The management of moderate to large engaging Hill-Sachs lesions is controversial and surgical options include remplissage, allograft reconstruction, and partial resurfacing arthroplasty. Few in-vitro studies have quantified their biomechanical characteristics and none have made direct comparisons. The purpose of this study was to compare joint stability and range of motion (ROM) among these procedures using an in-vitro shoulder simulator. It was hypothesized that all procedures would prevent defect engagement, but allograft and partial resurfacing would most accurately restore intact biomechanics; while remplissage would provide the greatest stabilization, possibly at the expense of motion. Eight cadaveric shoulders were tested on an active in-vitro shoulder simulator. Each specimen underwent testing in 11 conditions: intact, Bankart lesion, Bankart repair, and two unrepaired Hill-Sachs lesions (30% & 45%) which were then treated with each of the three techniques. Anterior joint stability, ROM in extension and internal-external rotation, and glenohumeral engagement were assessed. Stability was quantified as resistance, in N/mm, to an anteriorly applied load of 70N.Purpose
Method
The remplissage procedure may be performed as an adjunct to Bankart repair to address an engaging Hill-Sachs defect. Clinically, it has been reported that the remplissage procedure improves joint stability but that it may also restrict shoulder range of motion. The purpose of this biomechanical study was to examine the effects of the remplissage procedure on shoulder motion and stability. We hypothesized that the remplissage procedure would improve stability and prevent engagement but may have a deleterious effect on motion. Eight cadaveric forequarters were mounted on a custom biomechanical testing apparatus which applied simulated loads independently to the rotator cuff muscles and to the anterior, middle and posterior deltoid. The testing conditions included: intact shoulder, Bankart defect, Bankart repair, 2 Hill-Sachs defects (15%, 30%) with and without remplissage. Joint range of motion and translation were recorded with an optical tracking system. Outcomes measured were internal-external rotation range of motion in adduction and 90 combined abduction, extension range of motion and stability, quantified in terms of joint stiffness and engagement, in abduction.Purpose
Method
The remplissage technique of insetting the infraspinatus tendon and posterior joint capsule into an engaging Hill-Sachs lesion has gained in popularity. However, a standardized technique for suture anchor and suture placement has not been defined for this novel procedure. The purpose of this biomechanical study was to compare three remplissage techniques by evaluating their effects on joint stiffness and motion. Cadaveric forequarters (n=7) were mounted on a custom active biomechanical shoulder simulator. Three randomly ordered techniques were conducted: T1- anchors in the valley of the defect, T2- anchors in the rim of the humeral head; T3- anchors in the valley with medial suture placement. The testing conditions included: intact, Bankart, Bankart repair, and 15% & 30% HS lesions with repairs (T1, T2, T3). Outcome measures including internal-external range of motion and stability were recorded. Stability was quantified in terms of glenohumeral joint stiffness against an externally applied anterior force of 70N.Purpose
Method
Coracoid transfer is an effective reconstructive procedure for complex glenohumeral joint instability. Recently, the congruent-arc Latarjet procedure has been described which orients the coracoid graft undersurface flush to the glenoid articular margin. The purported advantage of this modification is that the radii of curvature of the coracoid undersurface and the anterior glenoid rim are believed to be similar, and therefore, congruent. The purpose of this study was to determine the dimensions of the coracoid and to compare the radius of curvature (ROC) of the coracoid undersurface to the ROC of the intact glenoid and various glenoid bone-loss scenarios. Thirty-four CT-based 3D models of the shoulder were examined using commercially available software. The mean dimensions of the coracoid were determined and the ROC was calculated for the coracoid undersurface, the intact glenoid as well as 20%, 35% and 50% anterior glenoid bone-loss scenarios. Intra and inter-rater statistics were calculated.Purpose
Method
