Correlation between goniometric and photogrammetric assessment of shank-forefoot alignment in athletes

BACKGROUND

The shank-forefoot alignment (SFA) measurement has been previously developed to enhance the applicability of foot alignment measurement in sports preseason assessment because it is reliable and less time consuming. The use of SFA measurements in the clinical context, usually done with photogrammetry, may be simplified by using the universal goniometer and no longer requiring the image processing step that takes additional time and equipment.

OBJECTIVE

Investigate the correlation between the goniometric and photogrammetric assessment of shank-forefoot alignment in athletes.

PARTICIPANTS

Thirty volleyball athletes were recruited during a preseason assessment.

METHODS

SFA measurements were assessed with a universal goniometer and photogrammetry. For both assessments the participants were positioned in prone with the rearfoot facing up and the ankle actively maintained in 90° of dorsiflexion. The examiner did not have access to the SFA outcome values from both measurements. A second examiner did the bi-dimensional analysis with SIMI MOTION (photogrammetric measure) and read the goniometer measures during the other SFA assessment. Data normality was tested using Shapiro-Wilk test and Pearson was used to determine the correlation between both measurements.

RESULTS

A reliability study determined the Intraclass Correlation Coefficient (ICC3,3) for intra-rater reliability of 0.93 for photogrammetry and of 0.81 for goniometry assessment. The correlation (p < 0.001) between these two measurements was 0.71, which indicates a moderate relationship.

CONCLUSIONS

This study describes a reliable and practical measurement procedure for shank-forefoot alignment using the universal goniometer that can be easily applied in clinical context.

Clinical and radiological outcomes of high tibial osteotomy with combined fixator-assisted nailing and subtubercle tibial osteotomy

OBJECTIVE

The aim of this study was to assess the clinical and radiological results of our high tibial osteotomy technique combining fixator-assisted nailing and subtubercle tibial osteotomy in varus malalignment.

METHODS

This was a retrospective study of a consecutive series of 32 knees in 32 patients ('2 follow-up loss' 12 males and 18 females; mean age at the time of operation: 50.6±7.8 (36-62) years) operated on between 2014 and 2016. Radiographic and clinical measurements were assessed pre- and postoperatively. Kolmogorov-Smirnov, paired t and Wilcoxon rank tests were used in the statistical analyses.

RESULTS

The mean follow-up period was 36.1±8.15 (31-53) months, the mean duration of the hospital stay was 3.6±0.1 (2-6) days, and the mean Kellgren-Lawrence score was 2.4±0.6 (2-4). Time to bony union was an average of 16.17 (12-29) weeks. Compared to the preoperative mechanical medial proximal tibial angle, femorotibial angle and mechanical axis deviation measurements, all the postoperative values showed significant changes (p<0.01). However, there was no statistical difference between the preoperative and postoperative tibial slopes (p>0.05), and the postoperative Caton-Deschamps index did not show a meaningful change (p>0.05). The postoperative visual analog scale, Knee Society Score, and Modified Hospital for Special Surgery Knee Scoring System measures showed significant improvement compared to the preoperative values (p<0.01). The postoperative walking distance increased to 1137.50±845.1 meters, from 359.4±306.2 meters (p<0.01).

CONCLUSION

This percutaneous technique is minimally invasive, corrects the alignment in two planes, and does not affect patellar height. We believe that this technique could be a promising alternative to other knee preserving surgeries in correcting varus malalignment.

LEVEL OF EVIDENCE

Level IV, Therapeutic Study.

[Extracapsular Proximal Femoral Fractures - Retrospective Evaluation of a Group of Patients with a Focus on Complications of Treatment]

PURPOSE OF THE STUDY The purpose of this study is to retrospectively evaluate the treatment and the complications in patients with extracapsular proximal femoral fractures. MATERIAL AND METHODS The evaluation focused on a group of patients who underwent a surgery at the authors department in the period from 1 January 2011 to 31 December 2013. The inclusion criteria were a simple fall and a monotrauma. The injury-to-surgery interval, course of the surgery and hospital stay, occurrence of early and late complications were assessed. RESULTS In the respective period 286 patients underwent surgery, with the mean age of 79 years (36-101). A basicervical fracture was suffered by 20 patients, a pertrochanteric fracture by 228 patients and 38 patients sustained a subtrochanteric fracture. Osteosynthesis using the DHS was applied in 113 patients, in 110 patients PFNA osteosynthesis was performed and in 51 patients osteosynthesis using an Ender nail was conducted. Yet another type of plate osteosynthesis was opted for in 12 patients. The most frequent postoperative complication was delirium, which was reported in a total of 38 patients. Non-infectious early seroma and hematoma type collection was observed in 6 patients. An infection occurred in one patient. Apart from 8 patients who died during the primary hospital stay, the fracture healing was followed up in 252 patients (91% of 278). The length of healing was 15 weeks on average, delayed healing was reported in five patients. Primary malposition was seen in 9 patients (3%) and secondary malposition occurred in five patients (2%). There were five cases of non-union (2% of 278) in our group of patients. In the followed-up period, a total of 86 patients (30 % of 286) died within one year after the injury. In cases of death, the follow-up was 100% thanks to the data obtained from the Institute of Health Information and Statistics of the Czech Republic (UZIS). Death as a direct consequence of proximal femur fracture occurred in 66 patients (23% of 286). DISCUSSION The results of complications in our group (infection, delayed healing, malposition and non-union) are comparable to those identified by other authors, with the exception of one-year lethality, which is lower in the presented group. CONCLUSIONS The occurrence of complications after proximal femur surgeries is affected by multiple factors. The most important are the choice of a suitable implant, technically correct execution of osteosynthesis and intensive postoperative treatment, including the continuity of care after hospital discharge. Key words:extracapsular proximal femoral fractures, complications.

Point-of-Care Ultrasonography to Assist in the Diagnosis and Management of Subluxation of the Radial Head in Pediatric Patients: A Case Series

BACKGROUND

A subluxation of the radial head (SRH) is a clinical condition that commonly occurs in children under 6 years of age. History and physical examination findings typically include a child who presents with an elbow held in extension and with forearm pronation, after having suffered significant longitudinal traction on the arm, or after a fall on an outstretched hand. The diagnosis is often clinically obvious. The injury responds dramatically to closed reduction, and usually no imaging is required. However, cases with atypical presentations and patients who do not respond favorably to a reduction maneuver present clinical challenges, because the initial diagnosis of SRH may seem to be questionable or erroneous. Point-of-care ultrasound (POCUS) can assist decision-making and clinical management for these patients.

