Faculty Bibliography

Patellar tendinopathy (PT) is a clinical and chronic overuse condition of unknown pathogenesis and etiology marked by anterior knee pain typically manifested at the inferior pole of the patella. PT has been referred to as "jumper's knee" since it is particularly common among populations of jumping athletes, such as basketball and volleyball players. Due to its common refractory response to conservative treatment, a variety of new treatments have emerged recently that include dry-needling, sclerosing injections, platelet-rich plasma therapy, arthroscopic surgical procedures, surgical resection of the inferior patellar pole, extracorporeal shock wave treatment, and hyperthermia thermotherapy. Since PT has an unknown pathogenesis and etiology, PT treatment is more a result of physician experience than evidence-based science. This review will summarize the current literature on this topic, identify current research efforts aimed to understand the pathological changes in abnormal tendons, provide exposure to the emerging treatment techniques, and provide suggested direction for future research.

OBJECT: Our objective was to use 7 T MRI to compare cartilage morphology (thickness) and collagen composition (T2 values) in cartilage repair patients and healthy controls. MATERIALS AND METHODS: We scanned the knees of 11 cartilage repair patients and 11 controls on a 7 T MRI scanner using a high-resolution, gradient-echo sequence to measure cartilage thickness and a multi-echo spin-echo sequence to measure cartilage T2 values. We used two-tailed t tests to compare cartilage thickness and T2 values in: repair tissue (RT) versus adjacent cartilage (AC); RT versus healthy control cartilage (HC); AC versus HC. RESULTS: Mean thickness in RT, AC, HC were: 2.2 +/- 1.4, 3.6 +/- 1.1, 3.3 +/- 0.7 mm. Differences in thickness between RT-AC (p = 0.01) and RT-HC (p = 0.02) were significant, but not AC-HC (p = 0.45). Mean T2 values in RT, AC, HC were: 51.6 +/- 7.6, 40.0 +/- 4.7, 45.9 +/- 3.7 ms. Differences in T2 values between RT-AC (p = 0.0005), RT-HC (p = 0.04), and AC-HC (p = 0.004) were significant. CONCLUSION: 7 T MRI allows detection of differences in morphology and collagen architecture in: (1) cartilage repair tissue compared to adjacent cartilage and (2) cartilage repair tissue compared to cartilage from healthy controls. Although cartilage adjacent to repair tissue may be normal in thickness, it can demonstrate altered collagen composition.

There are several options for long head of the biceps (LHB) tenodesis and yet no standard of care. This technical note describes a cortical button technique for LHB tenodesis. We have taken the BicepsButton (Arthrex, Naples, FL) for distal biceps acute primary repair and applied it to the LHB. The biceps tenotomy is completed arthroscopically, and a standard subpectoral approach is used. The biceps is pulled out and whipstitched starting at the myotendinous junction and moving proximally. The humerus is drilled in a unicortical manner slightly larger than the tendon, and the button is passed through a small hole to the posterior cortex. A suture through the tendon provides additional fixation strength to the construct. This is an elegant and effective method of tenodesis that uses a smaller-diameter drill hole in the humerus. The goals of LHB tenodesis are to restore function, reduce pain, and improve cosmesis. This technique offers comparable function and cosmesis with the potential advantage of improving postoperative pain outcomes and lowering the rate of complications.

BACKGROUND: There is still little known regarding the effects of meniscus resection size on tibiofemoral stability. PURPOSE: To determine if partial medial meniscectomy of the posterior horn significantly alters tibiofemoral stability as measured by the anterior-posterior (AP) position and laxity of the medial femoral condyle. STUDY DESIGN: Controlled laboratory study. METHODS: Five cadaveric knees were dissected to the capsule, preserving all ligaments and the quadriceps tendon. Each specimen was first tested on a rig where the AP position and laxity of the medial femoral condyle were measured while a range of forces was applied from full extension to 90 degrees of flexion. Magnetic resonance imaging (MRI) at 3 tesla was then performed for baseline measurements of the meniscus before partial meniscectomy. Arthroscopic partial medial meniscectomy aimed at 30% of the posterior horn was then performed, followed by repeat mechanical testing and MRI. The sequence was then repeated for arthroscopic partial meniscectomy aimed at 60% and 100% of the posterior horn of the medial meniscus. RESULTS: The MRI analysis demonstrated that 22% +/- 9% of the original width of the posterior horn was removed at the first resection, 46% +/- 11% was removed at the second resection, and the third resection was 100% removal of the posterior horn for all specimens. After 22% resection, no significant difference in AP laxity was observed. A statistically significant increase in AP laxity was observed with 46% resection under a 500-N compressive load compared with the intact meniscus. After full resection, significant increases in AP laxity were observed under a 50-N compressive load compared with the intact and 22% and 46% resections. The 22% resection had similar AP positions as the intact knee, whereas the 46% resection and 100% removal of the posterior horn had statistically further posterior AP positions than the intact knee. CONCLUSION: Partial medial meniscectomy with >/=46% resection of the original width of the posterior horn significantly altered the AP position of the medial femoral condyle and also increased laxity. CLINICAL RELEVANCE: These mechanical changes may lead to abnormal cartilage loading and early osteoarthritis.

