Joint-preserving treatment for type 3 sequelae following fracture of the proximal humerus with small head fragments.

BACKGROUND: Although nonunions of the proximal humerus are rare, they cause significant disability to patients. Surgical reconstruction is challenging, especially with small and excavated head fragments. A promising surgical option is open reduction and stabilization using the Humerusblock device along with tension wires. The aim of this retrospective investigation was to evaluate the clinical and radiological results of this procedure. MATERIALS AND METHODS: Fifteen patients with symptomatic surgical neck nonunions were treated with open reduction and internal fixation using the Humerusblock device without bone grafting. All patients showed a loss of bone stock, leading to excavated head fragments. The mean interval from injury to the described treatment was 6.2 months (range, 3.4-10.7). At a mean follow-up of 40.5 months, the Constant-Murley score was documented, pain and patient satisfaction were evaluated using a visual analogue scale, and x-rays were taken in two planes. RESULTS: The patients' mean age was 69.7 years (range, 52-83). The mean Constant-Murley score improved from 24 points before surgery to 62 points at follow-up, which was an average of 80.8% of the score obtained for the contralateral arm. Radiological examination confirmed bony healing in 14 patients. All but one patient felt satisfied with the results. Three patients required revision surgery because of a hematoma, and early metal removal was performed in one patient because of infection. CONCLUSION: Nonunions of humeral surgical neck fractures can be successfully treated by fixation using the Humerusblock device along with tension wires without the need for additional bone grafting. Especially in patients with flat, concave head fragments, this procedure remains a promising reconstructive option to arthroplasty. LEVEL OF EVIDENCE: Level IV; Therapeutic retrospective case series.

Functional Outcomes in Individuals Undergoing Very Early (< 5 h) and Early (5-24 h) Surgical Decompression in Traumatic Cervical Spinal Cord Injury: Analysis of Neurological Improvement from the Austrian Spinal Cord Injury Study.

Our study aim was to assess the neurological outcomes of surgical decompression and stabilization within 5 and 24 h after injury. We performed a multi-center, retrospective cohort study in adolescents and adults 15-85 years of age presenting cervical spinal cord injury (CSCI) at one of 6 Austrian trauma centers participating in the Austrian Spinal Cord Injury Study (ASCIS). Neurological outcomes were measured using the American Spinal Injury Association Impairment Scale (AIS) grade according to the International Standards For Neurological Classification Of Spinal Cord Injury (ISNCSCI) form after at least 6 months of follow-up (FU). Of the 49 enrolled patients with acute CSCI, 33 underwent surgical decompression within 5 h (mean 3.2 h ± 1.1 h; very early group) after injury, and 16 underwent surgical decompression between 5 and 24 h (mean 8.6 h ± 5.5 h; early group). Significant neurological improvement was observed among the entire study population between the preoperative assessment and the FU. We identified a significant difference in the AIS grade at the last FU between the groups the using Jonckheere-Terpstra test for doubly ordered crosstabs (p = 0.011) and significantly different AIS improvement rates in the early group (Poisson model, p = 0.018). Improvement by one AIS grade was observed in 31% and 42% of the patients in the early and very early groups, respectively (p = 0.54). Improvement by two AIS grades was observed in 31% and 6% of the patients in the early and very early groups, respectively (p = 0.03; relative risk [RR], 5.2; 95% CI, 1.1-35). Improvement by three AIS grades was observed in 6% and 3% of patients in the early and very early groups, respectively (p = 1.0). Decompression of the spinal cord within 24 h after SCI was associated with an improved neurological outcome. No additional neurological benefit was observed in patients who underwent decompression within 5 h of injury.

Biomechanical Comparison of Sacral Fixation Characteristics of Standard S1-Pedicle Screw Fixation versus a Novel Constrained S1-Dual-Screw Anchorage in the S1-Pedicle and S1-Alar Bone.