CASE REPORTS

We report three cases of SRH that were diagnosed and managed with POCUS in the emergency department. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: POCUS can assist in the diagnosis and management of patients with clinical suspicion of SRH, especially in cases of atypical presentations or cases in which the mechanism of injury is unknown. It is also an extremely valuable tool in determining postprocedure reduction success.

Assessment of pisotriquetral misalignment with magnetic resonance imaging: Is it associated with trauma?

OBJECTIVE

Our objective was to determine whether there is an association between pisotriquetral (PT) malalignment and acute distal radius fracture by using magnetic resonance imaging (MRI).

METHODS

We evaluated 138 patients who underwent 3-T MRI of the wrists. Group A comprised 85 patients with acute distal radius fracture, and group B comprised 53 patients without trauma. PT interval and angle and pisiform excursion were measured on oblique axial and sagittal multiplanar reformats. The presence of abnormalities in the flexor carpi ulnaris tendon (FCU), pisometacarpal ligament (PML), and pisohamate ligament (PHL) were evaluated.

RESULTS

PT interval was wider in group A on both the axial and sagittal planes (P < 0.001). Axial PT angle opened more radially in group A (P < 0.001), and the absolute value of the sagittal PT angle in group A was wider than that in group B (P = 0.006). Abnormalities in FCU, PML, and PHL were more frequently observed in group A (P < 0.001). On multiple linear regression, distal radius fracture remained significant after adjusting for the patient's age and PT osteoarthritis.

CONCLUSIONS

Acute distal radius fracture can affect normal alignment of the PT joint, resulting in associated injuries to the primary PT joint stabilizers.

KEY POINTS

• Acute distal radius fracture is associated with malalignment of PT joints. • Acute distal radius fracture is associated with abnormalities of PT stabilizers. • PT joint alignment can be evaluated with MRI with 3D sequences. • Wrist MRI is useful for evaluating primary PT stabilizer injuries.

[Evaluation and analysis of the tibial coronal alignment after total knee replacement with the extramedullary tibial cutting guided by the tibial tubercle and anterior tibial tendon in Chinese patients]

OBJECTIVE

To evaluate the efficiency of the tibial coronal alignment after total knee arthroplasty with the extramedullary cutting system guided by the tibial tubercle and anterior tibial tendon, and to discuss the potential risk factors for the postoperative malalignment.

METHODS

A retrospective study of 212 primary unilateral TKA surgeries (in 188 patients) in our hospital between June to December in 2014 had been analysed. All the cases were performed by one surgical group. An extramedullary tibial cutting guide system had been used, with a landmark of one third inner-medial tibial tubercle as a proximal anatomy reference, and anterior tibial tendon as a distal marker. The mechanical axis of lower extremity in full-length X-ray was measured before surgery, and the tibial prosthetic coronal alignment was checked two weeks postoperation, evaluating the accuracy of this extramedullary cutting system guided by our method.

RESULTS

Since good alignment was defined as an angle within 3 degrees of the perpendicular to the mechanical axis, the tibial component positions were acceptable in 191 knees (90.1%), five knees were in valgus postoperative, and sixteen knees were in varus. There were seventeen(8.7%) in 179 knees with a preoperative varus presented malalignment after surgery, and four in 12 preoperative valgus kneess howed malalignment also, no statistical difference was found by Chi-square test(χ(2)=2.778,P=0.096), which cannot define the relationship between the varus or valgus deformity preoperation and the malalignmentposition in tibial prosthesis after surgery. Twenty-two knees suffered a severe preoperative deformity as a varus or valgus angle larger than 20 degrees with absolute value of mechanical axis before surgery and tibial prosthetic coronal alignment were 21.95 °(20.00°,26.90°)and 1.85°(0.10°, 7.10°), showed a significant difference (Z=2.11,P=0.035) compared with the data [10.65°(0.50°,19.80°)in preoperative mechanical axis and 1.10°(0.00°,4.60°)in the tibial prosthetic coronal alignment]of 190 knees who presented a mild deformity before surgery(less than 20 degrees), the result indicated the severe preoperative deformity might be a potential mal-alignment risk factor within this cutting system in TKA surgery.

CONCLUSION

The tibial coronal alignment after total knee arthroplasty could achieve good results with extramedullary cutting guide, by using one third inner-medial tibial tubercle and anterior tibial tendon as a proximal and distal anatomy marker. Postoperative varus might occur in this system, and tibial prosthetic malalignment appeared more often in the patients who suffered a severe deformity before surgery.

Assessment of in vivo loading history of the patellofemoral joint: a study combining patellar position, tilt, alignment and bone SPECT/CT

PURPOSE

The current study investigates whether patella height and tilt or leg alignment influence the intensity values as well as the distribution pattern of single photon emission computerized tomography/computerized tomography (SPECT/CT) tracer uptake in the patellofemoral joint.

METHODS

99mTc-HDP-SPECT/CT and radiographs of consecutive 84 knees were prospectively obtained. Lateral radiographs were analyzed in terms of patellar height, Insall-Salvati index and modified Insall-Salvati index. Skyline views were analyzed for Laurin's lateral patellofemoral angle. On long-leg radiographs, the mechanical leg alignment was classified as varus, valgus or neutral. SPECT/CT was analyzed for each anatomical region using a previously validated SPECT/CT localization and grading algorithm. Mean, standard deviation, minimum and maximum of grading for each area of the localization scheme were recorded. Nonparametric Spearman's correlations were used to correlate patellar height, lateral patellar angle and leg alignment with the tracer uptake intensity. Chi-square statistics were used for categorical data (p < 0.05).

RESULTS

A patella baja correlated significantly with higher SPECT/CT tracer uptake in all patellar and lateral femoral regions (p < 0.001). A higher lateral patellar tilt correlated significantly with higher tracer uptake in the superior lateral femoral parts and the tibial tubercle. In mechanically varus aligned knees, there was significantly higher SPECT/CT tracer uptake on the medial and in valgus knees on the lateral part of the patellofemoral joint (p < 0.05).

CONCLUSIONS

As the intensity and distribution of the SPECT/CT significantly correlated with patella baja and patellar tilt, SPECT/CT might be considered as imaging modality for evaluating patients with patellofemoral disorders and for follow-up of patients after patellofemoral realignment procedures.

LEVEL OF EVIDENCE

Diagnostic study, Level II.

Timely diagnosis of malalignment of the distal extremities is crucial in morbidly obese juveniles

BACKGROUND/AIMS

To determine i) whether obesity in childhood can be related to malalignment of the distal extremities, ii) the proportion of genu valgum malalignment and abduction setting, and iii) the respective deviation dominance in children who are morbidly obese.

