A. van Kampen

Rotational malalignment after intramedullary nailing of femoral fractures.

Objectives: Intramedullary nailing has been accepted as the treatment of choice for femoral shaft fractures. The aim of our study was to determine the incidence and implications of rotational malalignment after intramedullary nailing using computed tomography measurements. Design: Cohort study. Setting: Patients who postoperatively visited the orthopaedic outpatient and radiology clinics. Patients: Seventy-six patients, 59 men and 17 women, with a mean age of 28.4 years (15–88). Intervention: Patients treated on a fracture table with an antegrade reamed AO nail (n = 46) or Grosse Kempf nail (n = 30) for a unilateral femoral shaft fracture between 1988 and 1998 were included in the study. Main Outcome Measurements: Patients filled out a questionnaire concerning pain, daily activities, and sport. Oxford, Western Ontario and McMaster University osteoarthritis index, and Harris Hip and Knee Society scores were obtained. Physical exams and computed tomography measurements were established. Results: Twenty-one patients (28%) were found to have a rotational malalignment of 15° or more. There was no significant difference in rotational deformity with either the AO or Grosse Kempf nail. The incidence of malrotation was independent of the fracture level. Patients with a torsional deformity had difficulties with more demanding activities like running, sports, and climbing stairs. Patients with an external rotational malalignment (n = 12) have more functional problems than patients with an internal rotational malalignment (n = 9). Clinically determined rotation differences are not accurate (±20°) compared with the established computed tomography measurements. Conclusions: Rotational malalignment after intramedullary nailing for femoral fractures is found in 28% of the patients in this study. These patients have difficulties with more demanding activities, especially when they have an external torsional deformity.

Avoiding rotational malalignment after fractures of the femur by using the profile of the lesser trochanter: an in vitro study

IntroductionIntramedullary (IM) nailing has become the preferred method of treatment for femoral shaft fractures in adults. Rotational malalignment is an important complication, established during operation. The incidence of rotational malalignment (≥15°) has been reported to be between 20% and 30%. It might be avoided intra-operatively by using quantitative imaging techniques, with the profile of the contralateral lesser trochanter serving as a reference.Materials and methodsWith the help of a C-arm image intensifier, five surgeons tried to determine the neutral state of ten prepared cadaver femora. They could only look at the C-arm screen and were blinded to the actual femur. Per observer three measurements were done per femur. The first measurement (method I) was done without a reference, while the second (method II) used a reference image of the femur in a neutral state. The third method (method III) added a lesser trochanter quantifying computer program. After positioning of the femur, the difference in rotational state compared with the neutral state was measured with an inclinometer.ResultsWithout reference, malrotations up to 27° were found. Methods II and III proved to be significantly better (p<0.0001). These two methods showed malrotation of 2.2° (±1.5°) and 2.3° (±1.7°), respectively. External or internal malrotation occurred with all three methods equally frequently. No difference was found between observers.ConclusionsUsing the contralateral lesser trochanter as a reference is an accurate method to minimize malrotation of a femur. Quantifying the profile of the lesser trochanter with computer assistance did not improve these results. Clinical results in the future still have to support these in vitro findings.

An unstable pelvic ring : The killing fracture

An unstable pelvic fracture may be life threatening and can be seen as ‘the killing’ fracture. Even if this is the only injury, it may be a serious problem. In the initial management of this type of fracture, the principles of advanced trauma life support (ATLS)[1][1] must be observed, with

ACL graft can replicate the normal ligament's tension curve.

The anatomical femoral insertion of the normal anterior cruciate ligament (ACL) lies on the deep portion of the lateral wall of the intercondylar fossa. Following the deep bone–cartilage border, it stretches from 11 o’clock high in the notch all the way down to its lowest border at 8 o’clock. The tension curve of the normal ACL during passive flexion–extension shows a characteristic pattern with two tension peaks, one in full extension and the other in deep flexion. Low tension in mid-flexion is measured between those two peaks. Standard ACL reconstructions use a femoral insertion at 11 o’clock, which results in non-physiological tension curves with one peak in full extension only. The hypothesis was that it is possible to reproduce the typical tension curve of the normal ACL by placing the femoral tunnel into the low part of the normal ACL footprint. In a controlled laboratory study, three different femoral tunnel positions at 9, 10 and 11 o’clock were tested in four cadaver knees while using the identical standard tibial tunnel each time. The tension curve was measured during passive flexion–extension with a custom-made tension measurement device, using an artificial Dacron graft. The tension curve of grafts in the 9 o’clock tunnels showed the characteristic pattern of the normal ACL’s tension curve with tension peaks in extension as well as in deep flexion. The tunnels in the 10 and 11 o’clock positions failed to reproduce the normal ACL’s tension curve with high-tension values in extension only. Clinical relevance: If an ACL graft is placed low within the normal femoral footprint, the physiological tension curve of the normal ACL can be reproduced.

