Isolated rupture of the popliteus muscle with painful ossification in a skeletally immature athlete--a case report.

A case of an isolated popliteus tendon rupture occurring during sport in a skeletally immature athlete is presented. Treatment is not always clearly defined, as both nonoperative and operative have been successful. Because the outcome of rest from sports activity and failed trials of physical therapy allowed continued discomfort in the posterolateral aspect of the knee in this patient, repeat imaging and arthroscopy were performed. Part of the popliteus tendon was demonstrated to have ossified and was openly debrided. The remaining tendon was repaired to the lateral capsule. The patient went on to a full recovery and return to sport.

Management of acute glenohumeral dislocations.

The glenohumeral joint is the most commonly dislocated joint in the human body. Glenohumeral joint dislocations account for a large number of orthopedic consultations in inpatient and outpatient settings. A thorough workup is required for accurate diagnosis and appropriate treatment of this injury. Complete history and physical examination and radiographic studies are essential, and reduction should always be attempted. In this article, we review the literature for each phase of the workup for glenohumeral dislocation and describe the anatomy, biomechanics, and basic science of the injury. Featured is a detailed synopsis of the more commonly used reduction maneuvers plus their risks and success rates.

Biomechanical comparison of a knotless suture anchor with standard suture anchor in the repair of type II SLAP tears.

PURPOSE: To compare the biomechanical strength of knotless suture anchors and standard suture anchors in the repair of type II SLAP tears. METHODS: Five pairs of cadaveric shoulders (10 shoulders) were dissected free of soft tissue except for the glenoid labrum and long head of the biceps tendon. Type II SLAP tears were created and repaired with 1 of 2 anchors: the Mitek Lupine suture anchor or the Mitek Bioknotless suture anchor (DePuy Mitek, Raynham, MA). All specimens were preloaded to 10 N, and loaded for 25 cycles in 10 N increments to a maximum of 200 N. If specimens were still intact after 200 N, they were loaded to ultimate failure. The load at which 2 mm of gapping occurred, load to ultimate failure, mode of failure, and the number of cycles to failure were compared using the Wilcoxon signed-rank test. RESULTS: Load to 2-mm gapping was lower (P = .042) for knotless anchors (70 N) versus knotted anchors (104 N), with similar differences for ultimate failure (74 N v 132 N; P = .043), cycles to 2-mm gapping (133 v 219 cycles; P = .042), and cycles to failure (143 v 297; P = .043). Eight of 10 specimens failed at the soft tissue interface (4 knotless, 4 knotted) and 2 failed by anchor pullout (1 knotted, 1 knotless). CONCLUSIONS: The results of this study suggest that repair of a type II SLAP with a Mitek knotted suture anchor and mattress suture configuration through the biceps anchor is stronger than repair with a Mitek knotless suture anchor. The most likely method of repair failure was at the suture-soft tissue interface regardless of the type of anchor used. The application of a suture anchor that requires arthroscopic knot tying may be preferable to a knotless anchor for the surgical repair of type II SLAP tears. CLINICAL RELEVANCE: Repair of type II SLAP tears with knotless suture anchors may allow for the avoidance of arthroscopic knot tying but is weaker than repair with standard suture anchors.

Cyclic loading of 3 Achilles tendon repairs simulating early postoperative forces.

BACKGROUND: The abstract goes here and covers two columns. Accelerated rehabilitation has been advocated after Achilles tendon repair, but it produces significant forces at the repair site. The abstract goes here and covers two columns. HYPOTHESIS: Stresses applied to the repaired Achilles tendon simulating postoperative forces may exceed the strength of some repairs. STUDY DESIGN: Controlled laboratory study. METHODS: Fifteen Achilles tendons were incised 4 cm proximal to the calcaneal insertion, then were repaired using either a percutaneous, 4-strand Krackow, or an epitendinous augmented 4-strand Krackow technique. Tendons were cyclically loaded to 1000 cycles each at 100, 190, and 369 N. The number of cycles to initial gapping, 5-mm gapping, and total failure were compared using Mann-Whitney U tests with adjustments for multiple comparisons. RESULTS: Gap resistance was significantly greater for augmented Krackow repairs (2208 cycles to initial gapping) versus nonaugmented repairs (502 cycles, P = .024) and for nonaugmented Krackow repairs versus percutaneous repairs (5 cycles, P = .024). All percutaneous repairs failed during the 100-N cycling (102 +/- 135 cycles). All nonaugmented Krackow repairs failed during the 190-N cycles (total cycles to failure: 1268 +/- 345). All augmented Krackow repairs were intact (no gapping) after the 190-N cycles. Four failed during 369-N cycling (total cycles to failure, 2017 +/- 11), and 1 remained intact for 3000 cycles. CONCLUSION: Epitendinous cross-stitch weave augmentation of Achilles tendon repairs significantly increased repair strength and gap resistance. CLINICAL RELEVANCE: Epitendinous cross-stitch weave augmentation of Achilles tendon repairs may better allow for early stretching and ambulation after Achilles tendon repair.

Single-row modified mason-allen versus double-row arthroscopic rotator cuff repair: a biomechanical and surface area comparison.

