Surgical treatment of displaced proximal humerus fractures with a short intramedullary nail.

BACKGROUND: The Polaris nail is an intramedullary device for treating displaced proximal humerus fractures with few published studies to support its use. Results of a consecutive series of patients treated with the Polaris nail are presented. METHODS: Eighteen patients with a mean age of 71 years (range, 37-84) were treated for twelve 2- and six 3-part fractures. Radiographic results for all patients were evaluated. Thirteen patients with an average follow-up of 42 months (range, 24-84) were available for functional evaluation. RESULTS: Seventeen of 18 patients healed. Postoperatively, the neck/shaft angle collapsed an average 11° (range, 5-30°) into varus. Nine of 18 patients had final neck/shaft angles <120° and were considered radiographic malunions. The mean Constant and American Shoulder and Elbow Surgeons (ASES) scores were 61 (range, 20-100) and 67 (range, 10-100), respectively. Forward elevation averaged 118°. Patients had an average 5/8 positive rotator cuff signs. Seven patients underwent reoperation for loss of fixation or prominent hardware, and 1 required revision to a hemiarthroplasty. CONCLUSION: This study shows a higher than reported percentage of unsatisfactory results using the Polaris nail. The device violates the rotator cuff and is unable to resist the deforming forces that can lead to loss of fixation and varus collapse.

Failure of coracoclavicular artificial graft reconstructions from repetitive rotation.

PURPOSE: To assess how suture type and suture construct in an augmented Weaver-Dunn reconstruction affect coracoclavicular sling failure and rotary stability. METHODS: Fifteen cadaveric shoulders were tested in rotation about the long axis of the clavicle with 10 lb of simulated arm weight. The clavicle was rotated 50 degrees about its long axis, and the applied torque was recorded. Next, modified Weaver-Dunn reconstruction was conducted. Two types of coracoclavicular sling (opposed drill holes through the clavicle and complete loop around the clavicle) were tested by use of 3 different sutures (FiberWire [Arthrex, Naples, FL], Mersilene tape [Ethicon, Somerville, NJ], and braided polydioxanone [PDS] [Ethicon]). For each sling-suture combination, the joint was retested over 50 degrees of rotation and then cycled over 40 degrees of rotation for 15,000 cycles or until failure. RESULTS: After modified Weaver-Dunn reconstruction with either sling construct, mean torque over 50 degrees of acromioclavicular rotation was significantly reduced in posterior (P < .0001) and anterior (P < .0001) rotation, with any suture material tested. When the coracoclavicular sling was placed through opposed drill holes, no wear to the bone or suture was observed. When the sling material was looped around the clavicle, FiberWire and PDS resulted in abrasion of soft tissue and periosteum. In all cases sawing motion between bone and suture was observed at the coracoid. The FiberWire itself failed at a mean of 8,213 cycles. Some wear was noted in the Mersilene tape. PDS suture showed no wear. CONCLUSIONS: In a cadaveric model of modified Weaver-Dunn reconstruction, a coracoclavicular suture loop was used to augment coracoacromial ligament transfer. Suture loops secured around the entire clavicle were shown to contribute to increased abrasive wear. Securing suture loops through opposed drill holes in the clavicle resulted in decreased abrasive wear. CLINICAL RELEVANCE: Proper selection of suture type and suture construct may affect the failure rate of augmented Weaver-Dunn reconstructions.

Distal biceps tendon repair: a cadaveric analysis of suture anchor and interference screw restoration of the anatomic footprint.

BACKGROUND: Distal biceps tendon repair with interference screw or double suture-anchor fixation are 2 successful techniques performed with either 1- or 2-incision approaches. No study has examined the accuracy and quality of the repaired tendon footprint with these devices and approaches. HYPOTHESIS: A 2-incision approach will allow a more anatomic repair of the distal biceps footprint compared with a 1-incision anterior approach. Fixation technique will affect insertional footprint location and footprint contact area. STUDY DESIGN: Controlled laboratory study. METHODS: After randomization, 36 distal biceps repairs were performed on human cadaveric upper extremity specimens, with 1- or 2-incision approaches and with fixation devices of either two 5.5-mm suture anchors or an 8-mm interference screw. Native and repaired footprint areas and centroid location were calculated with a 3-dimensional digitizer. RESULTS: Interference screw repair had the smallest footprint area (135 mm(2)) compared with suture anchor repair (197 mm(2)) and the native tendon (259 mm(2)) (P = .013). The 2-incision approach repaired the footprint to a more posterior and anatomic position (2.5 mm) than a 1-incision approach (P = .001). The fixation device did not affect footprint location significantly. CONCLUSION: Suture anchor repair more closely re-creates the footprint area on the radial tuberosity of the native distal biceps tendon compared with the interference screw repair. A 2-incision approach more closely re-creates footprint position compared with the 1-incision approach. CLINICAL RELEVANCE: A 2-incision approach with double suture-anchor fixation may yield a more anatomic distal biceps repair based on reproduction of the footprint compared with a 1-incision approach.

In situ transtendon repair outperforms tear completion and repair for partial articular-sided supraspinatus tendon tears.

This biomechanical study compared 2 repair techniques for high-grade, partial, articular-sided supraspinatus tendon tears of the rotator cuff: transtendon in situ repair and tear completion with repair. Standardized, 50% partial, articular-sided supraspinatus lesions were created in 10 pairs of matched fresh, frozen cadaveric shoulders: 10 underwent partial lesion repair with an in situ transtendon technique using 2 suture anchors. In the contralateral 10 shoulders, the partial lesion was converted to a full-thickness tear and repaired with a double-row technique, using 4 suture anchors. Cyclic loading to failure of the supraspinatus tendon was performed using a material testing machine. Gap formation was measured for each rotational position and each incremental load. The in situ transtendon repair had statistically significant less gapping (P = .0001) and higher mean ultimate failure strength (P = .0011) than the double-row repair. In situ transtendon repair was biomechanically superior to tear completion for partial, articular-sided supraspinatus tears.