Background: Allografts offer potential advantages over autografts in anterior cruciate ligament reconstruction (ACLR), including the absence of donor site morbidity, shorter operative times, improved cosmesis, and easier rehabilitation. There is limited and conflicting outcome data for ACLR with tibialis anterior allograft. The purpose of this study was to evaluate the functional outcomes of ACLR with tibialis anterior allograft. Methods:We retrospectively evaluated primary ACL reconstructions using tibialis anterior allograft between January 2004 and December 2006. Clinical outcomes were measured by KT-1000 arthrometry, and International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores. Results: 19 patients were available for follow-up at a mean of 2.7 years (range: 2.0 to 3.2). One patient experienced a traumatic re-rupture that required revision and another patient was advised to undergo revision reconstruction for a failed graft. Based on IKDC and Lysholm scoring, 12 patients (63%) had good or excellent results, 4 (21%) patients had fair results, and 3 (16%) patients had poor results. The mean side-to-side difference was 2.7mm (0 to 8.2) and the mean decrease in Tegner activity level was 1.4 (0 to 6). Conclusion:An alarming number of patients demonstrated residual laxity after ACL reconstruction with tibialis anterior allograft. We recommend against using tibialis anterior allograft as a first choice graft for high demand patients.

Popliteal cysts are known to be associated with intra-articular pathology, which must be addressed to prevent cyst recurrence. Indications for popliteal cyst excision include cases in which the popliteal cyst does not respond to conservative treatment or arthroscopic intervention or cases in which an underlying cause cannot be found. Several techniques have been described to excise these cysts. Traditionally, open techniques have been associated with cyst recurrence. More recently, arthroscopic cystectomy has been described. However, the risk of recurrence persists because arthroscopy may not afford complete surgical excision. This technical note presents an open posterior technique for popliteal cyst excision that allows for better visualization and complete removal of the cyst while minimizing the risk of neurovascular complications and soft-tissue damage. It is a safe, effective, and straightforward method to achieve symptomatic relief for refractory popliteal cysts.

OBJECTIVES: To evaluate cartilage repair and native tissue using a three-dimensional (3D), radial, ultra-short echo time (UTE) (23)Na MR sequence without and with an inversion recovery (IR) preparation pulse for fluid suppression at 7 Tesla (T). METHODS: This study had institutional review board approval. We recruited 11 consecutive patients (41.5 +/- 11.8 years) from an orthopaedic surgery practice who had undergone a knee cartilage restoration procedure. The subjects were examined postoperatively (median = 26 weeks) with 7-T MRI using: proton-T2 (TR/TE = 3,000 ms/60 ms); sodium UTE (TR/TE = 100 ms/0.4 ms); fluid-suppressed, sodium UTE adiabatic IR. Cartilage sodium concentrations in repair tissue ([Na(+)](R)), adjacent native cartilage ([Na(+)](N)), and native cartilage within the opposite, non-surgical compartment ([Na(+)](N2)) were calculated using external NaCl phantoms. RESULTS: For conventional sodium imaging, mean [Na(+)](R), [Na(+)](N), [Na(+)](N2) were 177.8 +/- 54.1 mM, 170.1 +/- 40.7 mM, 172.2 +/- 30 mM respectively. Differences in [Na(+)](R) versus [Na(+)](N) (P = 0.59) and [Na(+)](N) versus [Na(+)](N2) (P = 0.89) were not significant. For sodium IR imaging, mean [Na(+)](R), [Na(+)](N), [Na(+)](N2) were 108.9 +/- 29.8 mM, 204.6 +/- 34.7 mM, 249.9 +/- 44.6 mM respectively. Decreases in [Na(+)](R) versus [Na(+)](N) (P = 0.0.0000035) and [Na(+)](N) versus [Na(+)](N2) (P = 0.015) were significant. CONCLUSIONS: Sodium IR imaging at 7 T can suppress the signal from free sodium within synovial fluid. This may allow improved assessment of [Na(+)] within cartilage repair and native tissue. KEY POINTS : * NaIR magnetic resonance imaging can suppress signal from sodium within synovial fluid. * NaIR MRI thus allows assessment of sodium concentration within cartilage tissue alone. * This may facilitate more accurate assessment of repair tissue composition and quality.

MRI has been shown to be both sensitive and specific in the diagnosis of partial thickness and full-thickness tears of the rotator cuff. Recognizing the pattern of a rotator cuff tear before surgery also provides useful information to the referring clinician as it can help in the selection of the type of surgery and lead to a better anatomic and biomechanical restoration of the cuff tendons. There is relative paucity of published reports exploring the performance of MRI in the recognition and classification of rotator cuff tears based on their morphological pattern. The purpose of this exhibit is: 1) to describe the geometric patterns of rotator cuff tears, 2) to illustrate the MR imaging appearance of the different patterns of rotator cuff tearing, 3) to describe the clinical significance of the different patterns in terms of treatment selection and outcome prediction. Characterization of the most common rotator cuff tear patterns will be presented including: crescent-shaped, U-shaped, L-shaped, and massive cuff tears. This will be followed by a guide that can be used to recognize these patterns on MRI utilizing the location as well as the size of the transverse and longitudinal components of the tear on surgically proven cases. Finally, a review of the different types of repairs currently available for each tear pattern will be presented including end-to-bone repair and margin convergence techniques as well as the expected postsurgical outcomes