Unilateral anterior knee pain is associated with increased patellar lateral position after stressed lateral translation.

PURPOSE: To objectively compare side-to-side patellar position and mobility in patients with idiopathic unilateral anterior knee pain (AKP) using a stress-testing device concomitantly with magnetic resonance imaging. It is hypothesized that the painful knees present greater patellar mobility than the contralateral non-painful knees. METHODS: From a total sample of 359 patients, 23 patients with idiopathic unilateral AKP (30.9 years, 23.4 kg/m2, 43% males) were included within the present study. Both knees of all the patients were examined by conventional imaging, including the measurement of trochlear sulcus angle, Caton-Deschamps index, tibial tuberosity to trochlear groove distance, patellar tilt angle and patellar subluxation (both at rest and upon quadriceps contraction). Additionally, the same patients underwent stress testing (Porto Patella Testing Device); these measurements were taken with the patella at rest, after lateral patellar translation and after lateral patellar tilt. Clinical and functional outcomes were obtained using physical examination and the Kujala and Lysholm scores. RESULTS: Painful knees showed statistically significant higher patellar lateral position after stressed lateral translation than non-painful knees (p = 0.028), 9.8 ± 3.6 mm and 7.1 ± 6.3 mm, respectively. The adjusted multivariate logistic model identified the patellar position after lateral displacement to be significantly associated with AKP (OR = 1.165) and the model (AUC = 0.807, p < 0.001) showed reasonable sensitivity (67%) and specificity (73%). CONCLUSION: Patients with idiopathic unilateral AKP with morphologically equivalent knees showed statistically significant increased patellar lateral position after stressed lateral displacement in their painful knee. The greater lateral patellar mobility quantified by the PPTD testing brings more objectivity to the diagnosis. LEVEL OF EVIDENCE: II.

Congenital Pseudarthrosis of the Fibula: Controlling Ankle Valgus in a Heterogenous Condition.

BACKGROUND: Congenital pseudarthrosis of the fibula (CPF) is a rare disorder characterized by a deficiency in the continuity of the fibula and can lead to progressive ankle valgus malalignment. An existing classification system for CPF is imperfect and may contribute to heterogeneity in reporting and discrepancy of outcomes in the literature. METHODS: Fifteen patients with CPF treated at our institution between 1995 and 2017 were retrospectively identified. Only patients with dysplasia leading to spontaneous fracture or pseudarthrosis were included in this series. The median age at presentation was 2.5 years (range: 3 mo to 13.4 y). The median duration of follow-up from the initial presentation was 11.8 years (range: 2.0 to 24 y). Chart review and serial radiographs were analyzed to assess natural history and outcomes following surgery. RESULTS: The coexistence of tibial dysplasia in CPF is very common. Patients were classified into 3 groups based on the degree of tibial involvement-group 1: no evidence of tibial dysplasia, group 2: mild tibial dysplasia, and group 3: significant tibial dysplasia. Age at presentation and age at which fibular fracture occurred were progressively younger with a greater degree of tibial involvement (P<0.05). In the absence of surgical intervention, group 1 patients did not undergo progressive ankle valgus (defined as the valgus change in tibiotalar angle by ≥4 degrees), whereas all patients in groups 2 and 3 did (P<0.001). Fibular osteosynthesis was performed in 6 patients, with union seen only in group 1 patients. Ten patients underwent distal tibiofibular fusion, with no cases of nonunion seen. Distal tibiofibular fusion with or without medial distal tibial hemiepiphysiodesis halted the progression of ankle valgus in 8 of the 10 patients. Further progression of ankle valgus occurred only in patients who did not undergo concurrent medial distal tibial hemiepiphysiodesis and with considerable wedging of the distal tibial epiphysis at the time of fusion. CONCLUSIONS: Tibial dysplasia and CPF are intimately related. Grouping patients on this basis may help guide natural history and treatment and may explain discrepancies in findings in the literature. Fibular osteosynthesis, distal tibiofibular fusion, and medial distal tibial hemiepiphysiodesis may all have an important role in the treatment of CPF. LEVEL OF EVIDENCE: Level IV-case series.

Predicting the mechanical hip-knee-ankle angle accurately from standard knee radiographs: a cross-validation experiment in 100 patients.