PURPOSE: The purpose of this study was to compare the time-zero biomechanical strength and the surface area of repair between a single-row modified Mason-Allen rotator cuff repair and a double-row arthroscopic repair. METHODS: Six matched pairs of sheep infraspinatus tendons were repaired by both techniques. Pressure-sensitive film was used to measure the surface area of repair for each configuration. Specimens were biomechanically tested with cyclic loading from 20 N to 30 N for 20 cycles and were loaded to failure at a rate of 1 mm/s. Failure was defined at 5 mm of gap formation. RESULTS: Double-row suture anchor fixation restored a mean surface area of 258.23 +/- 69.7 mm(2) versus 148.08 +/- 75.5 mm(2) for single-row fixation, a 74% increase (P = .025). Both repairs had statistically similar time-zero biomechanics. There was no statistical difference in peak-to-peak displacement or elongation during cyclic loading. Single-row fixation showed a higher mean load to failure (110.26 +/- 26.4 N) than double-row fixation (108.93 +/- 21.8 N). This was not statistically significant (P = .932). All specimens failed at the suture-tendon interface. CONCLUSIONS: Double-row suture anchor fixation restores a greater percentage of the anatomic footprint when compared with a single-row Mason-Allen technique. The time-zero biomechanical strength was not significantly different between the 2 study groups. This study suggests that the 2 factors are independent of each other. CLINICAL RELEVANCE: Surface area and biomechanical strength of fixation are 2 independent factors in the outcome of rotator cuff repair. Maximizing both factors may increase the likelihood of complete tendon-bone healing and ultimately improve clinical outcomes. For smaller tears, a single-row modified Mason-Allen suture technique may provide sufficient strength, but for large amenable tears, a double row can provide both strength and increased surface area for healing.

Determination of anterior labral repair stress during passive arm motion in a cadaveric model.

PURPOSE: The actual forces encountered at the labrum after anterior labral repair have yet to be quantified. The purpose of this study was to determine the amount of force experienced at the glenoid-labrum interface with passive range of motion after an isolated Bankart repair and Bankart repair with capsular shift. METHODS: In 12 fresh-frozen cadaveric shoulders, anterior-inferior labral tears were created and then instrumented with a modified load cell. The labral lesions were repaired with either an anatomic "labral only" technique or a labral repair along with a capsular shift by use of a transglenoid technique. Shoulders were then taken through a series of movements (forward flexion, abduction, external rotation, and abduction and then external rotation) simulating passive range-of-motion rehabilitation while force measurements were taken. Maximum force (in Newtons) on the simulated repairs was recorded. RESULTS: The forces experienced at the labrum showed a statistically significant difference between the group that underwent anatomic "labral only" repair and the group that underwent labral repair with capsular shift. The greatest mean force experienced (17.7 N) was in shoulders undergoing the labral repair with capsular shift with the arm in abduction and external rotation. CONCLUSIONS: In a transglenoid suture repair technique, the forces experienced at the repair site were significantly less than those determined by previous authors to be necessary to result in failure of the Bankart repair. The results of this study show that the forces experienced at the glenoid-labrum interface are higher when a capsular shift is included with a labral repair as opposed to labral repair alone. This difference was statistically significant. CLINICAL RELEVANCE: These data suggest that early postoperative rehabilitation may safely allow greater passive range of motion than is presently accepted.

A biomechanical comparison of the modified Mason-Allen stitch and massive cuff stitch in vitro.

PURPOSE: The suture-tendon interface is generally regarded as the weak link in rotator cuff fixation. High rates of failure in arthroscopic rotator cuff repair have led to a search for strong yet easy-to-perform suture configurations. The goal of this study was to compare the strength of 2 commonly used suture configurations, the modified Mason-Allen stitch and the massive cuff stitch, when suture-anchored into bone. METHODS: Fourteen sheep shoulders were harvested and the infraspinatus tendon isolated. Each infraspinatus tendon was split in half longitudinally along the axis of its fibers to yield 2 tendon-bone specimens per shoulder, for a total of 28 specimens. Each split tendon was then repaired by use of a double-loaded suture anchor with a modified Mason-Allen and simple suture in one specimen and the massive cuff stitch in the other. Each specimen was initially cyclically loaded on a vertical MTS uniaxial load frame (MTS Systems, Eden Prairie, MN) under force control from 5 to 30 N at 0.25 Hz for 20 cycles. Each specimen was then loaded to failure under displacement control at a rate of 1 mm/s. Peak-to-peak displacement, cyclic elongation, ultimate tensile load, stiffness, and mode of failure were recorded. A repeated-measures analysis of variance was performed, with an alpha level of significance set at P < .05. RESULTS: No statistically significant difference was found with regard to ultimate load to failure between the modified Mason-Allen stitch (110.4 +/- 55.1 N) and massive cuff stitch (116.4 +/- 37.9 N). In addition, no statistically significant difference was found with regard to cyclic elongation, peak-to-peak displacement, or initial displacement. The most common mode of failure for both suture configurations was suture pullout. CONCLUSIONS: The modified Mason-Allen stitch and massive cuff stitch yield similar biomechanical profiles when suture-anchored into bone. CLINICAL RELEVANCE: The massive cuff stitch may be a simpler and biomechanically equivalent alternative to the modified Mason-Allen stitch in arthroscopic rotator cuff repair.