Archives of orthopaedic and trauma surgery
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Arch Orthop Trauma Surg · Mar 2002
Comparative StudyEffect of continuous versus dichotomous outcome variables on study power when sample sizes of orthopaedic randomized trials are small.
It is often not feasible to conduct large trials in orthopaedic surgery. Therefore, surgeons must identify strategies to optimize the statistical power of their smaller studies. The aim of this study was to compare study power in randomized trials with continuous versus dichotomous outcome variables. ⋯ Studies that reported continuous outcomes had a significantly higher mean power than those that reported dichotomous variables (power 49% vs 38%, p=0.042). Twice as many trials with continuous outcome variables reached acceptable levels of study power (i.e. >80% power) when compared with trials with dichotomous variables (37% vs 18.6%, p=0.04). When orthopaedic surgeons anticipate small sample sizes for their study, they can optimize their study's statistical power by choosing a continuous outcome variable.
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Arch Orthop Trauma Surg · Feb 2002
Comparative StudyComparison of two different posterior approachs for hemiarthroplasty of the hip.
A prospective study was undertaken on 183 patients who had suffered a femoral neck fracture between 1998 and 1999. The aim was to compare the complication rates for the classical posterior approach and the modified posterior approach. The modified posterior approach used was the one described by Williams et al., which preserved the pyriformis, the labrum and the capsule. ⋯ This difference was statistically significant (p < 0.05). There were no significant differences in the incidences of other intraoperative and postoperative complications. We concluded that the modified posterior approach significantly increases the stability of a hemiarthroplasty in relation to the classical posterior approach.
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Arch Orthop Trauma Surg · Feb 2002
Comparative StudyOncologic and functional results after treatment of giant cell tumors of bone.
Surgical treatment of giant cell tumor of bone has always been a difficult problem because of its local aggressive behavior. Oncologic results and functional outcome are reported here in a retrospective study of 36 patients, treated by various surgical procedures. The average age at the time of diagnosis was 34 years, and the median follow-up period was 7 years. ⋯ Wide excision was associated with a poor functional outcome and marginal excision with a good functional outcome. For the treatment of giant cell tumor of bone, intralesional excision with local adjuvant therapy is recommended because of a good functional outcome. When applying cryosurgery as the local adjuvant, more vigorous freezing may be necessary to improve local tumor control.
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Arch Orthop Trauma Surg · Feb 2002
Removal of well-fixed or porous-coated cementless stems in total hip revision arthroplasty.
The removal of well-fixed or porous-coated cementless stems is demanding and associated with a hig perioperative risk to the patient. Only a few surgical techniques have been published about this procedure. We introduce a special, ballistically driven, flexible chisel for the disruption of bone ingrowth or fibrous encapsulation. ⋯ Reimplantation is possible with standard stems for primary surgery. This surgical technique leads to a predictable procedure, reduces the risk for the patient, the operation time and costs. We are continuing with this technique under supervision by the local Ethics Commission.
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Arch Orthop Trauma Surg · Feb 2002
Comparative StudyAdjacent segment degeneration after lumbar spinal posterolateral fusion with instrumentation in elderly patients.
This retrospective study investigated adjacent segments radiologically and clinically after posterolateral fusion of the lumbar spine with instrumentation. Thirty-two patients over 60 years old with a postoperative follow-up of at least 4 years were included. These patients all met the criteria of a postoperative symptom-free period of over 2 years, evident fusion mass seen on plain radiographs, and no implant breakage or loosening. ⋯ However, no statistically significant difference (p = 0.7878) was found according to the Fisher exact test. Comparing the effect of different types of instruments, there still was no statistically significant difference (p = 0.1161) between the VSP plate and Isola rod groups in inducing degeneration of adjacent segments after posterolateral fusion of the lumbar spine. After measuring the mobility of degenerated adjacent segments, relative hypermobility was more likely responsible for the accelerated degeneration rather than the absolute increase of mobility.