Background and purpose - Being able to predict the hip-knee-ankle angle (HKAA) from standard knee radiographs allows studies on malalignment in cohorts lacking full-limb radiography. We aimed to develop an automated image analysis pipeline to measure the femoro-tibial angle (FTA) from standard knee radiographs and test various FTA definitions to predict the HKAA. Patients and methods - We included 110 pairs of standard knee and full-limb radiographs. Automatic search algorithms found anatomic landmarks on standard knee radiographs. Based on these landmarks, the FTA was automatically calculated according to 9 different definitions (6 described in the literature and 3 newly developed). Pearson and intra-class correlation coefficient [ICC]) were determined between the FTA and HKAA as measured on full-limb radiographs. Subsequently, the top 4 FTA definitions were used to predict the HKAA in a 5-fold cross-validation setting. Results - Across all pairs of images, the Pearson correlations between FTA and HKAA ranged between 0.83 and 0.90. The ICC values from 0.83 to 0.90. In the cross-validation experiments to predict the HKAA, these values decreased only minimally. The mean absolute error for the best method to predict the HKAA from standard knee radiographs was 1.8° (SD 1.3). Interpretation - We showed that the HKAA can be automatically predicted from standard knee radiographs with fair accuracy and high correlation compared with the true HKAA. Therefore, this method enables research of the relationship between malalignment and knee pathology in large (epidemiological) studies lacking full-limb radiography.

Risk factor heterogeneity for medial and lateral compartment knee osteoarthritis: analysis of two prospective cohorts.

OBJECTIVE: To evaluate the etiologic heterogeneity between medial and lateral tibiofemoral radiographic osteoarthritis (ROA). METHODS: Knees without medial or lateral tibiofemoral ROA at baseline were followed for 60-month in Multicenter Osteoarthritis Study (MOST) and for 48-month in Osteoarthritis Initiative (OAI). We examined the relation of previously reported risk factors to incident medial and lateral tibiofemoral ROA separately and determined the etiology heterogeneity with a ratio of rate ratios (RRs) (i.e., the RR for medial tibiofemoral ROA divided by the RR for lateral tibiofemoral ROA) using a duplication method for Cox proportional hazard regression. RESULTS: Of 2,016 participants in MOST, 436 and 162 knees developed medial or lateral tibiofemoral ROA, respectively. Obesity and varus malalignment were 95% and 466% more strongly associated with incident medial tibiofemoral ROA than with lateral tibiofemoral ROA, respectively (ratios of RRs, 1.95 [95% confidence interval (CI):1.05-3.62] and 5.66 [95% CI:3.20-10.0]). In contrast, the associations of female sex and valgus malalignment with incident medial tibiofemoral ROA were weaker or in an opposite direction compared with lateral tibiofemoral Osteoarthritis (OA) (ratios of RRs, 0.40 [95% CI:0.26-0.63] and 0.20 [95% CI:0.12-0.34], respectively). Older age tended to show a weaker association with incident medial tibiofemoral ROA than with incident lateral tibiofemoral ROA. No heterogeneity was observed for the relation of race, knee injury, or contralateral knee ROA. These findings were closely replicated in OAI. CONCLUSION: Risk factor profiles for medial and lateral tibiofemoral ROA are different. These results can provide a framework for the development of targeted prevention and potential treatment strategies for specific knee OA subtypes.

The Nonsurgical Management of Orbital Dystopia Using Refractive Lenses and Prosthetic Shells.

Surgical rehabilitation of orbital dystopia can be challenging. The authors demonstrate the effective use of spectacle lenses to visually correct misalignments of the globe and the orbit. Presented is a retrospective review of 4 patients undergoing aesthetic rehabilitation through use of spectacle lenses and in a number patients a cosmetic shell.Two patients with neurofibromatosis presented with inferior dystopia of the globe and orbit. A base-down prismatic lens applied to the spectacles in conjunction with a prosthetic shell successfully visually corrected the facial asymmetry and improved patients' aesthetic appearance. One patient with a history of traumatic retinal detachment, who did not want any surgical intervention, a "plus" (hypermetropic) lens was used to magnify the perceived image of an enophthalmic and phthisical globe, to enhance appearance and improve symmetry. In the fourth patient, with Goldenhar syndrome, the appearance of a hypotropia and concurrent esotropia was successfully treated with a Fresnel prism and a prosthetic shell.This case series illustrates the successful role of various refractive lenses often in conjunction with prosthetic shells in patients with reduced vision and orbital dystopia to improve facial symmetry. This conservative treatment is especially useful when surgery is not a desired or not considered a suitable option for the patient.

