Cross-Sectional Area of the Rotator Cuff Muscles in MRI - Is there Evidence for a Biomechanical Balanced Shoulder?

OBJECTIVE To provide in-vivo evidence for the common biomechanical concept of transverse and craniocaudal force couples in the shoulder that are yielded by both the rotator cuff muscles (RCM) and the deltoid and to quantitatively evaluate and correlate the cross-sectional areas (CSA) of the corresponding RCM as a surrogate marker for muscle strength using MRI. MATERIALS AND METHODS Fifty patients (mean age, 36 years; age range, 18-57 years; 41 male, 9 female) without rotator cuff tears were included in this retrospective study. Data were assessed by two readers. The CSA (mm2) of all rotator cuff muscles was measured on parasagittal T1-weighted FSE sequence at two different positions (at the established "y-position" and at a more medial slice in the presumably maximal CSA for each muscle, i.e., the "set position"). The CSA of the deltoid was measured on axial intermediate-weighted FSE sequences at three positions. CSA measurements were obtained using 1.5 Tesla MR-arthrographic shoulder. Pearson's correlation for the corresponding CSA of the force couple as well as was the intraclass correlation coefficient for the inter- and intra-reader agreement was calculated. RESULTS The mean CSA was 770 mm2 (±167) and 841 mm2 (±191) for the supraspinatus (in the y- and set-positions, respectively) and 984 mm2 (±241) and 1568 mm2 (±338) for the infraspinatus. The mean CSA was 446 mm2 (±129) and 438 mm2 (±128) for the teres minor (in the y- and set-positions, respectively) and 1953 mm2 (±553) and 2343 mm2 (±587) for the subscapularis. The three measurements of the deltoid revealed a CSA of 3063 mm2 (±839) for the upper edge, 3829 mm2 (±836) for the lower edge and 4069 mm2 (±937) for the middle of the glenoid. At the set position Pearson's correlation of the transverse force couple (subscapularis/infraspinatus) showed a moderate positive correlation of r = 0.583 (p<0.0001) and a strong correlation when the CSA of the teres minor was added to the infraspinatus CSA (r = 0.665, p = 0.0008) and a strong positive correlation of the craniocaudal force couple (supraspinatus/deltoid) that ranged from r = 0.565-0.698 (p<0.0001). Inter-reader agreement (ranged from 0.841 to 0.997, p = 0.0007) and intra-reader agreement were excellent (ranged from 0.863 to 0.999, p = 0.0006). CONCLUSION The significant correlation of the CSA of the RCM that form the transverse (subscapularis/infraspinatus-teres minor) and craniocaudal (supraspinatus/deltoid) force couple measured by MR-arthrography supports the biomechanical concept of a dynamically balanced shoulder in patients with an intact rotator cuff

Impact of vertical and horizontal malrotation on measurements of anteroposterior radiographs of the scapula: need for standardized images in modern omometry

BACKGROUND An increasing number of parameters measured on anteroposterior radiographs are used for the evaluation of the bony geometry of the scapula. Inhomogeneous acquisition of images is common because of the lack of standardization in radiographic positioning. Images with malrotation around the horizontal axis of the scapula are particularly frequent. We hypothesized that malrotated images would result in large variations in measured radiographic parameters and that image standardization using qualitative and semiquantitative "omometric" criteria would decrease these variations in measurements. "Omometry" is a newly introduced umbrella term that contains all standardized measurements on plain radiographs of the shoulder, analogous to the term "coxometry," which is widely used for the radiographic assessment of the osseous pelvis and hip. METHODS In this experimental, cadaveric radiographic study, 7 dry-bone human scapula cadaveric specimens from anonymous donors were used to obtain 210 radiographs. We incrementally rotated (steps of 3°) every scapula around its horizontal and vertical axis, with a total range of 42° per each axis. Then, we measured 5 radiographic parameters on every image and observed their change with malrotation. Furthermore, we introduced 4 omometric criteria defining an appropriate (presence of ≥3 criteria) radiographic image to improve standardization of scapular image acquisition. RESULTS Overall, measured values remained stable within a narrow range of ±9° of malrotation. Beyond this range, values of all parameters significantly deviated (>±2°) from the initial value. Measurements on appropriate images were significantly less prone to deviation. Within the appropriate images, those with 4 criteria showed a higher specificity than those with 3 criteria. CONCLUSION There is significant variation in values of measured radiographic parameters on anteroposterior radiographs of the scapula with substantially malrotated images. With the use of the 4 newly introduced semiquantitative and qualitative omometric criteria, which define an appropriate image, reliability of the measured parameters can be significantly improved

Is the lateral extension of the acromion related to the outcome of shoulder injections?

