A new arthroscopic technique to determine anterior-inferior glenoid bone loss: validation of the secant chord theory in a cadaveric model.

PURPOSE: The accuracy of a previously described method using the glenoid bare spot (GBS) as a reference point was compared with a new method using the secant chord theory (SCT), which relies on the circular geometry of the inferior glenoid to calculate bone loss. METHODS: In 7 embalmed cadaveric shoulders a digital image of the glenoid face was used to calculate the area of the best-fit circle of the inferior glenoid. Osteotomy templates from the 3-o'clock to 6-o'clock position were created to make a simulated anterior-inferior bone defect of 12.5% and 25% of the area of the circle. Measurements were taken with an arthroscopic probe from 2 simulated posterior portal positions (9 and 10 o'clock) by use of 2 techniques-SCT and GBS-in the intact, 12.5% loss, and 25% loss states. RESULTS: In the intact state, measurements showed a mean SCT loss of 4.1% and GBS loss of 4.4%. In the 12.5% loss state, mean percent bone loss with GBS was 23.1% compared with 14.8% with SCT (P = .0001) at the 10-o'clock portal and 22.2% compared with 15.9% (P = .006) at the 9-o'clock portal. In the 25% loss state, mean percent bone loss with GBS was 31.5% compared with 26.6% with SCT (P = .002) at the 10-o'clock portal and 30.4% compared with 28.9% (P = .48) at the 9-o'clock portal. CONCLUSIONS: The SCT is shown to be a more accurate method of determining glenoid bone loss in an arthroscopic model; however, additional mathematic calculations are necessary. As shown in the intact state, there is an inherent small error of approximately 4% when arthroscopically determining bone loss. CLINICAL RELEVANCE: The technique may aid the clinician in quantifying glenoid bone loss and help determine when bone augmentation may be advisable.

Posterior wall blowout in anterior cruciate ligament reconstruction: avoidance, recognition, and salvage.

Posterior wall blowout is an important potential source of anterior cruciate ligament reconstruction failures that can be avoided if surgeons adhere to proper technique and are vigilant in confirming appropriate femoral tunnel placement. This article reviews techniques for avoidance, recognition, and salvage of posterior wall blowouts in anterior cruciate ligament reconstruction surgery.

Evaluation and treatment of osteochondritis dissecans lesions of the knee.

Osteochondritis dissecans (OCD) is a condition affecting the subchondral bone of joints with secondary effects on articular cartilage that results in pain, effusions, loose-body formation, and mechanical symptoms. Left untreated, OCD can lead to the development of degenerative arthritis secondary to joint incongruity and abnormal wear patterns. This article discusses the etiology of knee OCD lesions, clinical presentation, proper evaluation, and treatment options. Treatment of OCD may include nonoperative measures or operative procedures ranging from drilling or fixation of fragments to complex reconstruction procedures such as autologous chondrocyte implantation, osteochondral autograft, and fresh osteochondral allograft. Physicians must consider many factors, including the patient's age and skeletal maturity, as well as size, location, and stability of OCD lesions to determine the proper course of treatment.

Measurement of glenoid bone loss: a comparison of measurement error between 45 degrees and 0 degrees bone loss models and with different posterior arthroscopy portal locations.

BACKGROUND: Osteotomies at an angle of 45 degrees to the long axis of the glenoid were originally used in a cadaveric model to simulate the bone loss that can occur clinically in anterior instability of the shoulder. However, this type of glenoid defect is not consistent with the usual clinical scenario, in which bone loss occurs nearly parallel (at 0 degrees) to the long axis of the glenoid. PURPOSE: Our objectives were to compare the amount of glenoid bone loss measured after a 45 degrees glenoid osteotomy with that after a 0 degrees osteotomy and to determine differences in bone loss measurement from 2 different posterior shoulder portals. STUDY DESIGN: Controlled laboratory study. METHODS: Glenoids of 14 embalmed cadaveric shoulders (mean age, 81 years; range, 56-90) were mounted in a custom shoulder holder, and 2 posterior portals (2 and 3 o'clock) were fixed into place. The area of a best-fit circle of the inferior portion of the glenoid was digitally calculated, and 2 sequential osteotomies of 12.5% and 25% of anteroinferior glenoid bone loss area were created. Two different types of osteotomies were created: group 1, "inverted-pear" bone loss (45 degrees to the long axis of the glenoid); and group 2, "clinical" bone loss osteotomy (0 degrees to the long axis of the glenoid). Measurements of bone loss were performed based on the bare spot method from 2 simulated posterior portals at 2 and 3 o'clock using a calibrated probe and digital calipers. The osteotomy was measured in 3 different locations (upper, middle, and lower thirds). RESULTS: In the 12.5% bone loss model, bone loss measurements for both groups were significantly higher than expected (22.2%-23.1% in group 1, 17.4%-17.9% in group 2; P = .031-.049). In the 25% bone loss model, the mean measured bone loss was 27.8% in group 1 and 27.5% in group 2; however, bone loss measurements varied significantly in group 1 based on measurement location along the osteotomy (upper third, 12.3%; middle third, 31.5%; lower third, 39.8% loss) (P = .01-.0001). In group 2, the bone loss measurements were less varied (23.5%-30.3%). There were no differences between the location of the posterior portal (2 vs 3 o'clock) in determination of glenoid bone loss for both the 12.5% and 25% osteotomies. CONCLUSION: Glenoid bone loss determination in a 45 degrees osteotomy model significantly overestimates the amount of true glenoid bone loss. However, in a 0 degrees clinical bone loss simulation model, the arthroscopic bare spot method of bone loss determination was sufficiently accurate at all 3 areas (upper, middle, and lower third) of bone loss. Both the 2-o'clock and 3-o'clock posterior portals were accurate to determine the amount of glenoid bone loss as referenced from the bare spot. CLINICAL RELEVANCE: Arthroscopic determination of glenoid bone loss is more accurate than what has been previously described with the 45 degrees simulation model. Measurement of glenoid bone loss from either the 2-o'clock or 3-o'clock posterior portal is accurate in a clinical bone loss model.