Changes in Rearfoot Alignment in Chronic Plantar Heel Pain.

Plantar heel pain is a common disabling condition in adults. Biomechanical factors are important in the development of plantar heel pain. Quantitative changes in rearfoot alignment in patients with plantar heel pain have not been previously investigated. From April 2016 to March 2017, 100 patients with plantar heel pain and 100 healthy individuals were recruited. The foot posture index was used for the measurement of foot alignment. The generalized joint hypermobility condition was assessed using the Beighton scale. The transverse plane talocalcaneal angle, calcaneocuboid angle, talonavicular uncovering angle, calcaneal inclination angle (CIA), talar declination angle, talar-first metatarsal angle, and sagittal talocalcaneal angle were measured on standard weightbearing anteroposterior and lateral foot radiographs. The body mass index was recorded electronically. The distribution of sex, age, weight, body mass index, side, foot posture index score, and Beighton scale were comparable between groups (p > .05). The mean calcaneocuboid angle (p = .009), talonavicular uncovering angle (p = .000), CIA (p = .000), talar declination angle (p = .039), and talar-first metatarsal angle (p = .000) were significantly higher in the plantar heel pain group. In conclusion, our study has demonstrated a relationship between chronic plantar heel pain and the CIA.

[Extracapsular Proximal Femoral Fractures - Retrospective Evaluation of a Group of Patients with a Focus on Complications of Treatment]. / Extrakapsulární zlomeniny proximálního femuru ­ retrospektivní vyhodnocení souboru pacientu se zamerením na komplikace lécby.

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.

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.

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.

Verification of in vivo accuracy of Trumatch™ patient-specific instrumentation in total knee replacement using pin-less computer navigation.

PURPOSE: Accurate component alignment in total knee replacement (TKR) is one of the important factors in determining long-term survivorship. This has been achieved by conventional jigs, computer-assisted technology (CAS) and more recently patient-specific instrumentation (PSI). The purpose of the current study was to investigate the in vivo accuracy of Trumatch™ PSI using validated pin-less computer navigation system. METHOD: Twenty consecutive selected patients that fulfilled our inclusion/exclusion criteria underwent TKR using PSI. Coronal alignment, posterior slope, resection thickness and femoral sagittal alignment were recorded using pin-less navigation. The position of the actual cutting block was appropriately adjusted prior to proceeding to definitive resections. RESULTS: The coronal alignment using PSI without the assistance of navigation would have resulted in 14 (70 %) within ±3°, 11 (55 %) within ±2° and 6 (30 %) outside acceptable alignment. Thirty-five percentage of proposed femur sagittal alignment and 55 % of posterior tibial slope were achieved within ±3°. Components size was accurately predicted in 95 % of femurs and 90 % of tibia. CONCLUSION: The purported advantages in restoring alignments using Trumatch™ PSI alone over standard equipment are debatable. However, it predicts sizing well, and femoral coronal alignment is reasonable. Combining Trumatch™ PSI with CAS will allow in vivo verification and necessary corrections. LEVEL OF EVIDENCE: IV.

Malrotation deformities of the lower extremity and implications on total knee arthroplasty: a narrative review.

INTRODUCTION: Total knee arthroplasty (TKA) is a successful procedure for the management of osteoarthritis (OA) of the knee. Axial plane deformities are more common than suspected in patients presenting with osteoarthritis of the knee joint. Recent research has indicated that torsional deformities could play an important role in the development of anterior knee pain (AKP). METHODS: In a narrative review of the literature, the aetiology of maltorsion deformity of the lower extremity in both, childhood and adulthood, as well as the development of postoperative femoral axial plane deformities are examined. This includes the numerous surgical interventions that have been described for the treatment of maltorsion syndrome, and the role of patient-specific instrumentation. Finally, correcting for maltorsion deformity during and its potential implications for the current clinical care pathway, in terms of both pre- and perioperative practices is discussed. DISCUSSION AND CONCLUSION: Axial plane alignment is considered the 'third dimension' in TKA. Correct axial alignment the lower extremity and of prosthetic components is deemed an important prerequisite for a postoperatively stable and painless knee. Identification of and, where appropriate, adjustment for any pre-existing maltorsion deformities is thought to significantly reduce the proportion of patients with residual complaints following TKA. Well-designed and well-conducted clinical studies are required to support our hypotheses.