METHODS

31 morbidly obese Caucasian children (16 males) recruited for the STYJOBS Study (ClinicalTrials.gov Identifier NCT00482924) with a mean age of 13.9 ± 0.5 years, a mean height of 162.3 ± 2.7 cm, a mean weight of 90.62 ± 5.0 kg, and a mean BMI of 33.8 ± 1.2 kg/m(2) were clinically examined using the Mikulicz line in order to assess load distribution on the knee joint. 21 participants received a whole-leg X-ray because of a clinically estimated malalignment.

RESULTS

8/31 participants examined were diagnosed with genu valgum, 1/31 with genu varum, and 22/31 did not have any malalignment of the femur or tibia. The majority of genu valgum presentation was due to femoral deviation. Of those without malalignment, 4/22 participants had an abduction setting, while 2/22 showed an adduction of the leg.

CONCLUSION

Genu valgum as a predominant malalignment of the distal extremities is frequent in youth with morbid obesity. Timely guided correction of angular deformity of the knee seems pivotal in order to avoid osteotomy or osteoarthritis later in life.

[A woman with a painful elbow]

A 24-year-old woman with Ehlers-Danlos syndrome visited the emergency department because of a post-traumatic painful and swollen left elbow with impaired function. A plain radiograph showed chronic luxation of the radial head with impression in the humeral capitellum. The clinical presentation of chronic luxation of the radial head is easily confused with that of an acute dislocation of the radial head, which may wrongly result in subsequent reduction.

Correlation between clinical tibiofemoral angle and body mass index in normal Nigerian children

PURPOSE

The tibiofemoral angle (TFA) is a reliable tool for determining lower-limb axial alignment and defining the degree of deformity in pathologic angular malalignment of the knee in children.

METHODS

We clinically examined 471 normal Nigerian elementary school children whose ages ranged from three to ten years to determine the clinical tibiofemoral angle and to establish its relationship with body mass index (BMI).

RESULTS

We found maximum knee valgus of 7.87° at three years, decreasing to 1° at ten years. We also found significant negative correlation between the tibiofemoral angle and BMI. All children examined had weights between the 5th and 85th percentile for age and sex.

CONCLUSION

We conclude that in normal healthy-weight children, BMI does not cause an increase in tibiofemoral angle.

Contemporary femoral designs in total knee arthroplasty: effects on the patello-femoral congruence

PURPOSE

The objective of this study was to evaluate the radiological and clinical correlations between implant design and patellar positioning in patients who underwent TKA utilizing femoral implants with modern designs.

METHODS

Thirty consecutive PFC PS Sigma TKAs, characterized by a new prolonged anterior flange and a "smoother" trochlea, were prospectively reviewed. All patellae were replaced. All patients were evaluated pre-operatively and prospectively at two years follow-up both clinically according to the Knee Society score as well as radiographically. This included computed tomography (CT); patellar tilt, patellar conformity angle, patellar lateralization, and femoral component external-rotation in relation to the clinical trans-epicondylar axis.

RESULTS

Average patellar tilt at follow-up was 3° (±7.5°) with respect to a pre-operative 18.5° (±8.5°). Average patellar congruence angle at follow-up was -3° (range, -11° to +9°) with respect to a pre-operative 10.3° (range, + 1.5° to 25.5°). Average lateralization index at follow-up was 2.7 mm (range, -3.4 mm to +7.1 mm) with respect to a pre-operative 12.2 mm (± 4.8 mm). Femoral component positioning related to the trans-epicondylar axis showed an external rotation of 2.80° (± 2.10°) at follow-up with respect to 5.7° (± 1.80°). Clinically, two (6.6%) patients reported patello-femoral complications related to imperfections in the surgical technique more than the implant's design.

CONCLUSIONS

This study highlighted that modern femoral designs in TKA allow for a correct reproducibility of a normal patello-femoral conformity. Strict surgical principles are paramount to avoid patello-femoral complications even when modern implants are used.

"Grand piano sign," a marker for proper femoral component rotation during total knee arthroplasty

A malpositioned femoral component is an established risk factor for patellar instability and pain after total knee arthroplasty (TKA). In the assessment of femoral rotation, several axes, including the transepicondylar axis, the posterior condylar axis, and the anteroposterior axis, are useful. However, these axes are not always easily applicable, particularly when significant deformity exists. An anecdotal method used by some surgeons involves assessing the shape of the anterior femoral surface osteotomy. Our observations from saw bone models and TKA led to our hypothesis that proper femoral component placement is indicated by a bimodal peak on the anterior femur, approximately twice as high on the lateral side than on the medial side. We use the term "grand piano sign" to describe the shape of the trochlea after the osteotomy is correctly completed. To our knowledge, this common observation has not been studied either in the laboratory or in vivo. Our cadaveric models demonstrated that the grand piano sign correlated with proper femoral rotation during TKA. Surgeons who are knowledgeable about this marker should find it helpful when orienting components during knee replacement surgery.

Impingement as a mechanism of dissociation of a metasul metal-on-metal liner

This case report is of a patient with disassociation of the acetabular cup liner caused by impingement. The cup inclination (39 degrees) and anteversion (24 degrees) were good as measured by computer navigation. Impingement occurred because the head-neck ratio was 2.0, and the hip length and offset were short by one head length. Successful revision without intraoperative impingement was accomplished with one size head larger (32 mm; head-neck ratio, 2.3) and one size longer to correct hip length and offset.

Bilateral pes valgus in an Anatolian Sheepdog

A 15-month-old, male, Anatolian Sheepdog weighing 45 kg, was admitted with uneven stance in both hindlegs, a condition it had had since the age of six months. Radiographs of both hindlimbs revealed lateral deviation of 26 degrees in the distal metaphysis of the left tibia and 32 degrees in the distal metaphysis of the right tibia. Corrective osteotomy was used to treat the deformity. Both tibias were aligned with the closed wedge osteotomy and a suitably curved plate was placed on both bones. In the assessment prior to the removal of both plates, it was determined that a valgus deformation of 6 degrees was still present. However, this did not affect the gait, nor did it have an abnormal effect on the cosmetic appearance. It was concluded that if corrective osteotomy is performed before any degenerative changes have taken place, the outcome will be successful.

[Clinical picture and diagnosis of knee osteoarthritis]

The principal symptom of osteoarthritis of the knee is pain. As the disease progresses, attack-like symptoms with knee pain, effusion, activated osteoarthritis, increasing restriction in knee mobility and reduced walking range occur more frequently. Secondarily joint malalignments also develop. Activities such as climbing stairs or sitting for long periods with bent legs are named as sources of pain for patients with patellofemoral osteoarthritis. Medial and/or lateral osteoarthritis of the knee is very probable when the pain is described as being more lateral or medial. The standard x-ray should always be taken AP and from the side. Axial images of the patella and tangential images of the patellofemoral joint are also made for assessing the centring of the patella and for evaluating retropatellar osteoarthritis. For planning the therapy, x-rays of the knee joint AP while standing or of the entire leg while standing are essential.

