Evaluation of Rotator Cuff Augmentation of Proximal Humerus Fracture Fixation.

Proximal humerus fractures represent one of the most common fractures in the elderly, and are increasingly treated with surgical fixation. Suture augmentation attaching the rotator cuff to the plate has been advocated to combat varus collapse and other associated complications. The objective of this study was to evaluate the contribution of rotator cuff augmentation to stability of proximal humerus fracture fixation. Twelve shoulder specimens from six cadavers underwent simulated two-part and three-part proximal humerus fractures. Matched specimens from the same cadaver were randomized to suture augmentation with locking plate fixation vs. locking plate fixation alone. Greater tuberosity fragment displacement was recorded during cyclic rotational strain of the glenohumeral joint. Greater tuberosity displacement in the two-part fracture model trended towards greater motion without suture augmentation, but did not reach statistical significance (0.032 + 0.012 mm vs. 0.213 + 0.109 mm, p = 0.130). In the three-part fracture model, there was a statistically significant decrease in fracture displacement in the presence of suture augmentation (0.068 + 0.025 mm vs. 2.392 + 0.373 mm, p < 0.001). No specimens demonstrated premature failure during cyclic loading. Suture augmentation of locking plate fixation of three-part proximal humerus fractures results in decreased fracture displacement than locked plating alone, during rotational stresses simulating in vivo rotator cuff deformation forces. (Journal of Surgical Orthopaedic Advances 31(2):119-122, 2022).

Prevalence of femoroacetabular impingement in younger patients undergoing total hip arthroplasty.

The pathogenesis of hip arthrosis is complex with many risk factors. Femoroacetabular impingement abnormalities are thought to be a factor. To determine the prevalence of femoroacetabular impingement in younger patients who had undergone hip arthroplasty, the authors reviewed preoperative radiographs to determine radiographic indices of femoroacetabular impingement in 142 patients (92 men and 50 women) younger than 50 years old and who had undergone hip replacement. The average age of the patients was 43.4 years. The center-edge angle (Wiberg), the alpha angle (Nötzli), and the sacrococcygeal-symphysis distance were measured. The range of a sacrococcygeal-symphysis distance in both men and women was used to identify retroverted acetabuli in properly centered radiographs. In this population, radiographic signs of cam-type femoroacetabular impingement were prevalent in patients younger than 50 years old who had undergone hip arthroplasty. Ninety-two (65%) patients had an abnormal alpha angle indicating cam impingement: 63 men (68%, alpha angle ≥69°) and 29 women (58%, alpha angle ≥51°). Sixteen patients (11%) had signs of a retroverted acetabulum, suggesting pincer impingement. Of these, 11 had an abnormal alpha angle. Sixteen patients had hip dysplasia; of these, 10 had an abnormal alpha angle. Patients presenting with hip pain, minimal osteoarthritic changes, and indices of femoroacetabular impingement may be suitable candidates for early operative intervention to decompress the impingement that may potentially retard or arrest the progression of arthrosis in these patients.

Evaluation and treatment of acute and chronic injuries to the capsular ligaments of the knee.

Injury to the capsular ligaments of the knee commonly occurs in conjunction with cruciate ligament injury. An untreated grade III sprain can lead to recurrent meniscal injury, failure of cruciate ligament reconstruction, and arthrosis. Careful clinical examination is necessary to identify injuries to discrete ligaments and estimate the severity of injuries not discernable on imaging studies. A classification system of capsular injury is useful to link the diagnosis to a treatment algorithm. Anatomically based surgical procedures for acute and chronic sprains of the posteromedial, anterolateral, and posterolateral capsular structures have been proven in long-term outcome studies. The goal is to restore the anatomy by repair (for an acute sprain) or capsular shift (for a chronic sprain), rather than to substitute extra-articular tendon routing.

Normal anatomy and biomechanics of the knee.

Functionally, the knee comprises 2 articulations-the patellofemoral and tibiofemoral. Stability of the joint is governed by a combination of static ligaments, dynamic muscular forces, meniscocapsular aponeurosis, bony topography, and joint load. The surgeon is ill equipped to undertake surgical treatment of a dislocated knee without a sound footing in the anatomic complexities of this joint. We review the normal anatomy of the knee, emphasizing connective tissue structures and common injury patterns.

Surgical treatment of chronic posterolateral rotatory instability of the knee using capsular procedures.

Chronic posterolateral rotatory instability of the knee was introduced as a diagnostic classification by Hughston and associates in the early 1970s and occurs as a result of dysfunctional healing of a strained arcuate complex, causing a patulous posterolateral capsuloligamentous complex to exist. This capsular redundancy allows varying degrees of recurvatum and adduction instability during single-limb stance. Eradication of the redundant pouch with a capsular shift-type reconstruction has been shown to eliminate the instability and hold up under long-term follow-up studies. Understanding the complex normal and injured anatomy of the posterolateral corner of the knee is essential for effective reconstruction of this instability.