Human syndromes with congenital patellar anomalies and the underlying gene defects

Genetic disorders characterized by congenital patellar aplasia or hypoplasia belong to a clinically diverse and genetically heterogeneous group of lower limb malformations. Patella development involves different molecular and cellular mechanisms regulating dorso‐ventral patterning, cartilage and bone formation along endochondral ossification pathways, and growth. Several human genes that are important for patella development have been uncovered by the study of human limb malformation syndromes, yet causative genes for many more such disorders await to be identified and their complex interactions in the developmental pathways deciphered. Mutant animal models of congenital patellar aplasia or hypoplasia are certainly instrumental to create more insight into this aspect of limb development. Moreover, investigation of the complete phenotype of human syndromes and animal models may reveal novel insights into the pleiotropic roles of the responsible genes in the normal developmental of other organ systems. In this review, the phenotype and gene defects of syndromes with congenital patellar aplasia or hypoplasia will be discussed, including the nail patella syndrome, small patella syndrome, isolated patella aplasia hypoplasia, Meier–Gorlin syndrome, RAPADILINO syndrome, and genitopatellar syndrome.

A randomised, controlled trial of circumpatellar electrocautery in total knee replacement without patellar resurfacing

The efficacy of circumpatellar electrocautery in reducing the incidence of post-operative anterior knee pain is unknown. We conducted a single-centre, outcome-assessor and patient-blinded, parallel-group, randomised, controlled trial to compare circumpatellar electrocautery with no electrocautery in total knee replacement in the absence of patellar resurfacing. Patients requiring knee replacement for primary osteoarthritis were randomly assigned circumpatellar electrocautery (intervention group) or no electrocautery (control group). The primary outcome measure was the incidence of anterior knee pain. A secondary measure was the standardised clinical and patient-reported outcomes determined by the American Knee Society scores and the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index. A total of 131 knees received circumpatellar electrocautery and 131 had no electrocautery. The overall incidence of anterior knee pain at follow-up at one year was 26% (20% to 31%), with 19% (12% to 26%) in the intervention group and 32% (24% to 40%) in the control group (p = 0.02). The relative risk reduction from electrocautery was 40% (9% to 61%) and the number needed to treat was 7.7 (4.3 to 41.4). The intervention group had a better mean total WOMAC score at follow-up at one year compared with the control group (16.3 (0 to 77.7) versus 21.6 (0 to 76.7), p = 0.04). The mean post-operative American Knee Society knee scores and function scores were similar in the intervention and control groups (knee score: 92.4 (55 to 100) versus 90.4 (51 to 100), respectively (p = 0.14); function score: 86.5 (15 to 100) versus 84.5 (30 to 100), respectively (p = 0.49)). Our study suggests that in the absence of patellar resurfacing electrocautery around the margin of the patella improves the outcome of total knee replacement.

Bone impaction grafting and a cemented cup after acetabular fracture at 3-18 years.

The outcome of total hip arthroplasty after acetabular fracture is compromised. We studied if the bone impaction grafting technique could provide long-term prosthesis survival in deformed and irregular acetabula. We studied 20 hips in 20 patients (mean age, 53.3 years; range, 35-75 years) that were reconstructed with acetabular bone impaction grafting and a cemented total hip prosthesis after acetabular fracture. No patient was lost to followup. At review the mean followup was 9.5 years (range, 3-18 years) and the average Harris hip score was 93 (range, 62-100). During followup there were two cup revisions: one after 14.5 years for septic loosening, and one after 15.3 years for aseptic loosening. The Kaplan-Meier survival rate of the cup with end-point revision for any reason was 100% at 10 years and 80% (95% CI; range, 62-98%) after 15 years. With end-point cup revision for aseptic loosening the survival rate was 100% at 10 years. Acetabular bone impaction grafting with a cemented cup is a biologically attractive technique with good long-term survival used to reconstruct bone stock loss after posttraumatic arthritis. The complication and reoperation rate was low in this relatively young group of patients. Level of Evidence: Therapeutic study, Level IV (Case series-no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.