Rotational alignment of the finger nails in a normal population

We measured the alignment of the nails in the hands of 100 normal adults with the interphalangeal joints extended and the metacarpophalangeal (MCP) joints at 0 degrees and 90 degrees. All fingers were naturally supinated (i.e. rotated towards the thumb), the index and little being the most supinated. When examining individual hands in MCP joint extension, only 17% of hands had all nails parallel. With the MCP joints flexed, this improved to 56%. If the little finger was excluded, this improved to 78%. When comparing matching fingers from the two hands, 76% of little, 83% of ring, 77% of middle and 80% of index fingers matched. Thumbnails were assessed in extension and found to match the other side in 95% of individuals. This study identifies that examination of the injured hand alone with all joints extended is an unreliable method of assessing malrotation following fracture, especially in the little finger. Comparing matching fingers in the two hands is more reliable, but there is still substantial variation in approximately 20% of normal individuals.

Prevalence of bowlegs among child and adolescent soccer players

OBJECTIVE

Little is known about the interactions of sports-related demands and human body, in particular on musculoskeletal features, during growth. Focusing on the relationship between soccer and lower limb alignment, we examined the hypothesis that varus knee deviation is more prevalent among high-performance pediatric and adolescent soccer players.

DESIGN

Cross-sectional study with focused sampling.

SETTING

First league sports clubs.

PARTICIPANTS

106 male child/adolescent soccer players aged 10 to 21 years and 68 age-matched tennis players.

INTERVENTIONS

All athletes completed a demographic questionnaire and underwent physical examinations, which included height, weight, generalized laxity, knee, ankle, foot and spine axis, hip range of motion, tibial torsion, Q angle, foot navicular height, and progression angle.

MAIN OUTCOME MEASUREMENT

Varus/valgus axis was determined by the intercondylar intermalleolar distance while standing. Soccer and tennis players were compared on knee axis and other outcome variables by analysis of covariance, adjusting for age and by t-tests within age groups.

RESULTS

A significantly higher prevalence of knee varus was found among the soccer players compared to that among the tennis players. The difference in intracondylar distance was statistically significant after the age of 13 years (P < 0.001). In addition, compared to tennis players, soccer players had higher foot arches, decreased hip external rotation and increased external tibial torsion.

CONCLUSIONS

Varus knee axis deviation was more common among children and adolescent soccer players than among tennis players. The prevalence was more pronounced among players aged 13 years or older. Further research is needed to explore the rationale of this phenomenon.

[The role of patellar lateral release and augmentation of median retinaculum of patellae in treatment of femoro-patellar malalignment]

Patellar misalignment is more common than usually supposed; many patients learn to live with this affection without seeing a doctor. A large number of open surgical procedures were described for treatment of misalignment of extensor mechanism of knee. We want to present our method which consisted in arthroscopic lateral release and augmentation of medial retinaculum. We had 47 patients with femoro-patellar misalignment treated with this method. The results were appreciated by clinical and radiological criteria (patellar glide test, patellar tilt test, Macnab scores, Merchant angle). The follow-up was two years. Only 17% had recurrence of clinical signs.

Magnetic resonance imaging evaluation of patellofemoral malalignment

PURPOSE

The purpose of this study was to determine the relationship between anterior knee pain secondary to suspected patellofemoral malalignment and tibial tubercle lateralization, patellar tilt, and patellar lateralization on magnetic resonance imaging.

METHODS

We compared the bony relationships of the knee in patients with anterior knee pain and patients with nonspecific internal derangements of the knee. We measured the lateral deviation of the tibial tubercle and the patella from the trochlea, patellar tilt, and patellar and patellar tendon length.

RESULTS

The symptomatic knees of patients with anterior knee pain had significantly (P < or = .01) greater lateralization of the tibial tubercle and lateral patellar tilt than did knees of the control group. Patella alta appears to be more common in subjects with anterior knee pain.

CONCLUSIONS

Magnetic resonance imaging determination of tibial tubercle lateralization and patellar tilt correlates positively with the clinical diagnosis of anterior knee pain, suggesting that patellofemoral pain is caused by subtle malalignment.

LEVEL OF EVIDENCE

Level III, development of diagnostic criteria on basis of nonconsecutive patients.

Biomechanical background and clinical observations of rotational malalignment in TKA: literature review and consequences

Malalignment, in particular femoral component malrotation, is a commonly accepted failure mode in total knee arthroplasty. The general objective of this paper is twofold: firstly, it accentuates clinical observations of the effects of rotational malalignment in total knee arthroplasty. Secondly, it discusses the relevant parameters of existing knee joint models with regards to rotational malalignment and its biomechanical background, thereby setting a basis for future studies. To summarise, when modelling malalignment in total knee arthroplasty, the following aspects should be considered: Friction between the implant components, ligamentous and capsular structures, deformable body to model the PE inlay, and an in vivo validation of the model. Because of the large variance in anthropometrical data between individuals, future knee joint models should also incorporate individual data.

A new methodology for the planning of single-cut corrective osteotomies of mal-aligned long bones

BACKGROUND

Corrections of combined torsional and angular deformities of long bones may be performed creating a single osteotomy which is oriented so that rotating the two fragments on the created osteotomy plane allows to correct all deformities in one step. A practical geometrical tool is presented to facilitate the difficult preoperative planning of such osteotomies.

METHODS

The geometrical tool consists of two limbs connected by a mobile disk representing the osteotomy plane. This allows the two limbs to be deliberately bent and rotated against each other. Thereby, the mobile disk will change orientation in such a way that it will indicate the osteotomy plane needed in order to anatomically align the two limbs. The geometrical principle of the tool has been confirmed mathematically and compared with data from the literature. Five deformed test bones have been used to test the effectiveness of the tool.

FINDING

. The geometrical principle of the tool is equivalent with the mathematical data from the literature. The maximal osteotomy angle which can be indicated by the tool is 65 degrees , with an error of +/-3 degrees compared to mathematically calculated values. The five test bones were all aligned anatomically with appropriate accuracy.

INTERPRETATION

The presented tool can be easily used and facilitates largely the preoperative planning of a single cut osteotomy for complex deformities of long bones. It allows to avoid sophisticated mathematical calculations and helps to avoid the risk for errors in planning and performing correctional osteotomies.

