Knee flexor function 2 years after anterior cruciate ligament reconstruction with semitendinosus-gracilis autografts.

PURPOSE: This retrospective study evaluated the knee flexor function of 20 patients at 25.8 +/- 5 months after anterior cruciate ligament reconstruction with use of a semitendinosus-gracilis (STG) autograft. METHODS: Clinical examinations included instrumented isometric testing, conventional and prone isokinetic testing, hop testing, knee arthrometry, modified visual analog scale leg sensation evaluation, and International Knee Documentation Committee (IKDC) Subjective Knee and Current Health Evaluations. Paired t tests were used to evaluate side-to-side differences, and multiple regression analysis related these findings to knee function (P < .05). RESULTS: Involved side active knee flexion was decreased by 8.2 degrees +/- 5 degrees. Involved side isokinetic knee flexor work was decreased by 76.7 +/- 118 J at 60 degrees/sec during conventional testing and was decreased by 94.4 +/- 107 J and 86.3 +/- 115 J at 60 degrees/sec and 180 degrees/sec, respectively, during prone testing. Isometric testing at 90 degrees and 120 degrees flexion in internal and neutral tibial rotation, respectively, revealed decreased involved side knee flexor torque > or = 13.2 +/- 12 Nm. Sensation scores revealed a mean 24% difference from the uninvolved side (range, 0% to 80%). Multiple regression revealed that instrumented isometric testing at 90 degrees knee flexion with neutral tibial rotation and the role physical score predicted 62% (R2 = .62) of involved side forward hop capability (P < .0001). Self-reported activity level and isokinetic work (60 degrees/sec) predicted 69% (R2 = .69) of involved side lateral hop capability (P < .0001). Sensation, role physical score, and prone isokinetic peak torque (180 degrees/sec) predicted 80% (R2 = .80) of involved side medial hop capability (P < .0001). CONCLUSIONS: Two years after surgery, functionally significant knee flexor strength deficits remain. Prone isokinetic knee flexor work at 60 degrees /sec, isometric knee flexor torque at 90 degrees flexion-neutral tibial rotation, and sensation score were related to patient function 2 years after anterior cruciate ligament reconstruction with an STG autograft. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

A biomechanical comparison of Bosworth and poly-L lactic acid bioabsorbable screws for treatment of acromioclavicular separations.

PURPOSE: The purpose of this study was to determine the failure load of intact coracoclavicular ligaments and the pullout strength of a poly-L lactic acid screw (PLLA, Linvatec, Largo, FL) compared with a titanium screw (Bosworth, Stryker Howmedica Osteonics, Allendale, NJ) in the repair of fifth-degree acromioclavicular separations. TYPE OF STUDY: Biomechanical cadaveric study. METHODS: The ultimate tensile strength of coracoclavicular ligaments was determined using a servohydraulic testing machine (MTS, Eden Prairie, MN) by creating grade V acromioclavicular separations. Titanium Bosworth screws and Linvatec PLLA screws were placed across the reduced coracoclavicular joint and through the base of the coracoid process of right and left matched cadaveric shoulder specimens, respectively. The axial pullout strength was determined by MTS uniaxial tensile testing along the screw axis to determine the ultimate fixation failure load at a rate of 1 mm/second. RESULTS: Intact coracoclavicular ligaments required an axial load of 340.15 +/- 100.77 N to fail. The bioabsorbable PLLA screw provided fixation strength that was significantly less than the Bosworth screw fixation strength: 272.01 +/- 63.26 and 367.01 +/- 111.54 N, respectively (P < .05, paired t test). CONCLUSIONS: The titanium Bosworth screw restored strength to the acromioclavicular joint equivalent to the intact coracoclavicular ligament; however, the bioabsorbable PLLA screw fixation was significantly weaker than the intact ligaments and the Bosworth repair. CLINICAL RELEVANCE: Titanium Bosworth screws supply more strength of fixation in grade V acromioclavicular separations than the PLLA screw tested in this study.

Transfer of the long head of the triceps tendon for irreparable rotator cuff tears.

