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Fulltext The HUKM Spinal Instrumentation System for adolescent idiopathic scoliosis. A biomechanical comparison study using finite element analysis

Azlan AM, Mohammad AR, Ariffin AK

Med J Malaysia, 2005 Jul;60 Suppl C:30-4.
PMID: 16381280 MyJurnal

This finite element analysis is aimed at comparing relative stiffness of three different posterior instrumentation constructs: the Hospital Universiti Kebangsaan Malaysia Spinal Instrumentation System (HUKM-SIS), the Cotrell-Dubousset Instrumentation (CDI) and Harrington Instrumentation System (HIS), used in the treatment of adolescent idiopathic scoliosis (AIS). The constructs were tested under various loads using MSC Patran 2001 r2a. Under increasing flexion loads, there was a linearly corresponding increase in deflection magnitudes for all constructs on the load-deflection curve. The CDI was the stiffest construct under axial, forward flexion and extension loads, followed by the HUKM-SIS and HIS. Under lateral bending loads, the HUKM-SIS construct was the stiffest followed by CDI and HIS. The HUKM-SIS construct was stiffer than HIS under torsional loads. We conclude that multiple pedicle screws increase the stiffness of posterior instrumentation constructs under all loads and inter-segmental spinous processes wiring increase the stiffness against lateral bending.

Matched MeSH terms: Internal Fixators*
Fulltext Closed Intramedullary Locking Nailing for Metacarpal Fractures: A Retrospective Study of Sixty-Six Fractures

Ghazala C, Choudhry N, Rajeev A

Malays Orthop J, 2018 Jul;12(2):7-14.
PMID: 30112122 DOI: 10.5704/MOJ.1807.002

Introduction: Metacarpal fractures are frequent injuries in the young male working population and the majority are treated non-operatively. There is a growing trend to surgically treat these fractures, with the aim of reducing the deformity and shortening the rehabilitation period. The aim of this retrospective case series is to report on our experience and clinical outcomes of using percutaneous flexible locking nails for the management of displaced metacarpal fractures. This study is a retrospective review of 66 fractures that were managed at our centre over a 7-year period. Materials and Methods: Records of 60 patients were retrospectively reviewed. Indications for surgery were a displaced metacarpal shaft or neck fracture with associated rotational deformity, or multiple metacarpal fractures. The fracture was reduced by closed manipulation, and a flexible pre-bent locked intramedullary nail (1.6mm diameter) was inserted through a percutaneous dorsal antegrade approach, facilitated by a specially designed pre-fabricated awl. The implant was removed at union. Patients were followed-up in clinic until the fracture had united. Results: The mean union time was seven weeks (range 2 to 22 weeks) and there were nine (14%) delayed unions (>3 months) and no non-unions. The nail had migrated in three cases (5%) and caused skin impingement in two cases (3%). There was one infected case (2%). Rotational clinical deformity was evident for two (3%) cases. Conclusion: The use of a minimally-invasive locked intramedullary nailing for unstable metacarpal fractures has a significantly low complication rate, with predictable union times and good functional outcomes.

Matched MeSH terms: Internal Fixators
Fulltext Screw osteosynthesis of displaced lateral humeral condyle fractures in children: a mid-term review

Loke WP, Shukur MH, Yeap JK

Med J Malaysia, 2006 Feb;61 Suppl A:40-4.
PMID: 17042228

Displaced humeral condyle fractures in children are traditionally fixed with smooth Kirschner wire at the expense of a risk of secondary displacement following removal of wire. Screw fixation of such fractures has recently been advocated as it provides stable fixation. We have been using screw osteosynthesis for treatment of displaced lateral humeral condyle fractures in children in our institution since the turn of this century. This study provides a midterm review of treatment of such injuries with special regards to growth disturbances after screw osteosynthesis and to assess rate of union with a view to formulate guidelines for screw removal. We review the outcomes of screw osteosynthesis for displaced lateral condyle fracture of the humerus (19 Milch type-1 and 15 Milch type-II) in 34 children treated in our institution from January 2000 to March 2004. The average age of the patients was 6.1 years. The average follow up was 24.5 months. Screw osteosynthesis led to union (average 6.9 weeks) in all patients with excellent results in 28 patients. Growth disturbances in the form of lateral condyle overgrowth (2 patients), valgus deformity secondary to lateral condyle avascular necrosis (2 patients) and fishtail deformity ((3 patients) were recognized. The implants should not be removed until fracture union is established. Screw osteosynthesis of the lateral humeral condyle fracture prevents secondary fracture redisplacement and lateral condyle overgrowth is probably related to hyperemic response to metaphyseal fixation and early removal of implant before radiological union.

Matched MeSH terms: Internal Fixators*
Fulltext Sliding compression screw fixation for delayed union/non-union of femoral neck fracture: is it a viable option

Faisham WI, Sulaiman AR, Zulmni W

Med J Malaysia, 2006 Feb;61 Suppl A:36-9.
PMID: 17042227

Femoral neck fracture non-unions often present with significant difficult treatment decision as regards to surgical options and the risk of complication. We present three cases of femoral neck non-union treated with double screw stabilization technique using sliding compression hip screw and anti-rotational screw. The rationale for opting to these simple implants in our setting is discussed.