Delayed gadolinium-enhanced magnetic resonance imaging of cartilage in knee osteoarthritis: Findings at different radiographic stages of disease and relationship to malalignment

OBJECTIVE

Delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) is used to examine the distribution of glycosaminoglycan in cartilage. This study sought to characterize dGEMRIC in the evaluation of knee osteoarthritis (OA) according to various radiographically determined disease parameters, and to examine the relationship between alignment of the knee joint and the lateral:medial dGEMRIC ratio.

METHODS

Thirty-one patients with knee OA underwent MRI with a dGEMRIC protocol at 1.5T. Semiflexed knee radiographs and full-limb radiographs were also obtained for assessment of alignment.

RESULTS

Compartments of the knee joint without joint space narrowing had a higher dGEMRIC index than those with any level of narrowing (mean 408 msec versus 365 msec; P = 0.001). In knees with 1 unnarrowed (spared) and 1 narrowed (diseased) compartment, the dGEMRIC index was greater in the spared versus the diseased compartment (mean 395 msec versus 369 msec; P = 0.001). In spared compartments, there was a trend toward a lower dGEMRIC index with increasing Kellgren/Lawrence (K/L) radiographic severity grade; the spared compartments of knees with a K/L grade 2 had a higher dGEMRIC index than those of knees with a K/L grade 4 (mean 425 msec versus 371 msec; P < 0.05). There was a range of dGEMRIC values in the spared compartments within a given K/L grade, demonstrating biochemical differentiation of disease in radiographically comparable compartments. Almost all compartments with narrowing had dGEMRIC indices of <400 msec. Valgus-aligned knees tended to have lower dGEMRIC values laterally, and varus-aligned knees tended to have lower dGEMRIC values medially; as a continuous variable, alignment correlated with the lateral:medial dGEMRIC ratio (Pearson's R = 0.43, P = 0.02).

CONCLUSION

The biochemical information provided by dGEMRIC scans may augment radiography by improving the differentiation of disease status within a given radiographic grade, especially in early OA.

Imaging of patellofemoral disorders

Anterior knee pain is a common symptom, which may have a large variety of causes including patellofemoral pathologies. Patellofemoral maltracking refers to dynamic abnormality of patellofemoral alignment and has been measured using plain film, computed tomography (CT) and magnetic resonance imaging (MRI) using static and kinematic techniques. Patellar dislocation is usually transient, but specific conventional radiographic and MRI features may provide evidence of prior acute or chronic dislocation. In addition, chondromalacia patellae, osteochondritis dissecans, patellofemoral osteoarthritis, excessive lateral pressure syndrome, and bipartite patella have all been implicated in causing patellofemoral pain. The imaging and clinical features of these processes are reviewed, highlighting the specific diagnostic features of each condition.

Three-dimensional lower extremity alignment assessment system: application to evaluation of component position after total knee arthroplasty

A 3-dimensional (3D) lower extremity alignment assessment system based on biplanar computed radiography, a camera calibration procedure, and 3D image fitting techniques was developed. The goal of this study was to examine the errors associated with applying this 3D technique to determine component alignment after total knee arthroplasty (TKA). Tibial and femoral component alignment after TKA (varus--valgus, flexion-extension, and internal--external angulations) in 4 patients was determined directly with reconstructions from computed tomography (CT) scans and indirectly with the proposed bone and component image fitting techniques. Mean differences between alignment values from the CT and image fitting techniques ranged from 0.18 degrees to 0.78 degrees, and maximum differences ranged from 0.30 degrees to 0.90 degrees. The proposed 3D method can be reliably used to assess component alignment after TKA.

[Posteromedial bowing of the lower leg and neuroblastoma with possible neurofibromatosis type I: a case report and literature review]

BACKGROUND

The posteromedial bowing of the tibia is a rare condition that is not yet known to be related to neurofibromatosis. The case of a three month-old boy with the tentative diagnosis of neurofibromatosis is described. He developed paraplegia due to an abdominal neuroblastoma at the age of 9 months. This led us to a review of the literature.

METHOD

122 cases of posteromedial bowing of the tibia in 20 publications of the years 1949 - 2000 were analysed under special respect to gender, side of affection, shortening of the lower leg, treatment and possible cause.

RESULTS

The posteromedial bowing of the lower leg seems to affect more boys as well as the left side. As far as described in all but one case it was the first delivery. Regularly, a limb shortening and pes calcaneovalgus is to be found. 99 children were treated conservatively, 21 got an operation of the affected side. In 19 performed osteotomies no pseudarthrosis occurred. One case of a fracture due to an adequate trauma without healing problems is described.

Reproducibility and reliability of the anatomic axis of the lower extremity

Two observers measured the tibiofemoral angle of 60 knees on hip-knee-ankle and anteroposterior (AP) knee radiographs and repeated the measurements 6 months later. Intraobserver reproducibility was moderate. Interobserver reliability was poor. These findings were the same irrespective of which radiograph was used during the measurement. Hence, although an AP knee radiograph was as reliable and reproducible as the hip-knee-ankle view, the radiographic tibiofemoral angle should not be considered a precise measurement.

Repair of malunions after ankle arthrodesis

Ankle arthrodesis is an operation that produces fusion of the talocrural joint. Ideally, the ankle is fused in a position of slight valgus, neutral dorsiflexion, midsagittal translation, slight posterior translation, symmetric external rotation, and plantigrade foot alignment. Malunion after ankle arthrodesis is characterized as a deviation from this ideal position. The derangement may produce inefficient or painful gait and pain or dysfunction at the hip, knee, or foot. Preoperative planning is essential to achieve a final plantigrade foot position. Correction is accomplished through the ankle arthrodesis itself, the foot, or the supramalleolar tibia. Complications of ankle malunion repair include nonunion; malunion; nerve, vessel or tendon injury; and infection.

Management of patellofemoral pain targeting hip, pelvis, and trunk muscle function: 2 case reports

STUDY DESIGN

Case report.

OBJECTIVE

To describe an alternative treatment approach for patellofemoral pain.

BACKGROUND

Weakness of the hip, pelvis, and trunk musculature has been hypothesized to influence lower-limb alignment and contribute to patellofemoral pain. Two patients who had a chief complaint of patellofemoral pain and demonstrated lack of control of the hip in the frontal and transverse planes during functional movements were treated with an exercise program targeting the hip, pelvis, and trunk musculature.

METHODS AND MEASURES

The patients presented in these 2 case reports did not exhibit obvious patellar malalignment or tracking problems; however, on qualitative assessment, both demonstrated excessive hip adduction, internal rotation, and knee valgus during gait and while performing a step-down maneuver. In addition, both patients exhibited weakness of the hip abductors, extensors, and external rotators, as demonstrated by hand-held dynamometry testing. Treatment in both cases occurred over a 14-week period and focused on recruitment and endurance training of the hip, pelvis, and trunk musculature. Functional status, pain, muscle force production, as well as subjective and objective assessment of lower-extremity kinematics during gait and a step-down maneuver were assessed preintervention and postintervention.