STUDY DESIGN: Biomechanical Laboratory Study. OBJECTIVE: Analysis of the biomechanical characteristics of a novel sacral constrained dual-screw fixation device (S1-PALA), combining a S1-pedicle screw and a S1-ala screw, compared to a standard bicortical S1-pedicle screw (S1-PS) fixation. SUMMARY OF BACKGROUND DATA: Instrumented fusions to the sacrum are biomechanically challenging and plagued by a high risk of nonunion when S1-PS is used as the sole means of fixation. Thus, lumbopelvic fixation is increasingly selected instead, although associated with a reasonable number of instrumentation-related complications. METHODS: Around 30 fresh-frozen human sacral bones were harvested and embedded after CT scans. Instrumentation was conducted in alternating order with bicortical 7.0 mm S1-PS and with the S1-PALA including a S1-PS screw and a S1-ala screw, of 7.0 and 6.0 mm diameter, respectively. Specimens were subjected to cyclic loading with increasing loads (25-250 N) until a maximum of 2000 cycles or displacement >2 mm occurred. All implant sacral units (ISUs) were subject to coaxial pullout tests. Failure load, number of ISUs surpassing 2000 cycles, number of cycles, and loads at failure were recorded and compared. RESULTS: Donors' age averaged 77 ± 14.2 years, and BMD was 115 ± 64.8 mgCA-HA/ml. Total working length of screws implanted was 90 ± 8.6 mm in the S1-PALA group and 46 ± 5 mm in the S1-PS group (P = 0.0002). In the S1-PALA group, displacement >2 mm occurred after 845 ± 325 cycles at 149 ± 41 N compared to 512 ± 281 cycles at 106 ± 36 N in the S1-PS group (P = 0.004; P = 0.002). In coaxial pull-out testing, failure load was 2118.1 ± 1166 N at a displacement of 2.5 ± 1 mm in the S1-PALA group compared to 1375.6 ± 750.1 N at a displacement of 1.6 ± 0.5 mm in the S1-PS group (P = 0.0007; P = 0.0003). CONCLUSION: The novel sacral constrained dual-screw anchorage (S1-PALA) significantly improved holding strength after cyclic loading compared to S1-PS. The S1-PALA demonstrated mechanical potential as a useful adjunct in the armamentarium of lumbosacral fixations indicated in cases that need advanced construct stability, but where instrumentation to the ilium or distal dissection to S2 should be avoided. LEVEL OF EVIDENCE: N/A.

Leriche-Like Syndrome as a Delayed Complication Following Posterior Instrumentation of a Traumatic L1 Fracture: A Case Report and Literature Review.

STUDY DESIGN: Case report and review of literature. OBJECTIVE: Case report of an acute Leriche-like syndrome as an unusual complication after posterior transpedicular instrumentation of an L1 fracture. SUMMARY OF BACKGROUND DATA: Injuries to the aorta after pedicle screw placement are rare. Reports exist about acute hemorrhage, erosions, and pseudoaneurysm formation. METHODS: A 47-year-old female developed an acute occlusion of the infrarenal aorta after posterior transpedicular instrumentation of an L1 burst-fracture. The patient presented with increasing sensation of hypothermia in both lower extremities and cyanosis of the toes, as well as claudication-like symptoms 15 days after the initial surgery. CT angiography showed bicortical placement of the left pedicle screw at L2 with perforation of the anterior cortex of 2.5 mm and complete obliteration of the infrarenal aorta up to the bifurcation. RESULTS: The patient was treated with resection of the aorta and implantation of a silver graft prosthesis. Preoperative symptoms resolved immediately after surgery without reoccurrence. CONCLUSION: Although rare, the risk of iatrogenic injuries to the aorta during spine surgery exists, several complications have previously been described. However, this is the first report of an acute Leriche-like syndrome after posterior instrumentation of the spine. Whereas bicortical pedicle screw placement in selected cases of posterior spinal instrumentation is intended, one has to be aware of the possible risks, as in our case where an acute aortic obliteration was observed. Preoperative CT-based planning of surgery and profound knowledge of the neurovascular anatomy is mandatory. LEVEL OF EVIDENCE: 5.

Construct stability of an instrumented 2-level cervical corpectomy model following fatigue testing: biomechanical comparison of circumferential antero-posterior instrumentation versus a novel anterior-only transpedicular screw-plate fixation technique.