Matched MeSH terms: Internal Fixators*
Fulltext Coronal plane and apical vertebral rotation correction of adolescent idiopathic scoliosis with multisegmented hook-rod system--a retrospective review

Kwan MK, Chooi WK, Lim HH

Med J Malaysia, 2004 Dec;59 Suppl F:14-8.
PMID: 15941155

Between April 1998 and December 1999, thirty patients with Idiopathic Scoliosis were operated with Multisegmented Hook-Rod System. These patients were operated at the mean age of 16 years and were followed up for a mean of 22.3 months (range 13-34 months). Seven patients had anterior release to increase the curve flexibility followed by second stage posterior instrumentation on the same day. The average operating time for a posterior instrumentation alone and anterior release combined with posterior instrumentation were 270 minutes and 522 minutes respectively. The average blood loss was 2.2 litres for posterior instrumentation alone and 3.3 litres for single day anterior release and posterior surgery. The mean preoperative Cobb's angle was 70 degrees. The mean immediate postoperative and final follow up Cobb's angles were 38 and 42 degrees, which represented an average coronal plane correction of 46.7% and 40.0% respectively. The mean preoperative apical vertebral rotation was 25 degrees, which improved to 15 degrees after the operation. At final follow up, the mean apical vertebra rotation was 20 degrees, which represented a mean apical vertebral rotation correction of 20%. Complications of the procedure included one transient neurological deficit, one infection, one graft site infection and one case of screw cut out. We were able to obtain satisfactory correction of idiopathic scoliosis with the Multisegmented Hook-Rod System.

Matched MeSH terms: Internal Fixators*
Rod Lengthening With the Magnetically Controlled Growing Rod: Factors Influencing Rod Slippage and Reduced Gains During Distractions

Cheung JPY, Yiu KKL, Samartzis D, Kwan K, Tan BB, Cheung KMC

Spine (Phila Pa 1976), 2018 04 01;43(7):E399-E405.
PMID: 28767632 DOI: 10.1097/BRS.0000000000002358

STUDY DESIGN: Prospective study.
OBJECTIVE: To identify the factors that are associated with rod slippage and to study the pattern of achieved length gain with a standard distraction methodology.
SUMMARY OF BACKGROUND DATA: Ability to achieve successful magnetically controlled growing rod (MCGR) distraction is crucial for gradual spine lengthening. Rod slippage has been described as a failure of internal magnet rotation leading to a slippage and an inability to distract the rod. However, its onset, significance, and risk factors are currently unknown. In addition, how this phenomenon pertains to actual distracted lengths is also unknown.
METHODS: A total of 22 patients with MCGR and at least six distraction episodes were prospectively studied. Patients with rod slippage occurring less than six distraction episodes were considered early rod slippage whereas those with more than six episodes or have yet to slip were grouped as late rod slippage. The association of parameters including body habitus, maturity status, age of implantation, total number of distractions, months of distraction from initial implantation, initial and postoperative Cobb angle, T1-T12, T1-S1, T5-T12 kyphosis, curve flexibility, instrumented length, and distance between magnets in dual rods and between the magnets and apex of the curve with early or late onset of rod slippage were studied. Differences between expected and achieved distraction lengths were assessed with reference to rod slippage episodes and rod exchanges to determine any patterns of diminishing returns.
RESULTS: Patients had mean age of 7.1 years at diagnosis with mean follow-up of 49.8 months. A mean 32.4 distractions were performed per patient. Early rod slippage occurred in 14 patients and late rod slippage occurred in eight patients. Increased height, weight, body mass index, older age, increased T1-12 and T1-S1 lengths, and less distance between magnets were significantly associated with early rod slippage. Expected distraction lengths did not translate to achieve distraction lengths and reduced gains were only observed after achieving one-third of the allowable distracted length in the MCGR. Length gains return to baseline after rod exchange.
CONCLUSION: This is the first study to specifically analyze the impact of rod slippage on distraction lengths and the risk factors associated with its onset and frequency. Increased body habitus and reduced distance between internal magnets significantly influenced rod slippage events. Diminishing returns in distracted length gains were only observed after a period of usage.
LEVEL OF EVIDENCE: 3.

Matched MeSH terms: Internal Fixators*
Breakage of an intramedullary rod after bone union in congenital pseudoarthrosis of the tibia: a report of two cases

Sulaiman AR, Simbak N, Wan Ismail WF, Wan Z, Halim AS

J Orthop Surg (Hong Kong), 2011 Aug;19(2):250-3.
PMID: 21857057

We report 2 patients with congenital pseudoarthrosis of the tibia who underwent intramedullary Rush rod transfixation through the ankle joint following refracture and nonunion of vascularised fibular grafting 6 and 8 months earlier. After 9 and 5 years, both Rush rods were broken at the level of the ankle joints, while the reconstructed area was solidly united. The growth of the distal tibia increased the distance of the tips of the broken rod and hence the ankle joint motion. The broken tips may damage the articular cartilage and result in valgus deformity of the ankle and limb length discrepancy.

