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Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 135 - 135
1 Feb 2003
Shannon FJ DiResta G Ottaviano D Castro A Healey JH Boland PJ
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Introduction: Patients with spinal metastases often have patterns of disease requiring both an anterior and posterior surgical decompression and stabilisation. Subtotal spondylectomy and circumferential stabilisation can be safely performed via a single posterior transpedicular approach. Polymethyl-methacrylate bone cement (PMMA) has been widely used in spinal column reconstruction with mixed results. PMMA is a potential means for local drug delivery in the prevention of locally recurrent disease. The biomechanical characteristics of anterior reconstruction using PMMA have not been adequately evaluated.

Purpose: To evaluate the stability of an anterior cement construct following total spondylectomy and to compare this reconstruction against alternative stabilisation techniques.

Methods: Ten fresh-frozen human cadaveric spines (T9-L3) were used. After intact analysis, a total spondylectomy was performed at T12. Three potential reconstruction techniques were tested for their ability to restore stiffness to the specimen: (1) multi-level posterior pedicle screw instrumentation from T10-L2 {MP1} [Depuy Acromed], (2) anterior instrumentation [ATL Z-plate II™, Medtronic, Sofamor Danek Instruments] and rib graft at T11-L1 with multi-level posterior instrumentation from T10-L2 {AMPI}, and (3) anterior cement [Simplex P] and pins construct (T12) with multi-level posterior instrumentation from T10-L2 {CMPI}. Each of the three potential reconstruction techniques was tested on each specimen in random order. Non-destructive testing was performed under load control. The specimen was positioned vertically for axial compression and torsion testing, and horizontal for flexion/extension and lateral bending tests. A customised jig was manufactured for this latter purpose.

Results: Only circumferential stabilisation techniques (AMPI, CMPI) restored stiffness to a level equivalent or higher to that of the intact spine in all loading modes (p< 0.05). CMPI provided more stability to the specimen than AMPI in compression and flexion testing (p< 0.05). Posterior instrumentation alone (MPI) did not restore stiffness to the intact level in compression and flexion testing (p< 0.005).

Conclusions: Circumferential reconstruction using an anterior cement construct provides equal or more stability than the intact spine in all testing modes. Posterior stabilisation alone is an inadequate method of reconstruction following total spondylectomy. PMMA has the advantage over traditional anterior reconstruction techniques in that it can be inserted using a single posterior approach and offers the potential value of local drug delivery.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 99 - 99
1 Feb 2003
Shannon FJ DiResta G Ottaviano D Castro A Healey JH Boland PJ
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To evaluate and compare the stability of an anterior cement construct following total spondylectomy for meta-static disease against alternative stabilization techniques.

After intact analysis of ten cadaveric spines (T9–L3), a T12 spondylectomy was performed. Three reconstruction techniques were tested for their ability to restore stiffness to the specimen using non-destructive tests:

1) multilevel posterior pedicle screw instrumentation (PPSI) from T10–L2 {MPI}, 2) anterior instrumentation from T11–L1 with PPSI {AMPI}, and 3) anterior cement and pins construct (T12) with PPSI {CMPI}.

Circumferential stabilization {AMPI, CMPI} restored stiffness to a level of the intact spine. CMPI provided more stability to the specimen than AMPI. MPI alone did not restore stiffness to the intact level.

Circumferential reconstruction using an anterior cement construct following total spondylectomy is biomechanically superior to posterior stabilisation alone.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 137 - 137
1 Feb 2003
Shannon FJ Thornes B Awan N Burke T
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Introduction: Fractures of the distal radius are amongst the most commonly encountered injuries in orthopaedic trauma. Treatment options include closed manipulation, percutaneous fixing using K wires and external fixation. Restoration of the volar tilt and radial length are proven to have a positive correlation with a good functional outcome.

A randomised prospective study has been performed to compare the effectiveness of percutaneous stabilisation using K wires inserted in the traditional transcortical fashion with K wires inserted using a novel intramedullary spring loaded technique. The treatments were compared for their ability to restore normal anatomy, carpal alignment and function of the hand after unstable fractures of the distal radius.

Patients and Methods: Between October 2001 and February 2002, 46 patients with unstable fractures of the distal radius were entered into the study. There were 37 females and 9 males, mean age of 58 years (range 17–87). Fractures were classified using the AO system. Patients were randomly allocated using closed envelopes into one of two groups. All fractures were reduced, and three 1.6mm K wires were inserted using one of two techniques. Group I (24 pts) had the wires engaged into the opposite cortex and driven down the medullary canal (spring-loaded). All patients were followed up for a minimum of 6 weeks. Radiological and functional evaluation was performed.

Results: Immediate post operative radiographs showed a mean dorsal angle of –3° in Group I (ie 3 degrees volar tilt) and –7.5° in Group II. Restoration of radial length was similar in both groups. By 6 weeks, the mean dorsal angle for Group I was −1.9°, and –10.6° in Group II. The mean loss of radial length was similar in both groups (1.2mm in Group I; 1.3mm in Group II). Functional outcome was assessed using the Wrist Function Score2, and was similar in both groups at 6 weeks. There were 2 early fixation failures, both in Group I, and both class C3 fractures (AO).

Conclusion: ‘Spring loaded’ percutaneous K wiring of distal radius fractures results a significantly superior restoration of volar tilt post operatively and at 6 weeks when compared against the transcortical technique. The ‘spring’ translates into a dynamic force reducing the fracture. We estimate that these radiological results will result in a superior functional outcome in the longer term.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 138 - 138
1 Feb 2003
Shannon FJ Langhi S Mohan P Chacko J D’Souza L
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Introduction: The preferred treatment for displaced supracondylar humeral fractures in children is closed reduction and percutaneous pinning. Cross-wiring techniques are biomechanically superior to parallel lateral wiring techniques. The purpose of this study was to review our experience with a novel cross wiring technique performed entirely from the lateral side. This avoids the potential for ulnar nerve injury in these difficult cases.

Patients and Methods: We collected all children with supracondylar fractures of the distal humerus who were manipulated and wired by one surgeon, using a lateral cross wiring technique. Patient demographics, mechanism of injury, fracture classification (Gartland’s classification) and associated neurovascular injuries were noted. At follow-up (12 weeks), range of motion and carrying angle were measured.

Results: Twenty patients were identified and reviewed. There were 8 female and 14 male patients, mean age 10 years (range 2–11). Two fractures were Type II, 12 were Type IIIA and 6 were Type IIIB. Three patients had signs of an anterior interosseous nerve injury and one patient had a brachial artery laceration.

All fractures were reduced, cross-wired from the lateral side, and rested in an above elbow slab. Wires were removed at 4 weeks.

At follow-up, all children had a full range of motion and the mean carrying angle was 17° (range: 15–20). All three patients with pre-operative nerve injuries had full recovery of nerve function.

Conclusions: Lateral cross wiring of supracondylar fractures represents a real option in the treatment of these injuries. It offers the biomechanical advantages of traditional cross-wiring without the risk of nerve injury.