Posterior horn medial meniscal root tear: the prequel.

OBJECTIVE: To determine whether subarticular marrow changes deep to the posterior horn medial meniscal root anchor might predict subsequent medial meniscal root tear. MATERIALS AND METHODS: Fifteen patients with MR-diagnosed posterior horn medial meniscal root (PHMMR) tear and a knee MRI antecedent to the tear were identified at three imaging centers over a 7-year period. The pre- and post-tear MR images were evaluated for marrow signal changes deep to the root anchor, meniscal root signal intensity, medial compartment articular cartilage thinning, and meniscal body extrusion. Images of 29 age- and gender-matched individuals with two MRIs of the same knee were reviewed as a control group. RESULTS: MRI in 11 of 15 (73%) cases with subsequent PHMMR tear demonstrated linear subcortical marrow edema deep to the meniscal root anchor on the antecedent MRI compared to only 1 of 29 (3%) non-tear controls (p < 0.0001). The abnormal signal resolved on post-tear MRI in all but two patients. Cyst-like changes deep to the PHMMR were present on initial MRI in three of 15 (23%) cases and three of 29 (10%) controls, persisting in all but one case on follow-up imaging. The PHMMR was gray on the initial MRI in seven of 15 (47%) of cases that developed tears compared to four of 29 (14%) controls (p < 0.0001). There was medial meniscal extrusion (MME) prior to tear in two of 15 (13%) patients and in ten of 15 (67%) patients after PHMMR failure. In the control group, MME was present in one (3%) and three (10%) of 29 subjects on the initial and follow-up MRIs, respectively. Articular cartilage loss was noted in two of 15 (15%) cases before tear and nine of 15 (69%) on follow-up imaging, as compared to one (3%) and four (14%) of 29 subjects in the control group. CONCLUSIONS: Subcortical marrow edema deep to the PHMMR may result from abnormal stresses and thus be a harbinger of meniscal root failure. This hypothesis is supported by resolution of these marrow signal changes after root tear. Following tear, extrusion of the meniscal body results in increased stress on the medial weight-bearing surfaces often leading to articular cartilage loss; we observed this sequence in six of our 15 patients with PHMMR tears.

Bucket handle tears of the medial meniscus: meniscal intrusion rather than meniscal extrusion.

OBJECTIVE: To determine the frequency of medial meniscal extrusion (MME) versus "medial meniscal intrusion" in the setting of bucket handle tears. Images were evaluated for previously reported risk factors for MME, including: medial meniscal root tear, radial tear, degenerative joint disease and joint effusion. METHODS: Forty-one consecutive cases of bucket handle tear of the medial meniscus were reviewed by consensus by two musculoskeletal radiologists. Imaging was performed using a 1.5 GE Signa MR unit. Patient age, gender, medial meniscal root integrity, MME, medial meniscal intrusion, degenerative joint disease, effusion and anterior cruciate ligament (ACL) tear were recorded. RESULTS: Thirteen females and 27 males (age 12-62 years, median=30 years) were affected; one had bucket handle tear of each knee. Effusion was small in 13, moderate in 9 and large in 18. Degenerative joint disease was mild in three, moderate in two and severe in one. 26 ACL tears included three partial and three chronic. Medial meniscal root tear was complete in one case and partial thickness in two. None of the 40 cases with an intact or partially torn medial meniscal root demonstrated MME. MME of 3.1 mm was seen in the only full-thickness medial meniscal root tear, along with chronic ACL tear, moderate degenerative joint disease and large effusion. Medial meniscal intrusion of the central bucket handle fragment into the intercondylar notch was present in all 41 cases. CONCLUSION: Given an intact medial meniscal root in the setting of a "pure" bucket handle tear, there is no MME.

The accessory posterior portal for shoulder arthroscopy: Description of technique and cadaveric study.

As the indications for shoulder arthroscopy continue to expand, so too does the need for complete access to the glenohumeral joint. Specific regions of the joint, including the axillary recess, are often times difficult to access using traditionally described posterior and anterior portals. In this article, we describe a technique for the placement of an accessory posterior portal into the inferior hemisphere of the glenohumeral joint, effectively in the 8 o'clock or 4 o'clock position. To demonstrate the safety and effectiveness of this portal, 6 cadaveric specimens were dissected after the placement of a standard and accessory posterior portal. The proximity of the posterior portals to the axillary and suprascapular nerves was analyzed. Measurements were made in simulated beach-chair and lateral decubitus positions. The authors show that the accessory posterior portal is safe to use and may prove useful to the surgeon who wishes to gain access to the inferior recesses of the glenohumeral joint.

Cardiac arrest as a result of intraabdominal extravasation of fluid during arthroscopic removal of a loose body from the hip joint of a patient with an acetabular fracture.

The case of a fifty-year-old man who suffered an isolated, associated, both-column fracture of the left acetabulum is presented. He underwent an uncomplicated open reduction and internal fixation through an ilioinguinal approach. A follow-up computed tomographic scan was performed postoperatively, which documented intraarticular fragments. Hip arthroscopy was performed to remove the fragments. During the procedure, arthroscopic fluid extravasated through the fracture site under pump pressure and resulted in an intraabdominal compartment syndrome that presented as cardiopulmonary arrest. An emergent exploratory laparotomy was performed to release the fluid and resume blood flow. Despite prolonged asystole, the patient survived without neurologic sequelae. The literature on compartment syndrome secondary to arthroscopic procedures is reviewed. Because of this previously unreported potentially lethal complication, we do not advocate hip arthroscopic procedures for acute or healing acetabular fractures.