closed stripper. Preoperative, intraoperative, and postoperative findings and complications were analyzed.

Results:

A total of 214 patients (mean ± SD age, 15.7 ± 4.1 years; range, 8.0-19.8 years) underwent posterior harvest, with a mean ± SD follow-up of 1.83 ± 1.05 years. No complications occurred in our series related to graft harvest—no graft transections, neurovascular injuries, secondary procedures for wound healing or closure, cosmetic concerns, or limitations in return to activity due to the posterior incision.

Conclusion:

The posterior hamstring harvest is a safe and reliable technique to harvest autograft tendon in pediatric and adolescent anterior cruciate ligament reconstructions. The posterior technique entailed no complications related to harvest. No patients expressed any cosmetic concerns about their incision or had limitations in return to sport due to the posterior harvest.

Accessory bands of the hamstring tendons: A clinical anatomical study

Gracilis and semitendinosus tendons are commonly used as grafts in ligamentous reconstruction. Awareness of accessory bands of these tendons is essential in preventing inadvertent diversion of the tendon harvester into the main tendon resulting in premature tendon amputation and inadequate tendon graft. The aim of this study was to describe the characteristics of these accessory bands. Twenty five patients undergoing arthroscopic anterior cruciate ligament reconstruction using hamstring tendons were included. The number of accessory bands and distance of the most proximal band from the distal periosteal insertion point on the tibial crest was recorded for both gracilis and semitendinosus. In most cases gracilis had two accessory bands; the average distance of the most proximal band from the tibial crest insertion being 5.1 cm. Semitendinosus had three bands in most cases, the average distance of the most proximal band from the tibial crest insertion being 8.1 cm. Five (20%) semitendinosus but no gracilis tendons had an accessory band originating greater than 10 cm from the tibial crest insertion. Semitendinosus had more accessory bands compared to gracilis. A significant proportion (20%) of semitendinosus and none of the gracilis tendons had bands originating greater than 10 cm proximal to the tibial crest insertion. This knowledge about the accessory bands of the hamstrings can guide toward safe harvesting of these tendons.

Magnetic resonance imaging of double-bundle anterior cruciate ligament reconstruction

Reconstruction of the anterior cruciate ligament (ACL) using the double-bundle technique is getting highly increasing attention. This surgical approach uses two separate tendon grafts with the intention to reconstruct both anatomic bundles in order to restore the full biomechanical function of the original ligament. With the increasing popularity of this technique, radiologists will be more frequently confronted with patients who underwent this surgical procedure. The aims of this essay are to briefly describe the basic biomechanical and surgical principles and to summarize the magnetic resonance imaging findings of the knee after double-bundle ACL reconstruction.