INTRODUCTION: A high rate of complications in multilevel cervical surgery with corpectomies and anterior-only screw-and-plate stabilization is reported. A 360°-instrumentation improves construct stiffness and fusion rates, but adds the morbidity of a second approach. A novel ATS-technique (technique that used anterior transpedicular screw placement) was recently described, yet no study to date has analyzed its performance after fatigue loading. Accordingly, the authors performed an analysis of construct stiffness after fatigue testing of a cervical 2-level corpectomy model reconstructed using a novel anterior transpedicular screw-and-plate technique (ATS-group) in comparison to standard antero-posterior instrumentation (360°-group). MATERIALS AND METHODS: Twelve fresh-frozen human cervical spines were mounted on a spine motion tester to analyze restriction of ROM under loading (1.5 Nm) in flexion-extension (FE), axial rotation (AR), and lateral bending (LB). Testing was performed in the intact state, and after instrumentation of a 2-level corpectomy C4 + C5 using a cage and the constructs of ATS- and 360°-group, after 1,000 cycles, and after 2,000 cycles of fatigue testing. In the ATS-group (n = 6), instrumentation was achieved using a customized C3-C6 ATS-plate system. In the 360°-group (n = 6), instrumentation consisted of a standard anterior screw-and-plate system with a posterior instrumentation using C3-C6 lateral mass screws. Motion data were assessed as degrees and further processed as normalized values after standardization to the intact ROM state. RESULTS: Specimen age and BMD were not significantly different between the ATS- and 360°-groups. After instrumentation and 2,000 cycles of testing, no specimen exhibited a ROM greater than in the intact state. No specimen exhibited catastrophic construct failure after 2,000 cycles. Construct stiffness in the 360°-group was significantly increased compared to the ATS-group for all loading conditions, except for FE-testing after instrumentation. After 2,000 cycles, restriction of ROM under loading in FE was 39.8 ± 30% in the ATS-group vs. 2.8 ± 2.3% in the 360°-group, in AR 60.4 ± 25.8 vs 15 ± 11%, and in LB 40 ± 23.4 vs 3.9 ± 1.2%. Differences were significant (p < 0.05). CONCLUSION: 360°-instrumentation resembles the biomechanical standard of reference for stabilization of 2-level corpectomies. An ATS-construct was also shown to confer high construct stiffness, significantly reducing the percentage ROM beyond that of an intact specimen after 2,000 cycles. This type of instrumentation might be a clinical valuable and biomechanically sound adjunct to multilevel anterior surgical procedures.

Impact of constrained dual-screw anchorage on holding strength and the resistance to cyclic loading in anterior spinal deformity surgery: a comparative biomechanical study.