RESULTS

Both patients experienced a significant reduction in patellofemoral pain, improved lower-extremity kinematics during dynamic testing, and were able to return to their original levels of function. Gluteus medius force production improved by 50% in patient A and 90% in patient B, while gluteus maximus force production improved 55% in patient A and 110% in patient B. Objective kinematic improvements in the step-down task also were demonstrated in patient A.

CONCLUSION

Assessment and treatment of the hip, pelvis, and trunk musculature should be considered in the rehabilitation of patients who present with patellofemoral pain and demonstrate abnormal lower-extremity kinematics.

Die Bestimmung des AT- und CCD-Winkels am mazerierten Leichenfemur - Eine Vergleichsstudie zwischen CT- und MRT-Messung und Direktmessung am Präparat

PURPOSE

To compare measurements of the real AT (femoral antetorsion) and CCD (caput-collum-diaphysis) angle by computed tomography (CT) and magnetic resonance imaging (MRI) of hip specimen using direct measurements as reference standard, and to show that measurement by MRI can replace CT measurements and may help avoiding X-ray exposition.

MATERIALS AND METHODS

CT and MRI measurements were obtained on 25 in water-arrested macerated human femora. Postprocessing was done by 4 independent readers on a workstation using a dedicated 3D-software. Direct measurements of the real AT and the CCD angle were used as reference standard. The analysis included Student's t test for paired values, interobserver variability using intra-class correlation coefficients (ICC), maximum and middle divergence of the angles, and Bland-Altman plots.

RESULTS

For determining AT and the CCD angle with CT and MRI, good correlation was found between the 4 readers and with measurements using the reference standard. ICCs were 0.97 and 0.90 for measuring AT and CCD angle with CT, and 0.95 and 0.71 for measurements with MRI, respectively. Mean divergence between CT measurements and those of the reference standard was 0.8 degrees for AT and 0.7 degrees for the CCD-angle. Mean divergence between MRI measurements and those of the reference standard was 0.3 degrees for AT and -0.4 degrees for the CCD-angle. Mean divergences between CT and MRI measurements of AT and CCD-angle were 0.5 degrees. Neither systematic errors nor dependences on the qualitative size of the reference data were evident in the divergences of measurements.

CONCLUSION

Measurements of the real AT and CCD angle by CT and MR imaging revealed a good correlation with direct measurements of the femoral specimen and consequently can be recommended for clinical use. MRI measurements can replace CT measurements, avoiding X-ray exposure especially in young patients undergoing preoperative evaluation for hip dysplasia.

Electromyography of the quadriceps in patellofemoral pain with patellar subluxation

This study compared muscle activity and timing of gait phases during functional activities in 13 subjects with patellofemoral pain associated with lateral subluxation and in 11 subjects with healthy knees. Fine wire electromyography recorded activity in the vastus lateralis and vastus medialis oblique during walking and ascending and descending stairs. Subjects were filmed to divide the activities into phases and determine timing. The vastus medialis oblique and vastus lateralis had similar patterns during all activities. Subjects with patellofemoral pain had significantly increased activity in the vastus medialis oblique and vastus lateralis compared with the healthy subjects during the most demanding phases of the gait cycle, suggesting a generalized quadriceps weakness in the patients with patellofemoral pain. Timing differences were seen in walking and stair ascending with the subjects with patellofemoral pain spending significantly more time in stance compared with the healthy subjects. This may be an attempt to reduce the load on weak quadriceps. These data reflect a generalized quadriceps muscle weakness, rather than the prevailing theory of quadriceps muscle imbalance as an etiology of patellofemoral pain. Therefore, we support the practice of strengthening the entire quadriceps muscle group, rather than attempting to specifically target the vastus medialis oblique.

Hydroxyapatite coating of external fixation pins to decrease axial deformity during tibial lengthening for short stature

BACKGROUND

Tibial valgus, a known complication of leg lengthening with external fixation techniques, has been related to the stability of the bone-fixator system and, in particular, to pin loosening. A hydroxyapatite coating has been reported to enhance the quality of the bone-pin interface. The aim of this study was to compare the prevalence of axial deformity after tibial lengthening with hydroxyapatite-coated external fixation pins with the prevalence after tibial lengthening with uncoated pins.

METHODS

We conducted a prospective study of thirty-four symmetrical tibial lengthening procedures in seventeen pathologically short patients. One limb of each patient was lengthened with use of hydroxyapatite-coated pins and the other, with standard uncoated pins; the sides of the operations were randomly selected. The bone angle in the frontal plane was measured before the operation and at the end of the fixation period, and the difference between these measurements was compared between the lengthening procedures performed with coated pins and those performed with uncoated pins.

RESULTS

The mean valgus deviation of the tibia was 6.5 degrees in the group treated with hydroxyapatite-coated pins and 12.5 degrees in the group treated with uncoated pins (p = 0.023). With the numbers available, other factors previously related to the development of valgus deformity did not differ significantly between the two groups.

CONCLUSION

Tibiae that are lengthened with the use of hydroxyapatite-coated external fixation pins are less prone to axial deviation in the frontal plane than are those treated with uncoated pins.

LEVEL OF EVIDENCE

Therapeutic study, Level I-1a (randomized controlled trial [significant difference]). See Instructions to Authors for a complete description of levels of evidence.

Incremental diagnostic value of 99mTc methylene diphosphonate bone SPECT in patients with patellofemoral pain disorders

Painful disorders of the patellofemoral joint are one of the most frequent complaints in orthopaedic and sports medicine. The purpose of this study was to assess the value of single photon emission computed tomography (SPECT) bone imaging compared with arthroscopy in the differential diagnosis of anterior knee pain. Twenty-seven patients with chronic anterior knee pain and 27 age matched control patients were examined prospectively. All patients underwent a detailed clinical history and a thorough physical examination of the knee. Planar and SPECT knee scintigraphy was performed using 99mTc methylene diphosphonate (99mTc-MDP). Subsequently, arthroscopic examination of all three compartments of the affected knee was performed. The association between the scintigraphic findings and arthroscopy was examined statistically. Planar and SPECT scintigrams were classified as follows: focal or diffuse uptake in the patella only (eight patients), uptake in the patella and a corresponding focus in the distal femur (12 patients), and uptake in the patella associated with linear increased activity along the distal femur (six patients). One patient had no patellofemoral SPECT abnormalities. Six of eight patients with isolated increased patellar activity were diagnosed with chondromalacia of the patella, while 2/8 patients had arthroscopic findings unrelated to patellofemoral abnormalities. Seven of 12 patients with corresponding uptake in the patella and distal femur were diagnosed with patellofemoral arthritis. Eleven other patients with corresponding patellar and femoral activity were diagnosed with increased lateral patellar compression syndrome. In these patients the patellar foci were always lateral, and they separated during flexion of the knee. Seven patients had further scintigraphic findings in addition to patellofemoral abnormalities, unsuspected clinically. Nine of 27 patients in the control group (33%) had either focal or diffuse increased patellar uptake. Compared to arthroscopy SPECT imaging had a sensitivity of 100% for patellofemoral abnormalities and a specificity of 64% (negative predictive value, 100%; and positive predictive value, 72%). The overall observed agreement between SPECT and arthroscopy was 81% (kappa=0.63). It is concluded that SPECT imaging of the knee is highly sensitive for the diagnosis of patellofemoral abnormalities. SPECT significantly improves the detection of maltracking of the patella and the ensuing increased lateral patellar compression syndrome. This information could be used to treat patellofemoral problems more effectively.

