Benjamin Shaffer

Graft-tunnel mismatch in endoscopic anterior cruciate ligament reconstruction: A new technique of intraarticular measurement and modified graft harvesting

The purpose of this study was to determine the incidence of bitunnel interference fixation and accurate femoral insertion site targeting using a modified technique of endoscopic anterior cruciate ligament (ACL) reconstruction. Thirty-four consecutive central-third bone-patellar tendon-bone autograft modified endoscopic ACL reconstructions were prospectively studied. A new technique was used intraoperatively to directly measure (a) intraarticular (graft) distance (IAD) and (b) patellar tendon graft length, thereby allowing calculation of optimal tibial tunnel length for each case. Accuracy of guide pin placement through this tibial tunnel into the proposed femoral insertion site was assessed, as was the ability to achieve interference fixation in both tunnels (minimum of 20 mm bone interference fixation within the tibial tunnel). A new technique for patellar tendon-bone harvesting and proximal graft fixation to address graft mismatch is described. The average IAD from tibial origin to femoral ACL insertion measured 26.3 +/- 3.0 mm (range 21-33). The average patellar tendon length (LP) was 48.4 +/- 6.0 mm (range 40-63). The average calculated tibial tunnel length (TT) necessary to achieve bitunnel fixation (TT > or = LP + 20 - IAD) was 42.1 +/- 5.3 mm (range 36-57). Establishment of the calculated tibial tunnel length was achieved in 25 cases (74%) (no graft-tunnel mismatch). Graft-tunnel mismatch, in which the tibial tunnel could not be established to the length calculated necessary to accommodate a minimum of 20 mm of bone graft, occurred in nine cases (26%). Graft-tunnel mismatch occurred more frequently in patients whose patellar lengths were > or = 50 mm (p < 0.005), but was not found to correlate specifically to IAD. Recession of the graft up into the femoral tunnel allowed accommodation of the mismatched graft (bitunnel interference screw fixation) in these nine cases, averaging 22.0 +/- 2.98 mm (range 16-29 mm) of available distal bone block fixation. Tibial tunnel fixation of > or = 20 mm was achieved in 30 patients (88%), 18 mm in two, 17 mm in one, and 16 mm in one. Measurement error resulted in inadequate distal graft accommodation in four patients in whom error averaged 3 mm. Targeting of the femoral insertion site guide pin was achieved without requiring any knee manipulation for all cases. Patellar tendon graft protrusion through the tibial tunnel and potentially suboptimal graft fixation poses a frequent problem during endoscopic ACL reconstruction.(ABSTRACT TRUNCATED AT 400 WORDS)

Infraspinatus Muscle-splitting Incision in Posterior Shoulder Surgery An Anatomic and Electromyographic Study

Standard posterior shoulder surgical approaches include infraspinatus tendon detachment and infraspinatus-teres minor interval development. Cadav eric and clinical investigation of a new infraspinatus- splitting approach to the posterior glenohumeral joint was undertaken to assess efficacy in providing expo sure, preserving tendon attachment, and avoiding neu rologic compromise. Infraspinatus musculotendinous and neural anatomy was examined in 20 cadavers. Four patients with posterior shoulder instability underwent posterior capsulorrhaphy through this infraspinatus- splitting approach, followed by electrodiagnostic test ing. Infraspinatus muscle was bipennate in all speci mens, the tendinous interval an average 14 mm inferior to the scapular spine at the glenoid rim. The infraspinatus-splitting interval bisected the posterior glenoid rim at its midpoint, whereas the infraspinatus- teres minor interval crossed the glenoid rims lower quarter. The suprascapular nerve provided sole inner vation to the infraspinatus muscle in all specimens, en tering the infraspinous fossa at the notch as a single trunk 22 mm medial to the glenoid rim. Minimum branch ing variability was observed. Electrodiagnostic testing showed no evidence of axonal damage or muscle de nervation in either infraspinatus pennate bundle. Lim iting infraspinatus-splitting dissection medially to 1.5 cm from the posterior glenoid rim prevents damage to any interval-crossing suprascapular nerve branches. Pos terior shoulder surgery through a horizontal, longitudi nal infraspinatus tendon-splitting approach provides ex cellent exposure of posterior capsule, labrum, and glenoid, without requiring tendon detachment or caus ing neurologic compromise.

Acute Fracture through an Intramedullary Stabilized Chronic Tibial Stress Fracture in a Basketball Player: A Case Report and Literature Review

The tibia shaft is the most common location for stress fractures in athletes. The majority of tibial stress fractures, particularly those of the posteromedial cortex, are responsive to rest, with or without immobilization. However, lesions located in the anterior cortex of the central tibia have been found to have a poor tendency to heal. These stress fractures occur on the tension side of the bone and are prone to delayed union, nonunion, and complete fracture. Radiographically, a defect of the anterior tibial cortex, “the dreaded black line,” warns the treating physician of potentially prolonged and unpredictable healing. Treatment strategies for these fractures vary, and surgical intervention often becomes necessary for those recalcitrant to conservative measures. Intramedullary nailing is an established approach for treating the delayed or nonunited tibial stress fracture. This report describes a fracture following intramedullary rodding of a chronic tibial stress fracture, a complication not previously reported.

Complications in Shoulder Arthroscopy

Complications following shoulder arthroscopy are relatively uncommon. In 1986 Small first reported 40 complications in a review of over 14,000 procedures, for an overall complication rate of 0.28%.1 In 1988 he noted a slightly higher rate among experienced arthroscopists, 0.78% of 1184 cases reviewed.2 Most complications were due to staple use, reflex sympathetic dystrophy, and hemarthrosis. Subsequent studies have suggested the complication rate is probably higher. Berjano et al. in 1998 reporting an incidence of 10.6% in their 179 cases.3 Complications can be generally divided into those that occur during any shoulder arthroscopy and those that are are procedure specific. This chapter reviews complications of shoulder arthroscopy, with emphasis on how to avoid them.