[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.

Is end-stage lateral osteoarthritic knee always valgus? Mechanical alignment analysis and radiographic severity assessment.

BACKGROUND: We hypothesized that not all persons with end-stage lateral osteoarthritis (OA) have valgus malalignment and that full extension radiographs may underreport radiographic disease severity. The purpose of this study was to examine the demographic and radiographic features of end-stage lateral compartment knee OA. MATERIALS AND METHODS: We retrospectively studied 133 knees in 113 patients who had undergone total knee arthroplasty between June 2008 and August 2010. All patients had predominantly lateral idiopathic compartment OA according to the compartment-specific Kellgren-Lawrence grade (KLG). The mechanical axis angle (MAA), compartment-specific KLG and joint space narrowing (JSN) of the tibiofemoral joint at extension and 30° of knee flexion, tibia vara angle, tibial slope angle, body mass index, age, and sex were surveyed. RESULTS: End-stage lateral compartment knee OA has varus (37.6 %), neutral (22.6 %), and valgus (39.8 %) MAA on both-leg standing hip-knee-ankle radiographs. KLGs at 30° of knee flexion (fKLG) were grades 3 and 4 in all patients. However, for KLGs at full extension (eKLG), 54 % of all patients had grades 3 and 4. The others (46 %) showed grades 1 and 2. We observed significant differences in lateral compartment eKLG/eJSN (2.3/2.3 mm in varus, 2.5/1.9 mm in neutral, 2.9/1.6 mm in valgus, p = 0.01 and 0.03, respectively), tibia vara angle (4.9° in varus, 4.1° in neutral, 3.0° in valgus, p < 0.01), and medial compartment eKLG/eJSN (2.1/3.1 mm in varus, 2.0/3.4 mm in neutral, 1.8/4.3 mm in valgus, p < 0.01 and 0.01, respectively) between MAA groups, except for the tibial slope angle (9.7° in varus, 10.1° in neutral, 9.8° in valgus, p = 0.31). CONCLUSION: Varus alignment was paradoxically shown in approximately one-third of those with end-stage lateral knee OA on both-leg standing hip-knee-ankle radiographs. Films taken in full extension underreported the degree of OA radiographic severity. LEVEL OF EVIDENCE: Level IV, observational study.

Standardized standing pelvis-to-floor photographs for the assessment of lower-extremity alignment.

OBJECTIVES: The objective of this cross-sectional study was to assess the intra-rater, inter-rater and test-retest reliability and concurrent validity of lower-extremity alignment estimated from a photograph [photographic alignment (PA) angle]. METHODS: A convenience sample of participants was recruited from the community. Radiopaque stickers were placed over participants' anterior superior iliac spines. One radiograph and one photograph were taken with the participant standing in a standardized position. The stickers were removed. After 30 min they were reapplied and a second photograph was taken. The hip-knee-ankle (HKA) angle was measured from each radiograph using customized imaging analysis software. The same software was used by three readers to measure the PA angle from each photograph from the first set twice, at least 2 weeks apart. One reader measured the PA angle from the second set of photographs. Reliability was tested using intraclass correlation coefficients (ICC(2,1)), Bland-Altman analyses and the minimal detectable change (MDC95). Concurrent validity was tested using a Pearson's correlation coefficient and Bland-Altman analysis. RESULTS: Fifty adults participated (mean age 41.8 years; mean body mass index 24.7 kg/m(2)). The PA angle was 4.5° more varus than the HKA angle; these measures were highly correlated (r = 0.92). Intra-rater (ICC(2,1) > 0.985), inter-rater (ICC(2,1) = 0.988) and test-retest reliability (ICC(2,1) = 0.903) showed negligible bias (<0.20°). The MDC95 was 2.69°. CONCLUSIONS: The PA angle may be used in place of the HKA angle if a bias of 4.5° is added. A difference of 3° between baseline and follow-up would be considered a true difference.

Computed tomography scanogram compared to long leg radiograph for determining axial knee alignment.