Operation planning of correction osteotomies in 3D

This paper discusses an operation planning system for correction osteotomies. It is based on 3D data obtained from CT/MR of the bone and it allows to perform a 3D planning. The physician can individually determine anatomical landmarks for measuring geometric parameters of the bone like length, angle and torsion angle. In a virtual scene he or she can set a single cut or can remove/insert a wedge, dissecting the bones. The bone parts can be rearranged in 3D space. Optimization routines allow that the physician only defines the position of the cut, the orientation of the cut plane, the rearrangement of the bone and the optimization for the maximal overlap of the cortical bone can be processed automatically. The system is currently in use at the Trauma department at the University of Ulm. A case study shows the results by applying this system.

[Rupture of the gluteus medius tendon]

AIM

Rupture of the gluteus medius tendon is a rare, even neglected condition. Typical findings include local tenderness and weakness of hip abduction. This pathologic condition is very seldom analysed in the literature, there is no report about the meaning in primary total hip replacement (THR).

PATIENTS

Between 1/1/1995 and 12/31/2000 we found 13 cases (3,5 %) with a tear of the gluteus medius tendon in 372 primary THR using the lateral approach. In all cases the rupture was seen in the ventral and lateral part of the gluteus medius tendon. Furthermore, a valgus position of the proximal femur was detected. Transosseous refixation of the tendons was performed in all cases. 3 months after operation local tenderness near the greater trochanter disappeared and full strength of the pelvitrochanteric muscles was achieved in 11 out of 13 cases and in the remaining cases after one year.

CONCLUSION

When a valgus position of the proximal femur in primary THR is found, one has to be aware of a simultaneous rupture of the gluteus medius tendon. This pathologic finding has to be ruled out preoperatively by means of ultrasound or MRI and an adequate approach to the hip joint has to be selected to examine the pelvitrochanteric muscles and to treat the rupture.

[Osteotomies in malalignments of the lower extremities]

The surgical correction of malalignments of the lower extremities is a very demanding procedure. It requires extensive knowledge of: (1) fundamental lower extremity biomechanics, (2) various diagnostic modalities, and (3) methodology for multidimensional preoperative planning. Despite advanced techniques in diagnostics and surgery, the history of the patient and a physical examination are still the first steps in the diagnostic chain. The knowledge of the method-dependent normal values, their physiological range and intra-individual differences are a prerequisite. In posttraumatic deformities, the healthy leg is a good reference for the patient's geometric orientation. As a rule, values differing by three times the standard deviation or more are good indications for an operation. These are 15 and 12 mm for the upper and lower leg, 18 and 15 mm for the whole leg and only 3 degrees mm for the mechanical leg axis measured using computer tomography and long standing x-rays, respectively. The indication for surgical correction is not only based on geometric data. The patient's functional needs, symptoms, complaints and compensation possibilities must also be taken into account. The lower extremities have to be assessed in a psychosocial context. Among the huge number of possible surgical techniques, the procedure best suited for the patient has to be selected. This requires extensive knowledge and advanced technical skills from the treating orthopaedic surgeon. In supracondylar or high tibial osteotomies for the treatment of medial arthritis of the knee joint, the patient should be informed of the long term prognosis and endoprosthetic alternatives. Today, percutaneous epiphysiodesis is a very reliable and minimally invasive surgical technique for correcting the length and axis of the lower extremity in children between 10 and 14 years. With well planned epiphysiodesis procedures, it is often possible to avoid complex osteotomies in younger patients.

Analysis of limb alignment in the pathogenesis of osteoarthritis: a comparison of Saudi Arabian and Canadian cases

A study was made of alignment abnormalities and bone deformities in Saudis with osteoarthritis (SOA). Data from standardized radiography of hips and knees were: hip-knee-ankle angle (HKA), condylar-hip angle (CH), tibial plateau-ankle angle (PA), and joint surface (condylar-plateau) angle (CP). Females dominated the <50 years SOA subgroup (1.8:1), having also early onset OA with severe bowlegged deformity (mean HKA -11 degrees) and major shifts in CH, PA, and CP relative to normal parameters. In the females, links were noted between severe disease and osteomalacia or osteoporosis, requiring prospective studies. An association between femoral deformity (CH) and OA, first reported in Canadians with OA (COA), was confirmed in SOA (especially in males of all ages). The condition implies heightened mechanical risk of onset or progression at medial joint surfaces. Further, it calls for the fresh appraisal of surgical options based on biomechanical analysis of each case, including femoral osteotomy where necessary.

The inter-tester reliability of a clinical measurement used to determine the medial-lateral orientation of the patella

An important aspect of the patellar taping technique, a common treatment for patellofemoral pain is the assessment of patellar position. The inter-tester reliability of the assessment method has been regarded as poor, as has the validity (Powers et al. 1999). The purpose of the study was to determine inter-tester reliability of a group of trained manual physiotherapists. This was achieved using a clinical measurement to assess the medial/lateral orientation of the patella and compare these findings against a known criterion valid measurement of patella position. Twenty experienced manual physiotherapists evaluated medial/lateral orientation of the patella. The findings of the clinical assessment were then compared to the position of the patella as determined through magnetic resonance imaging (MRI). The MRI and the clinical assessment were carried out on the right knee of a single subject, who was supine with the knee in 20 degree flexion with the quadriceps relaxed. Both measures found the patella to be laterally displaced. Using the clinical method the mean difference between medial and lateral measurements was 6.4 mm (+/- 3.9 mm). The MRI measure of lateral patella displacement found the patella to be displaced 5 mm laterally. The inter-tester reliability of the clinical test showed good agreement, r = 0.91 for the medial measure and r = 0.94 for the lateral measure. The agreement between the clinical and MRI measures was (r = 0.9) which was also a significant agreement. This study appears to demonstrate that experienced manual physiotherapists can reliably measure relative patella medial/lateral position.