The aim was to evaluate the Intraobserver and Interobserver reliability of Pelvic Incidence as a fundamental parameter of sagittal spino-pelvic balance in patients with spondylolisthesis compared to controls with Idiopathic Adolescent Scoliosis. A blinded test retest study including multi-surgeon assessment of Pelvic Incidence in patients with spondylolisthesis and Idiopathic Adolescent Scoliosis was carried out. We assessed the agreement between the pelvic incidence measurements using the Bland and Altman method and mean differences (95% confidence interval) are reported. Forty patients seen at Starship Children’s Hospital between 1992 – 2003 by two spinal surgeons were retrospectively identified. The main group had 20 patients with spondylolisthesis (Isthmic and/or Dysplastic types) and the control group consisted of 20 patients with Idiopathic Adolescent Scoliosis. Five observers with different levels of experience included the two orthopaedic surgeons, one fellow, one senior trainee and one non-trainee registrar. Prior to the initial test phase, a consensus-building session was carried out. All five observers arrived at a standardised method for measuring the Pelvic Incidence. In the test phase randomly ordered lateral lumbosacral radiographs were independently evaluated by the five observers and pelvic incidence was measured. Assessment of the Pelvic Incidence was repeated one week later in the re-test phase. The radiographs were presented in a randomly pre-assigned order. Bland and Altman plots were constructed and mean differences (95% confidence interval) reported to evaluate the agreement between the Pelvic Incidence measurements among the five independent observers. All analysis was performed on the statistical software package SAS. The spondylolisthesis group had 11 (55%) males and 9 (45%) females with an average age of 14 ± 4.2. 2 patients had high-grade (Meyerding Class III, IV, V) and 16 had low-grade (Meyerding Class I, II) spondylolisthesis. 2 patients were post-reduction of spondylolisthesis. In the Scoliosis group there were 2 (10%) males and 18 (90%) females with an average age of 15 ± 2.9. There was no significant difference between male and females pelvic incidence measurement (60° ± 18.7° vs. 57° ± 14.6°, Scoliosis patients had a significantly smaller pelvic incidence than spondylolisthesis patients. The interobserver reliability of the pelvic incidence measurement was excellent across both groups. The intraobserver reliability was good with only one observer in each group demonstrating a marginally significant difference. Pelvic incidence is therefore a reliable measurement which can be used as a predictor in progression of spondylolisthesis.
Thirty-four patients representing 58% of the study group had a definitive dignosis made. Fourteen patients (24%) had Scheuerman’s disease, seven (12%) were dignosed with spondylolisthesis and five (8.5%) had a painful scoliosis. Only one patient had osteomyelitis. We did not identify any patients with a tumor. Patients older than 10 years were almost twice as likely to have a positive diagnosis than those under 10 years of age. There was no single reliable clinical sign or symptom that would help make the diagnosis. Significant haematological abnormalities were only found in one patient who was diagnosed with sacral osteomyelitis. Plain radiographs alone provided the diagnosis in 14 (23.5%) patients. Bone scan, CT and MRI were of variable diagnostic value.
Spinal epidural sepsis is more widely recognised with MRI. Treatment includes antibiotics, multisystem support and drainage of pus. Neurological loss will often be stabilised but dramatic recovery is infrequent, explaining the importance of early intervention. This series highlights a very sinister spectrum of spinal infective disease despite ideal traditional treatment for spinal skeletal infection. This is a retrospective case series review of five patients. All patients presented with regional spinal pain, fever and regional musculoskeletal infective foci (e.g. discitis). Mild neurological abnormality existed in three patients. Rapid multisystem collapse occurred with the need for ventilatory support, despite institution of appropriate antibiotic treatment for all patients. All had grown Staphylococcus Aureus from blood cultures. Subsequent extensive quadriparesis/plegia developed, and repeat imaging demonstrated wide spread epidural pus in the cervical spine. Surgical treatment was considered but not performed when the prognosis was so poor neurologically and medically, and when the widespread epidural pus was so inaccessible. All patients died rapidly upon withdrawal of supportive treatment. This paper describes a sinister spectrum of spinal infection with catastrophic complications despite “appropriate” treatment for previously diagnosed spinal foci infection. Positive blood cultures and fever alert to these dangers, and multisystem collapse heralded the development of cervical epidural infection. Possible interventions include early MRI scanning of the whole spine, more aggressive (than traditionally accepted) surgical treatment of infective foci in the spine in these circumstances, and minimally invasive cervical canal decompression procedures with multiple laminotomies.