OBJECTIVE To assess patients' outcomes after subacromial or glenohumeral injections based on the degree of lateral extension of the acromion. METHODS 307 patients were prospectively included after therapeutic fluoroscopy-guided subacromial (n = 148) or glenohumeral (n = 159) injections with anaesthetic and long-acting corticosteroids. Pre- and post-injection outcomes at 1 week and 1 month were obtained using the 11-point numerical rating scale (NRS) for pain. Lateral extension of the acromion was quantified and categorized by the critical shoulder angle (CSA) and the acromion index (AI) on anteroposterior conventional radiographs. RESULTS Patients' outcomes at 1 week and 1 month were significantly improved (p 35° (4.2 ± 2.6 vs. 3.2 ± 3.0, p = 0.04). A significant difference in the 1-month NRS change in pain scores is noted for smaller AIs after subacromial injection (4.3 ± 2.8 vs. 2.6 ± 2.9; p = 0.01). No significant association was noted between clinical outcome and the lateral extension of the acromion after glenohumeral joint injections. CONCLUSIONS A short lateral extension of the acromion was associated with better clinical outcomes in subacromial injection patients but not in glenohumeral injection patients. KEY POINTS • Patients' outcomes at 1 month improved significantly compared to baseline for subacromial injections. • Patients' outcomes at 1 month improved significantly compared to baseline for glenohumeral injections. • Short acromial lateralization was associated with better clinical outcome after subacromial injection. • The acromial lateralization was not associated with clinical outcome after glenohumeral injection

Salvage arthrodesis after failed total ankle replacement: Reconstruction with structural allograft and intramedullary nail

Treatment of failed total ankle arthroplasty is a challenge. To date, several revision modalities and techniques have been described, but there is still no ideal concept that fits for every patient. Surgical options comprise revision ankle arthroplasty, amputation, or salvage arthrodesis, with the latter being a viable approach because it has been proven to be reliable in achieving a stable and plantigrade foot. The goals of revision surgery include maximum pain relief, restoration of stability and length, and correction of alignment. When properly done, arthrodesis yields a significant improvement regarding pain and ensures stability and an adequate gait pattern. Massive bone loss associated with or without deformity of the hindfoot and/or coexisting subtalar osteoarthrosis pose specific problems. In such cases, tibiotalocalcaneal arthrodesis must be combined with reconstruction of the ankle region by filling the defect with a structural allograft. Among all the described techniques, the use of locked intramedullary nails offers several advantages, particularly in combination with allograft interposition

A biomechanical study comparing the mean load to failure of two different osteosynthesis techniques for step-cut olecranon osteotomy

Background Olecranon osteotomies are frequently used to expose distal humeral intraarticular fractures. The step-cut olecranon osteotomy (SCOOT) is an augmented version of the oblique olecranon osteotomy, which has recently been evaluated biomechanically with tension band wiring (TBW) fixation. However, complications with TBW are common. In this study, we, therefore, compared the mean load to failure of TBW with compression screws for SCOOT fixation. We hypothesized a higher load to failure for the compression screw group. Methods We performed a SCOOT on 36 Sawbones. Eighteen were fixed with TBW, and another 18 with two compression screws. The humeroulnar joint was simulated using an established test setup, which allows the application of triceps traction force through a tendon model to the ulna, while the humeroulnar joint is in a fixed position. Eight models of each fixation group were tested at 20°, and eight at 70° of flexion by isometrical loading until failure, which was defined as either a complete fracture or gap formation of more than 2 mm at the osteotomy site. Results At 20° of flexion, mean load to failure was similar between the TBW group (1360 ± 238 N) and the compression screw group (1401 ± 261 N) (P = .88). Also, at 70° of flexion, the mean load to failure was similar between the TBW group (1398 ± 215 N) and the compression screw group (1614 ± 427 N) (P = .28). Conclusions SCOOTs fixed with TBW and compression screws showed similar loads to failure. A SCOOT fixed with compression screws might be a valuable alternative for surgeons when treating intraarticular distal humeral fractures. However, future in vivo studies are necessary to confirm our results in a clinical setting