[Axis deviation, cartilage damage and cruciate ligament rupture--concomitant interventions in replacement of the anterior cruciate ligament]

BACKGROUND

Osteochondral lesions and osteoarthritis in young patients are often caused by chronic knee instability and varus malalignment. We present the indications, operative technique, and results for the combined operation of high tibial osteotomy and cruciate ligament reconstruction.

MATERIALS AND METHODS

From April 1996 until December 2000, 58 patients (average age: 33 years) underwent simultaneous osteotomy (57 correcting valgus, 1 valgus malalignment) and cruciate ligament reconstruction (49 ACL, 7 PCL, 2 ACL & PCL) which was routinely performed with an arthroscopic technique after completion of the osteotomy (closed wedge technique). Average correction angle of the osteotomy was 7 degrees (4-10 degrees) with a mean malalignment of 5 degrees (0-10 degrees). Thirteen patients underwent additional cartilage surgery (osteochondral autograft transplantation, autologous chondrocyte transplantation, microfracturing), and two patients were implanted with a collagen meniscus (CMI) at the same time.

RESULTS

Preoperatively the Lysholm score was 66 (35-81) points and increased to 81 (74-95), 87 (79-99), and 93 (88-99) points 3, 6, and 12 months after surgery, respectively. Subjectively all patients reported an improvement of preoperative swelling, pain, and instability. Additional cartilage surgery or meniscus implantation did not significantly alter the clinical score values. Complications were noted in four patients.

CONCLUSIONS

Unstable knees with varus malalignment can be sufficiently treated by osteotomy and cruciate ligament reconstruction at the same time, suggesting that unicompartimental decompression and treatment of instability is a causal and cost-effective therapy delaying the progression of osteoarthritis and minimizing clinical symptoms. Performing both operations in one procedure facilitates early rehabilitation and the return of these patients to the activities of daily living and sports.

Acute effects of the Protonics system on patellofemoral alignment: an MRI study

This study used magnetic resonance imaging (MRI) to determine whether changes in patellofemoral alignment occur after initial treatment with the Protonics exercise device. The first scan was obtained before the device was used. After performing a set of exercises with no resistance on the device the device was removed, and a second scan was obtained. The same set of exercises was again performed with resistance on the device set at the appropriate level, and a final scan was obtained with the device removed. An isometric leg press was maintained as each image was obtained to simulate more closely a functional weight-bearing activity. Subjects were 26 women with complaints of patellofemoral pain. The main outcome measures were: patellar tilt angle, bisect offset, and lateral facet angle. Nonparametric repeated measures analysis of variance tests showed no differences between test conditions for any of the three measures of patellofemoral alignment. We conclude that after an initial treatment session using the Protonics system there is no change in patellofemoral alignment as determined by MRI.

MRI study of talonavicular alignment in club foot

We studied in vivo the talonavicular alignment of club foot in infants using MRI. We examined 26 patients (36 feet) with congenital club foot. The mean age at examination was 9.0 months (4 to 12). All analyses used MRI of the earliest cartilaginous development of the tarsal bones in the transverse plane, rather than the ossific nucleus. The difference in the mean talar neck angle (44.0 +/- 8.1 degrees) in club foot was statistically significant (p < 0.001) when compared with that of the normal foot (30.8 +/- 5.5 degrees). The difference between the mean angles in the group treated by operation (47.9 +/- 6.7 degrees) and those treated conservatively (40.1 +/- 7.5 degrees) was also statistically significant. The anatomical relationship between the head of the talus and the navicular was divided into two patterns, based on the position of the mid-point of the navicular related to the long axis of the head. In the operative group, 18 feet were classified as having a medial shift of the navicular and none had a lateral shift. In the conservative group, 12 showed a medial shift of the navicular and six a lateral shift. All nine unaffected normal feet in which satisfactory MRI measurements were made showed a lateral shift of the navicular. Club feet had a larger talar neck angle and a more medially deviated navicular when compared with normal feet. This was more marked in the surgical group than in the conservative group.

Reliability of the lateral pull test and tilt test to assess patellar alignment in subjects with symptomatic knees: student raters

STUDY DESIGN

Test-retest reliability with blinded testers.

OBJECTIVES

To determine the inter- and intra-rater reliability of the lateral pull test and patellar tilt test.

BACKGROUND

If patellar malalignment can be detected by clinical examination, then condition-specific treatment interventions may be implemented in patients with patellofemoral pain syndrome. However, several clinical tests used to assess patellar mobility have recently been shown to have poor to fair reliability. Because the lateral pull test and the patellar tilt test are widely used clinically as diagnostic tests for patellofemoral pain syndrome but have not been previously tested for reliability, we examined these tests.

METHODS AND MEASURES

Fifty-two subjects (age range, 21-48 years) provided 95 knees (19 symptomatic and 76 asymptomatic) for assessment of the lateral pull test. Two testers, blinded to the presence or absence of symptoms, independently performed the lateral pull test in random order. Fifty-five subjects (age range, 22-42 years) provided 99 knees (73 asymptomatic and 26 symptomatic) for assessment of the patellar tilt test. Three blinded testers independently performed the patellar tilt test in random order. All subjects were tested and retested within 3-5 days. A kappa (kappa) statistic was used to assess the agreement of findings within each tester and between testers.

RESULTS

The kappa coefficients for intrarater reliability varied from 0.39 to 0.47 for the lateral pull test and from 0.44 to 0.50 for the patellar tilt test, while the coefficients for interrater reliability were 0.31 for the lateral pull test and varied from 0.20 to 0.35 for the tilt test.

CONCLUSIONS

Repeated lateral pull tests and patellar tilt tests had fair intrarater and poor interrater reliability. Our results suggest that care must be taken in placing too much emphasis on these tests when making clinical decisions.

Magnetic resonance imaging of growth plate injuries: the efficacy and indications for surgical procedures

In 23 patients with growth plate injuries, magnetic resonance imaging (MRI) studies were performed a total of 31 times to evaluate the physis which showed plain radiographic evidence of possible damage. Fourteen patients clinically showed growth arrest, and 10 patients required a Langenskiold operation. In 3 patients who underwent this operation, subsequent premature total fusion of the physis adversely affected the postoperative results. We propose that the merging shape of the arrest line with calcification of the provisional zone of the metaphysis shown by MRI indicates poor viability of the physis. MRI provided useful information on the appearance of the growth plate and changes in the metaphysis, both of which affected the prognosis and the results of the surgical procedures.