Creation of transosseous patellar tunnels during extensor mechanism repair: technical note.

Transosseous patellar tunnels commonly are used in the repair of acute or chronic patellar tendon or quadriceps tendon ruptures. Commonly, a small diameter (2.0-3.5 mm) drill bit is used to create these drill tunnels. However, drill bits are relatively brittle and susceptible to breakage. The use of a larger diameter smooth Steinmann pin (3/32") is recommended to create transosseous patellar tunnels to eliminate this potential complication.

Lateral meniscus allograft biologic glenoid arthroplasty in total shoulder arthroplasty for young shoulders with degenerative joint disease.

To avoid potential polyethylene problems in younger shoulders with degenerative joint disease (DJD) requiring arthroplasty, lateral meniscus allograft (LMA) was used as a biologic resurfacing of the glenoid. We report preliminary, short-term results of this technique in a younger, higher-demand population. The shoulders of 20 men and 10 women, with an average age of 42 years (range, 18 to 52 years), underwent total shoulder arthroplasty with a LMA. A metallic prosthesis was used on the humerus. Etiology of the DJD was osteoarthritis in 16, postinstability surgery in 8, traumatic in 4, and failed open reduction with internal fixation in 2. Twenty-two (73%) had previous shoulder surgery. Preoperative average scores were American Shoulder and Elbow Surgeons (ASES), 38; Simple Shoulder Test (SST), 3.3; and Visual Analogue Scale (VAS), 6.4. The average active forward elevation was 96 degrees and external rotation was 26 degrees . Average follow-up was 18 months (range, 12 to 48 months). Postoperative average scores were ASES, 69; SST, 7.8; and VAS, 2.3. Active forward elevation was 139 degrees and external rotation was 53 degrees . All were significant improvements (P < .02). Most (94%) would have the surgery again. Radiologic evaluation at 1 year revealed an average joint space of 1.8 mm on anteroposterior views and 1.6 mm on axillary views. Five complications (17%) occurred within the first postoperative year, all of which required reoperation. Pain resulted in 2 conversions to a polyethylene glenoid. Polyethylene glenoids in young shoulders risk early failure. For young, high-demand shoulders with DJD requiring arthroplasty, the LMA shows promise. Most problems presented within the first year. Although not perfect, it provided significant pain relief, range-of-motion gains, and patient satisfaction without the risk of poly wear or loosening. Longer-term follow-up will be required to determine ultimate durability.

Treatment options for articular cartilage defects of the knee.

The treatment of symptomatic articular cartilage defects of the knee has evolved tremendously in the past decade. Previously, there were limited treatment options available to patients who suffered from either partial-thickness or full-thickness cartilage lesions. Because articular cartilage has a limited capacity for healing, patients were often treated symptomatically until they became candidates for osteotomy or total joint replacement. Recently, both reparative and restorative procedures have been developed to address this significant source of morbidity in young active patients. Microfracture is a reparative technique that induces a healing response to occur in an area of articular cartilage damage. Osteochondral autografts and allografts in addition to autologous chondrocyte implantation are restorative techniques aimed at recreating a more normal articular surface. Both types of procedures have been developed to alleviate the symptoms associated with focal chondral defects, as well as limit their potential to progress to a diffuse degenerative arthritis. Treatment can vary depending on both cartilage defect and patient factors. This article summarizes the various treatment options that have recently become available.