Matched MeSH terms: Internal Fixators*
The effect of excision of the posterior arch of C1 on C1/C2 fusion using transarticular screws

Chang KC, Samartzis D, Fuego SM, Dhatt SS, Wong YW, Cheung WY, et al.

Bone Joint J, 2013 Jul;95-B(7):972-6.
PMID: 23814252 DOI: 10.1302/0301-620X.95B7.30598

Transarticular screw fixation with autograft is an established procedure for the surgical treatment of atlantoaxial instability. Removal of the posterior arch of C1 may affect the rate of fusion. This study assessed the rate of atlantoaxial fusion using transarticular screws with or without removal of the posterior arch of C1. We reviewed 30 consecutive patients who underwent atlantoaxial fusion with a minimum follow-up of two years. In 25 patients (group A) the posterior arch of C1 was not excised (group A) and in five it was (group B). Fusion was assessed on static and dynamic radiographs. In selected patients CT imaging was also used to assess fusion and the position of the screws. There were 15 men and 15 women with a mean age of 51.2 years (23 to 77) and a mean follow-up of 7.7 years (2 to 11.6). Stable union with a solid fusion or a stable fibrous union was achieved in 29 patients (97%). In Group A, 20 patients (80%) achieved a solid fusion, four (16%) a stable fibrous union and one (4%) a nonunion. In Group B, stable union was achieved in all patients, three having a solid fusion and two a stable fibrous union. There was no statistically significant difference between the status of fusion in the two groups. Complications were noted in 12 patients (40%); these were mainly related to the screws, and included malpositioning and breakage. The presence of an intact or removed posterior arch of C1 did not affect the rate of fusion in patients with atlantoaxial instability undergoing C1/C2 fusion using transarticular screws and autograft.

Matched MeSH terms: Internal Fixators/adverse effects*
Computerized tomographic measurement of the cervical pedicles diameter in a Malaysian population and the feasibility for transpedicular fixation

Yusof MI, Ming LK, Abdullah MS, Yusof AH

Spine (Phila Pa 1976), 2006 Apr 15;31(8):E221-4.
PMID: 16622365

The cervical pedicle diameter size differs between Asians and non-Asians. The authors studied the transverse pedicle diameter of the C2-C7 of the cervical spine in a Malaysian population using computerized tomography (CT) measurements. The transverse diameter of the pedicle is the determinant of the feasibility of this technique because the sagittal diameter of the pedicle has been wider than the transverse pedicle diameter.

Matched MeSH terms: Internal Fixators
Fulltext Sleeve fracture of the patella in a child

Rasit AH, Sharaf I, Pan KL

Med J Malaysia, 2004 Dec;59 Suppl F:52-3.
PMID: 15941163

Sleeve fracture of the inferior pole of the patella is a rare and distinctive fracture in children with few published reports. These fractures are frequently misdiagnosed and neglected. We highlight a case of a neglected and misdiagnosed sleeve fracture of the patella in an eleven-year-old boy. This was initially diagnosed as an avulsion fracture of the tibial tubercle. A good outcome was achieved after open reduction and internal fixation.

Matched MeSH terms: Internal Fixators
Transplantation of human dental pulp stem cells: enhance bone consolidation in mandibular distraction osteogenesis

Alkaisi A, Ismail AR, Mutum SS, Ahmad ZA, Masudi S, Abd Razak NH

J Oral Maxillofac Surg, 2013 Oct;71(10):1758.e1-13.
PMID: 24040948 DOI: 10.1016/j.joms.2013.05.016

The main aim of the present study was to evaluate the capacity of stem cells from human exfoliated deciduous teeth (SHED) to enhance mandibular distraction osteogenesis (DO) in rabbits.

Matched MeSH terms: Internal Fixators
Congenital pseudoarthrosis of the tibia: healing by lengthening over a rod without compression of the nonunion. A preliminary report

Muhammad Abdul Jamil MK, Abdul Rashid AH, Ibrahim S

J Pediatr Orthop B, 2013 May;22(3):207-12.
PMID: 22182834 DOI: 10.1097/BPB.0b013e32834ecc01

This preliminary report is on two patients with congenital pseudoarthrosis of the tibia who had a persistent nonunion following intramedullary rodding and bone grafting. We do not advocate repeated surgery to achieve union. When limb length discrepancy becomes greater than 5 cm, we proceeded with an Ilizarov procedure with the primary aim of equalizing limb length rather than achieving union. Healing of the pseudoarthrosis occurred in both patients after lengthening over the intramedullary rod without compression of the nonunion site. We believe that union occurs because of hyperaemia during the lengthening. This approach minimizes the repeated surgeries that are usually needed and thus ensures a more normal childhood without frequent hospitalizations.

Matched MeSH terms: Internal Fixators