There is a wide range of reports on the prevalence of neurological injuries during scoliosis surgery, however this should depend on the subtypes and severity of the deformity. Furthermore, anterior versus posterior corrections pose different stresses to the spine, further quantifications of neurological risks are presented. Neuromonitoring data was prospectively entered, and the database between 2006 and 2012 was interrogated. All deformity cases under the age of 21 were included. Tumour, fracture, infection and revision cases were excluded. All “red alerts” were identified and detailed examinations of the neuromonitoring records, clinical notes and radiographs were made. Diagnosis, deformity severity and operative details were recorded. 2290 deformity operations were performed: 2068 scoliosis (1636 idiopathic, 204 neuromuscular, 216 syndromic, and 12 others), 89 kyphosis, 54 growing rod procedures, and 80 operations for hemivertebra. 696 anterior and 1363 posterior operations were performed for scoliosis (8 not recorded), and 38 anterior and 51 posterior kyphosis correction. 67 “red alerts” were identified, there were 14 transient and 6 permanent neurological injuries. 62 were during posterior stage (24 idiopathic, 21 neuromuscular, 15 syndromic (2 kyphosis), 1 growing rod procedure, 1 haemivertebra), and 5 were during anterior stage (4 idiopathic scoliosis and 1 syndromic kyphosis). Average Cobb angle was 88°. 1 permanent injuries were during correction for kyphosis, and 5 were for scoliosis (4 syndromic, 1 neuromuscular, and 1 anterior idiopathic). Common reactions after “red alerts” were surgical pause with anaesthetic interventions (n=39) and the Stagnara wake-up test (n=22). Metalwork was partially removed in 20, revised in 12 and completely removed in 9. 13 procedures were abandoned. The overall risk of permanent neurological injuries was 0.2%, the highest risk groups were posterior corrections for kyphosis and scoliosis associated with a syndrome. 4% of all posterior deformity corrections had “red alerts”, and 0.3% resulted in permanent injuries; compared to 0.6% “red alerts” and 0.3% permanent injuries for anterior surgery. The overall risk for idiopathic scoliosis was 0.06%.
The limitation is it cannot be reinflated and cannot be used in patients with fractures.
Shoulder rotator cuff tears can be very debilitating and painful. Whilst massive tears may defy attempts at surgical repair due to the size of the defect, various biological materials have been proposed to reinforce tenuous repairs; initial results have been promising. It has been suggested that these materials may be used to bridge defects in the rotator cuff as a ‘patch’ or ‘interposition implant’ to provide pain relief and even offer some hope of functional recovery. A porcine dermal collagen implant (Permacol ©) has been engineered and introduced for the repair and reconstruction of soft tissues in the human body. In orthopaedics, it has been successfully used in the reinforcement and augmentation of rotator cuff repairs by suturing it over the repaired tendon. Proper et al reported good short term results in using this implant to bridge defects in massive rotator cuff tears and suggested it was good solution for this group of patients, reporting improvement in all aspects of the Constant Score. We have used Permacol © to reinforce cuff repairs with satisfactory results and thus considered its use as a salvage procedure to bridge massive rotator cuff defects, both of traumatic and degenerate origins. Unfortunately, we have seen with great concern that our results have been less than satisfactory. In a cohort of 20 patients who underwent Permacol © interposition / rotator cuff repair, 4 of these have failed, despite a promising initial recovery phase with good pain relief. We believe that use of this and similar implants to bridge a defect in the cuff is not indicated; MRI and dynamic ultrasound examination showed an inflammatory response in the shoulder, and resulting weakness/failure of the implant. We present clinical, radiographic, and histological findings of our experience and a discussion as to the probable cause for the failure of this implant in this particular group of patients.
Acute lateral dislocation of the patella has been associated with disruption of the medial restraints of the patella. Following non-operative management there is a redislocation rate of up to 44%. This is an observational study testing whether sonography is a reliable method of assessing the medial retinaculum after acute dislocation of the patella. Ten patients following acute patellar dislocation had an ultrasound scan (USS) performed by an experienced musculoskeletal radiologist. Each patient subsequently had an examination under anaesthetic, arthroscopy, and repair of the ruptured structures. The ultrasound reports were compared to the surgical findings to determine the accuracy of this investigation. USS located deficiencies in the ligamentous attachments to the medial border of the patella and the presence of avulsed bony fragments, all of which were confirmed at operation. The sonographic diagnosis of haematoma or torn fibres in the vastus medialis obliquus corresponded with our operative findings. The most significant findings were the correlation of free fluid around the medial collateral ligament (MCL) with avulsion of the femoral attachment of the medial patellofemoral ligament (MPFL) and the presence of avulsed fragments of bone from the medial border of the patella. Sonography, in cadaveric studies consistently identifies the retinacula and like MRI offers a distinctive constellation of findings that can be used in diagnosis and therefore play a significant role in directing surgical management of these patients. We have found Sonography to be readily available and accurate. This report does not include surgical outcome since the follow up is short and incomplete. We do, however, feel that ultrasound shows the state of the soft tissue restraints of the patella following lateral dislocation.
The osseo-integration of an uncemented acetabular component depends on its initial stability. This is usually provided by under-reaming of the acetabulum. We have assessed the fixation of 52 mm porous-coated hemispherical prostheses inserted into cadaveric acetabula under-reamed by 1, 2, 3 and 4 mm. We tested the torsional stability of fixation, after preloading with 686 N in compression, by measuring the torque required to produce 1 degree and 2 degrees of rotation. Under-reaming by 2 mm and 3 mm gave significantly better fixation than 1 mm (p less than 0.01, p less than 0.02). Insertion after under-reaming of 4 mm caused some fractures. To obtain maximum interference fit and optimal implant stability, we recommend the use of an implant 2 mm or 3 mm larger than the last reamer.
Cadaveric experiments in 10 knees were used to study the strength of two methods of internal fixation for a fractured patella. A modified AO tension band technique was compared with the combination of cerclage wiring and a tension band used at Pyrford. The repairs were stressed to failure; the combination of cerclage and tension band wiring proved to be significantly stronger and is recommended.