STUDY DESIGN: Biomechanical in vitro laboratory study. OBJECTIVE: To compare the biomechanical performance of 3 fixation concepts used for anterior instrumented scoliosis correction and fusion (AISF). SUMMARY OF BACKGROUND DATA: AISF is an ideal estimate for selective fusion in adolescent idiopathic scoliosis. Correction is mediated using rods and screws anchored in the vertebral bodies. Application of large correction forces can promote early weakening of the implant-vertebra interfaces, with potential postoperative loss of correction, implant dislodgment, and nonunion. Therefore, improvement of screw-rod anchorage characteristics with AISF is valuable. METHODS: A total of 111 thoracolumbar vertebrae harvested from 7 human spines completed a testing protocol. Age of specimens was 62.9 ± 8.2 years. Vertebrae were potted in polymethylmethacrylate and instrumented using 3 different devices with identical screw length and unicortical fixation: single constrained screw fixation (SC fixation), nonconstrained dual-screw fixation (DNS fixation), and constrained dual-screw fixation (DC fixation) resembling a novel implant type. Mechanical testing of each implant-vertebra unit using cyclic loading and pullout tests were performed after stress tests were applied mimicking surgical maneuvers during AISF. Test order was as follows: (1) preload test 1 simulating screw-rod locking and cantilever forces; (2) preload test 2 simulating compression/distraction maneuver; (3) cyclic loading tests with implant-vertebra unit subjected to stepwise increased cyclic loading (maximum: 200 N) protocol with 1000 cycles at 2 Hz, tests were aborted if displacement greater than 2 mm occurred before reaching 1000 cycles; and (4) coaxial pullout tests at a pullout rate of 5 mm/min. With each test, the mode of failure, that is, shear versus fracture, was noted as well as the ultimate load to failure (N), number of implant-vertebra units surpassing 1000 cycles, and number of cycles and related loads applied. RESULTS: Thirty-three percent of vertebrae surpassed 1000 cycles, 38% in the SC group, 19% in the DNS group, and 43% in the DC group. The difference between the DC group and the DNS group yielded significance (P = 0.04). For vertebrae not surpassing 1000 cycles, the number of cycles at implant displacement greater than 2 mm in the SC group was 648.7 ± 280.2 cycles, in the DNS group was 478.8 ± 219.0 cycles, and in the DC group was 699.5 ± 150.6 cycles. Differences between the SC group and the DNS group were significant (P = 0.008) as between the DC group and the DNS group (P = 0.0009). Load to failure in the SC group was 444.3 ± 302 N, in the DNS group was 527.7 ± 273 N, and in the DC group was 664.4 ± 371.5 N. The DC group outperformed the other constructs. The difference between the SC group and the DNS group failed significance (P = 0.25), whereas there was a significant difference between the SC group and the DC group (P = 0.003). The DC group showed a strong trend toward increased load to failure compared with the DNS group but without significance (P = 0.067). Surpassing 1000 cycles had a significant impact on the maximum load to failure in the SC group (P = 0.0001) and in the DNS group (P = 0.01) but not in the DC group (P = 0.2), which had the highest number of vertebrae surpassing 1000 cycles. CONCLUSION: Constrained dual-screw fixation characteristics in modern AISF implants can improve resistance to cyclic loading and pullout forces. DC constructs bear the potential to reduce the mechanical shortcomings of AISF.

Clinical and computed tomography-radiologic outcome after bony glenoid augmentation in recurrent anterior shoulder instability without significant glenoid bone loss.

BACKGROUND: The presence of a significant bony defect in anterior shoulder instability cases warrants glenoid reconstruction surgery typically by means of an autograft. Some surgeons use the same graft techniques even in the absence of a significant bony defect, thus augmenting the glenoid surface. The goal of this study is to investigate the clinical and computed tomography-radiologic outcome after glenoid augmentation surgery. METHODS: Between 2006 and 2011, 11 patients with recurrent anterior shoulder instability and glenoid bone loss of 5% or less were treated with an iliac crest autograft. Of the patients, 9 were available for follow-up at a mean of 34.6 months (range, 12 to 80 months), including apprehension testing, Western Ontario Shoulder Instability Index, Rowe score, Simple Shoulder Value, and 3-dimensional computed tomography examination. RESULTS: The mean Rowe score achieved was 85.0 points (range, 51 to 100 points); Simple Shoulder Value, 80.5 points (range, 30 to 100 points); and Western Ontario Shoulder Instability Index, 373.5 points (range, 61 to 878 points). Two patients reported a recurrence of instability, and one featured a positive apprehension test. The mean glenoid surface area was 96.5% (95% confidence interval [CI], 95.5% to 97.4%) preoperatively, increased after graft implantation to 119.5% (95% CI, 105.6% to 133.3%), and decreased to 102.8% (95% CI, 98.6% to 107.1%) at follow-up, concordant to an intact glenoid surface area. From preoperatively to follow-up, the mean increase in glenoid surface area was 6.4% (95% CI, 2.1% to 10.6%; P = .008); in concavity diameter, 2.0 mm (95% CI, -0.9 to 4.9 mm; P = .168); in concavity depth, 0.9 mm (95% CI, 0.3 to 1.5 mm; P = .005); and in concavity retroversion, 2.4° (95% CI, -1.2° to 6.1°; P = .178). CONCLUSION: Because of anatomic bony remodeling processes, glenoid augmentation surgery seems to be subject to extensive graft osteolysis and, consequently, unsatisfactory clinical outcome in terms of stability in some cases.

Reverse shoulder arthroplasty combined with latissimus dorsi transfer using the bone-chip technique.