This study presents the clinical and anatomic findings of the use of the long head of the triceps tendon for treatment of massive, irreparable rotator cuff tears. The clinical study included 19 shoulders in 18 patients with a minimum followup of 2 years who were prospectively reviewed. All patients had preoperative and postoperative functional evaluations using the UCLA scoring system. The anatomic study included 20 upper extremities that had been injected with Microfil. All patients in the clinical study were satisfied with their outcome. There was an improvement in the UCLA pain and function scores. The long head of the triceps tendon is a myotendinous vascularized transfer that is a useful reconstructive procedure in patients with massive, irreparable rotator cuff tears that continue to be symptomatic despite conventional attempts at repair.

Determining the relationship of the axillary nerve to the shoulder joint capsule from an arthroscopic perspective.

BACKGROUND: The axillary nerve is out of the field of view during shoulder arthroscopy, but certain procedures require manipulation of capsular tissue that can threaten the function or integrity of the nerve. We studied fresh cadavers to identify the course of the axillary nerve in relation to the glenoid rim from an intra-articular perspective and to determine how close the nerve travels in relation to the glenoid rim and the inferior glenohumeral ligament. METHODS: We dissected nine whole-body fresh-tissue shoulder joints and exposed the axillary nerve through a window in the inferior glenohumeral ligament. Then we cut coronal sections through the glenoid fossa of ten unembalmed, frozen shoulder specimens after the axillary nerve had been stained with Evans blue dye. All specimens were studied with the joint secured in the lateral decubitus position used for shoulder arthroscopy. RESULTS: Microsurgical dissection through the inferior glenohumeral ligament from within the joint capsule revealed the axillary nerve as it traversed the quadrangular space. In each dissection, the teres minor branch was the closest to the glenoid rim. The coronal sectioning of the unembalmed shoulder specimens demonstrated that the closest point between the axillary nerve and the glenoid rim was at the 6 o'clock position on the inferior glenoid rim. At this position, the average distance between the axillary nerve and the glenoid rim was 12.4 mm. The axillary nerve lay, throughout its course, at an average of 2.5 mm from the inferior glenohumeral ligament. CONCLUSIONS: We used two novel approaches to map the axillary nerve from an intra-articular perspective. Our analysis of the position of the nerve with use of these methods provides the shoulder arthroscopist with essential information regarding the location, route, and morphology of the nerve as it passes inferior to the glenoid rim and shoulder capsule.

A reusable suture anchor for arthroscopy psychomotor skills training.

For residents to adequately develop the early arthroscopy psychomotor skills required to better learn how to manage the improvisational situations they will encounter during actual patient cases, they need to experience sufficient practice repetitions within a contextually relevant environment. Unfortunately, the cost of suture anchors can be a practice repetition-limiting factor in learning arthroscopic knot-tying techniques. We describe a technique for creating inexpensive reusable suture anchors and provide an example of their application to repair the anterior glenoid labrum during an arthroscopy psychomotor skills laboratory training session.

Magnetic resonance imaging analysis of the subacromial space in the impingement sign positions.

External shoulder impingement is commonly diagnosed by passively moving the shoulder into various positions of elevation and internal rotation in order to perform impingement sign maneuvers. There is a lack of agreement among clinicians regarding the positions of the anatomic structures in the subacromial space when these maneuvers are performed. The purpose of this study was to use magnetic resonance imaging to identify and measure the changes in anatomic structures in the subacromial space as the arm was moved from complete rest to 160 degrees of forward flexion during the Neer and Hawkins impingement sign maneuvers. Ten subjects with normal shoulders (mean age, 32 years) were studied. The acromiohumeral interval was smallest with the arm at the side (mean, 6.4 mm) and progressively increased as the arm was elevated from 90 degrees to 160 degrees (mean, 7.7-14.2 mm). In no instance was the rotator cuff found to be in contact with the anterior acromion. The rotator cuff insertion appeared to be in closest proximity to the anteroinferior acromion, not at full elevation (Neer sign position), but at 90 degrees of flexion (Hawkins sign position). Our data suggest that a clinically positive Hawkins sign is consistent with external shoulder impingement. Clinical suspicion that mechanisms other than impingement may be involved, particularly if the Neer impingement sign is also positive, is nonetheless advised.