BiPOD arthroscopically assisted bidirectional stabilisation technique for high-grade acromioclavicular joint injury: two-year clinical and radiological outcomes.

PURPOSE The purpose of this study was to evaluate the intermediate-term clinical and radiological outcomes for acute, unstable acromioclavicular joint (ACJ) injuries treated with the arthroscopically assisted BiPOD stabilisation technique. METHODS Twenty-three patients who sustained acute, unstable ACJ injuries were included in this prospective study. We recorded demographics, injury classification, time to surgery, clinical scores, radiological outcomes and complications; each patient completed a minimum of 2 years post-operative observation. RESULTS Mean follow-up was 26 months (range, 24-34). Clinical outcomes scores demonstrated good 2-year results: relative Constant score, 97.9/100; ACJ Index, 89.4/100; Subjective Shoulder Value, 92.4/100 and Taft = 11.1/12. Final C-C distance showed a mean of 0.7 mm (SD ± 1.8 mm) at 2 years. Complication rate was 9%. CONCLUSION The BiPOD technique shows excellent, reliable intermediate-term results with a favourable complication rate compared to existing techniques; it provides a comprehensive surgical option for the stabilisation of acute ACJ injuries restoring both vertical and horizontal stability

Skiing and snowboarding related deep laceration injuries. A five-season cross-sectional analysis from a level-1 trauma centre in the Swiss Alps.

OBJECTIVES Lacerations comprise 5.6-33.6% of skiing/snowboarding related injuries. This study aimed to investigate the mechanism of injury and the location of these lacerations and propose preventive measures. METHODS After our state ethics committee approval, we retrospectively reviewed the medical records and surgical protocols of 46 patients (mean age (±SD) 34.6 (±15.3); 71.4% men) treated for severe skiing/snowboarding lacerations at our level-1 trauma centre between 2016 and 2021. Patients were asked to answer a questionnaire on their skiing experience, equipment used and the circumstances of the accident. RESULTS Lacerations around the hip, thigh, and knee accounted for 94%. The latter was the most common location (45%). Although 91.3% of patients wore appropriate clothing and full standard protection equipment, it did not offer any extra-resistance against skiing/snowboarding's edges. Skiers were more affected (91.3%) than snowboarders (8.7%). The most common mechanism of injury was inadvertent release of the bindings (52.2%), followed by insufficient ski level for the slope (21.7%) and collisions (17.4%). Long-term trends demonstrated an increasing incidence. CONCLUSION Identification of body areas at risk and the mechanisms of injury were the most significant findings of this work. These data encourage the development of specific injury prevention programs as the occurrence of these lesions tended to increase over the last few years. To reduce their incidence, we propose skiers to have their bindings regularly adjusted and manufacturers to develop cut-resistant skiwear. LEVEL OF EVIDENCE IV

Latissimus Dorsi Tendon transfer for treatment of irreparable posterosuperior rotator cuff tears: Long-term results at a minimum follow-up of ten years