Structural biomarkers in the cerebrospinal fluid within 24 h after a traumatic spinal cord injury: a descriptive analysis of 16 subjects

Study design:Prospective cohort study.Objectives:To characterize the cerebrospinal fluid (CSF) concentrations of glial fibrillary acidic protein, neuron specific enolase (NSE), S-100β, tau and neurofilament heavy chain (NFH) within 24 h of an acute traumatic spinal cord injury (SCI), and to correlate these concentrations with the baseline severity of neurologic impairment as graded by the American Spinal Injury Association impairment scale (AIS).Methods:A lumbar puncture was performed to obtain CSF from 16 acute traumatic SCI patients within 24 h post injury. Neurological examinations were performed within 24 h of injury and again at 6 or 12 months post injury. The correlations between the CSF concentrations and initial AIS were calculated by using Pearson correlation coefficients. In addition, an independent Student’s t-test was used to test for differences in CSF concentrations between patients of different AIS grades.Results:The CSF NSE concentrations were significantly correlated with the baseline neurologic impairment being either ‘motor complete’ (AIS A, B) or ‘motor incomplete’ (AIS C, D) (r=0.520, P<0.05). The mean S-100β concentration in motor complete patients was significantly higher compared with motor incomplete patients; 377.2 μg l−1 (s.d.±523 μg l−1) vs 57.1 μg l−1 (s.d.±56 μg l−1) (P<0.05), respectively. Lastly, the mean NFH concentration in motor complete patients was significantly higher compared with motor incomplete patient, 11 813 ng l−1 (s.d.±16 195 ng l−1) vs 1446.8 ng l−1 (s.d.±1533 ng l−1), (P<0.05), respectively.Conclusion:In this study we identified differences in the structural CSF biomarkers NSE, S-100β and NFH between motor complete and motor incomplete SCI patients. Our data showed no clear differences in any of the protein concentrations between the different AIS grades.

Femoral neck shortening after internal fixation of a femoral neck fracture.

This study assesses femoral neck shortening and its effect on gait pattern and muscle strength in patients with femoral neck fractures treated with internal fixation. Seventy-six patients from a multicenter randomized controlled trial participated. Patient characteristics and Short Form 12 and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were collected. Femoral neck shortening, gait parameters, and maximum isometric forces of the hip muscles were measured and differences between the fractured and contralateral leg were calculated. Variables of patients with little or no shortening, moderate shortening, and severe shortening were compared using univariate and multivariate analyses. Median femoral neck shortening was 1.1 cm. Subtle changes in gait pattern, reduced gait velocity, and reduced abductor muscle strength were observed. Age, weight, and Pauwels classification were risk factors for femoral neck shortening. Femoral neck shortening decreased gait velocity and seemed to impair gait symmetry and physical functioning. In conclusion, internal fixation of femoral neck fractures results in permanent physical limitations. The relatively young and healthy patients in our study seem capable of compensating. Attention should be paid to femoral neck shortening and proper correction with a heel lift, as inadequate correction may cause physical complaints and influence outcome.

Computed tomography determined femoral torsion is not accurate

IntroductionComputed tomography (CT) is considered the method of choice for detecting rotational malalignment of the femur. However, it is unclear how reliable the method is, and what the causes are of potential inaccuracies.Materials and methodsTo address these issues three observers measured the CT images of the femur of 76 patients on two separate occasions. The images were made during follow-up of a unilateral femoral shaft fractures. Rotational malalignment was determined by comparing the torsion angle of the injured to the noninjured leg.ResultsThe pooled intraobserver variance was 3.9° and interobserver variance 4.1°. Of the two measurements of one observer 95% were up to 10.8° different, and between observers 95% of the measurements were up to 15.6° different.ConclusionsCT measurements of rotational malalignment of the femur are not accurate. This is due principally to the difficulty in defining a line through the axis of the femoral neck. The accuracy can be improved by taking the average of two measurements.