PURPOSE: Reverse shoulder arthroplasty (RSA) can restore active elevation in rotator-cuff-deficient shoulders. However, RSA cannot restore active external rotation. The combination of latissimus dorsi transfer with RSA has been reported to restore both active elevation and external rotation. We hypothesised that in the combined procedure, harvesting the latissimus dorsi with a small piece of bone, leads to good tendon integrity, low rupture rates and good clinical outcome. METHODS: Between 2004 and 2010, 13 patients (13 shoulders) were treated with RSA in combination with latissimus dorsi transfer in a modified manner. The mean follow-up was 65.4 months, and the mean age at index surgery was 71.1 years. All patients had external rotation lag sign and positive hornblower's sign, as well as radiological signs of cuff-tear arthropathy (Hamada 3, 4 or 5) and fatty infiltration grade 3 according to Goutallier et al. on magnetic resonance imaging (MRI). The outcome measures included the Constant Murley Score, University of California-Los Angeles (UCLA) shoulder score, Simple Shoulder Test (SST), visual analogue scale (VAS) and the Activities of Daily Living Requiring External Rotation (ADLER) score. Tendon integrity was evaluated with dynamic ultrasound. All patients were asked at final follow-up to rate their satisfaction as excellent, good, satisfied or dissatisfied. RESULTS: The overall mean Constant-Murley Shoulder Outcome Score (CMS) improved from 20.4 to 64.3 points (p < 0.001). Mean VAS pain score decreased from 6.8 to 1.1 (p < 0.001)., mean UCLA score improved from 7.9 to 26.4 (p < 0.001), mean SST score improved from 2.3 to 7.9 (p < 0.001) and mean postoperative ADLER score was 26 points. The average degree of abduction improved from 45° to 129° (p < 0.001), the average degree of anterior flexion improved from 55° to 138° (p < 0.001) and the average degree of external rotation improved from -16° to 21° (p < 0.001). Eight patients rated their results as very satisfied, three as satisfied and two as dissatisfied. CONCLUSION: This modified technique, which avoids cutting the pectoralis major tendon and involves harvesting the tendon together with a small piece of bone, leads to good or even better functional results compared with the results reported in the literature, and also has high patient satisfaction and low failure rates.

Reverse shoulder arthroplasty in revision of failed shoulder arthroplasty-outcome and follow-up.

PURPOSE: The number of shoulder arthroplasties has increased over the last decade, which can partly be explained by the increasing use of the reverse total shoulder arthroplasty technique. However, the options for revision surgery after primary arthroplasty are limited in cases of irreparable rotator cuff deficiency, and tuberosity malunion, nonunion, or resorption. Often, conversion to a reverse design is the only suitable solution. We analysed the functional outcome, complication rate and patient satisfaction after the revision of primary shoulder arthroplasty using an inverse design. METHODS: Over a ten-year period 57 patients underwent revision surgery for failed primary shoulder arthroplasty using a reverse design. Of the 57 patients, 50 (mean age, 64.2 years) were available after an average follow-up of 51 months. Clinical evaluation included the Constant Murley Score, the UCLA score, and the Simple Shoulder Test, whereas radiological evaluation included plain radiographs in standard projections. Patients were also requested to rate their subjective satisfaction of the final outcome as excellent, good, satisfied or dissatisfied. RESULTS: Compared to the preoperative status, the overall functional outcome measurements based on standardised outcome shoulder scores improved significantly at follow-up. The overall mean Constant Murley score improved from 18.5 to 49.3 points, the mean UCLA score improved from 7.1 to 21.6 points, and the mean simple shoulder test improved from 1.2 to 5.6 points. The average degree of abduction improved from 40 to 93° (p < 0.0001), and the average degree of anterior flexion improved from 47 to 98° (p < 0.0001). The median VAS pain score decreased from 7 to 1. Complications occurred in 12 cases (24 %).A total of 32 (64 %) patients rated their result as good or excellent, six (12 %) as satisfactory and 12 (24 %) as dissatisfied. CONCLUSION: In revision shoulder arthroplasty after failed primary shoulder arthroplasty an inverse design can improve the functional outcome, and patient satisfaction is usually high. However, the complication rate of this procedure is also high, and patient selection and other treatment options should be carefully considered.