BACKGROUND: Transfer of the latissimus dorsi tendon to the greater tuberosity of the humerus for treatment of an irreparable rotator cuff tear has been reported to yield good-to-excellent short to intermediate-term results in well-selected patients. The purpose of this study was to evaluate the long-term outcome of such transfers for irreparable posterosuperior rotator cuff tears to determine the durability of the results and to identify risk factors for an unfavorable outcome. METHODS: Fifty-seven shoulders in fifty-five patients (seventeen women and thirty-eight men with a mean age of fifty-six years) were managed with latissimus dorsi tendon transfer. Final follow-up was performed at a mean of 147 months. Outcome measures included the Constant score and the Subjective Shoulder Value (SSV). Osteoarthritis, the acromiohumeral distance, and the so-called critical shoulder angle were assessed on standardized radiographs. RESULTS: Forty-six shoulders in forty-four patients were available at the time of final follow-up. The mean SSV increased from 29% preoperatively to 70% at the time of final follow-up, the relative Constant score improved from 56% to 80%, and the pain score improved from 7 to 13 points (p &lt; 0.0001 for all). Mean flexion increased from 118° to 132°, abduction increased from 112° to 123°, and external rotation increased from 18° to 33°. Mean abduction strength increased from 1.2 to 2.0 kg (p = 0.001). There was a slight but significant increase in osteoarthritic changes. Inferior results occurred in shoulders with insufficiency of the subscapularis muscle and fatty infiltration of the teres minor muscle. Superior functional results were observed in shoulders with a small postoperative critical shoulder angle. CONCLUSIONS: Latissimus dorsi tendon transfer offered an effective treatment for irreparable posterosuperior rotator cuff tears, with substantial and durable improvements in shoulder function and pain relief. Shoulders with fatty infiltration of the teres minor muscle and insufficiency of the subscapularis muscle tended to have inferior results, as did those with a large critical shoulder angle. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence

Extra-articular step osteotomy of the olecranon: A biomechanical assessment

BACKGROUND Trans-olecranon chevron osteotomies (COs) remain the gold standard surgical approach to type C fractures of the distal humerus. This technique is associated with a high complication rate and development of an extra-articular olecranon osteotomy may be advantageous. The aim of this study was to compare the load to failure of COs with extra-articular oblique osteotomies (OOs) as well as modified, extra-articular step osteotomies (SOs). METHODS These three osteotomies and their subsequent fixation utilizing a standardized tension band wiring technique were tested in 42 composite analog ulnae models at 20° and 70° of flexion. Triceps loading was simulated with a servo hydraulic testing machine. All specimens were isometrically loaded until failure. Kinematic and force data, as well as interfragmentary motion were recorded. RESULTS At 70°, CO failed at a mean load of 963N (SD 104N), the OO at 1512N (SD 208N) and the SO at 1484N (SD 153N), (P<0.001). At 20°, CO failed at a mean load of 707N (SD 104N) and OO at 1009N (SD 85N) (P=0.006). The highest load to failure was observed for the SO, which was 1277N (SD 172N). The load to failure of the SO was significantly higher than the CO as well as the OO. CONCLUSION Extra-articular osteotomies showed a significantly higher load to failure in comparison to traditional CO. At near full extension (20° of flexion), this biomechanical advantage was further enhanced by a step-cut modification of the extra-articular oblique osteotomy

Early serum procalcitonin level after primary total hip replacement

BACKGROUND: Procalcitonin (PCT) is a useful surrogate marker for the differentiation of postoperative infection and unspecific inflammatory reaction after surgery. It is known that postoperative course of the PCT serum level varies with type of surgery. No data exists about the postoperative course of serum PCT levels after primary total hip replacement (THR). PURPOSE: To characterize early postoperative serum PCT levels in uneventful primary THR compared to postoperative levels of different frequently used inflammatory blood parameters. METHOD: We prospectively investigated 31 patients. Blood samples were taken preoperatively and for 5 days postoperatively. PCT levels were compared with C-reactive protein (CRP), interleukin-6 (IL-6), and blood leucocyte counts (WBC). RESULTS: In uneventful THR PCT levels showed a uniform low-level course with a peak at the second postoperative day. At the fifth day values returned to almost preoperative levels. On contrary, CRP levels remained high during the entire observational period. Only IL-6 levels showed a peak at postoperative day one with a quick and uniform return to preoperative levels. CONCLUSION: Similar to observations in cardiothoracic, intestinal, and neural surgeries, postoperative course of PCT after primary THR showed a uniform low-level course with a peak at the second postoperative day but below expected levels in systemic infections