BACKGROUND AND PURPOSE: Supine computed tomography scanogram (CTS) is a commonly used alternative to weight bearing long leg plain radiograph (LLR) in measuring knee alignment. No published studies have validated its use in the native knee and the post-unicompartmental replacement knee (UKR). We quantified the difference in measurements obtained from CTS and LLR for knee alignment. PATIENTS AND METHODS: Supine CT scanograms and weight bearing long leg plain anteroposterior radiographs were obtained for 40 knees (in 25 patients), 17 of which were native, and 23 of which were post-UKR. The mechanical and anatomical axes of the tibio-femoral joint were measured. Bland-Altman plots were used to calculate the 1.96 standard deviation limits of agreement between CTS and LLR. Intraclass correlation was used to assess intra-rater and inter-rater reliability (where values > 0.81 indicate very good reliability). RESULTS: CTS and LLR were equally reliable in measurement of the mechanical and anatomical axes of the tibio-femoral joint (intraclass correlation coefficient (ICC) > 0.9 for all parameters). Statistically significant and clinically relevant differences were found between CTS and LLR in measurement of the mechanical axis (limits of agreement: UKR -3.2° to 6.3°; native -3.2° to 5.6°) and the anatomical axis (limits of agreement: UKR -3.7° to 8.7°; native -2.0° to 8.8°). INTERPRETATION: Although it is a reliable tool, CTS is not necessarily an accurate one for measurement of knee alignment when compared to LLR. We recommend that CTS should not be used as a substitute for LLR in measurement of the mechanical or anatomical axes of the knee.

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.

Patient-specific instrumentation for total knee arthroplasty does not match the pre-operative plan as assessed by intra-operative computer-assisted navigation.

PURPOSE: The introduction of patient-specific instruments (PSI) for guiding bone cuts could increase the incidence of malalignment in primary total knee arthroplasty. The purpose of this study was to assess the agreement between one type of patient-specific instrumentation (Zimmer PSI) and the pre-operative plan with respect to bone cuts and component alignment during TKR using imageless computer navigation. METHODS: A consecutive series of 30 femoral and tibial guides were assessed in-theatre by the same surgeon using computer navigation. Following surgical exposure, the PSI cutting guides were placed on the joint surface and alignment assessed using the navigation tracker. The difference between in-theatre data and the pre-operative plan was recorded and analysed. RESULTS: The error between in-theatre measurements and pre-operative plan for the femoral and tibial components exceeded 3° for 3 and 17% of the sample, respectively, while the error for total coronal alignment exceeded 3° for 27% of the sample. CONCLUSION: The present results indicate that alignment with Zimmer PSI cutting blocks, assessed by imageless navigation, does not match the pre-operative plan in a proportion of cases. To prevent unnecessary increases in the incidence of malalignment in primary TKR, it is recommended that these devices should not be used without objective verification of alignment, either in real-time or with post-operative imaging. Further work is required to identify the source of discrepancies and validate these devices prior to routine use. LEVEL OF EVIDENCE: II.

Findings related to rotational malalignment in tibial fractures treated with reamed intramedullary nailing.

INTRODUCTION: Rotational malalignment following closed intramedullary nailing of tibial fractures does not attract attention but is a complication which may lead to serious results. This study aimed to present findings related to rotational malalignment from rotational alignment measurements made clinically and with computerised tomography (CT) in patients who had undergone locked intramedullary nailing for tibial fracture. MATERIALS AND METHODS: A total of 26 patients (male/female: 23/3) were evaluated after application of reamed locking intramedullary nailing to a diagnosed tibial shaft fracture. The mean age was determined as 37.5 ± 15.6 years. Rotational alignment was measured in both lower extremities clinically as thigh-foot angle (TFA) and radiologically with CT. Rotational malalignment was accepted as a more than 10º difference between the two lower extremities. RESULTS: Malrotation was determined at more than 10º from TFA in two (7 %) of 26 patients and from CT in five (19 %) of 26 patients. In three of them, the malrotation was >15º. Of the patients determined with malrotation with CT, it was determined from clinical measurements in 40 %. The mean rotational difference was determined as greater with CT measurement (4.7° ± 9.5) compared to the TFA (1.1° ± 5.6) (p < 0.001). No statistically significant relationship was determined between a rotational difference over 10º and the AO fracture type, fracture location and fibula fixation. CONCLUSIONS: A significant number of patients treated with intramedullary nailing for a tibial fracture may result in rotational malalignment. To determine rotational malalignment, a thorough clinical evaluation must be made and different kinds of clinical measurements taken and, when suspicions remain, determination should be made by CT.

[Angular and torsional malalignments of the paediatric knee joint]. / Achsen- und Drehfehler des kindlichen Kniegelenks.

BACKGROUND: Abnormal angular and torsional alignment of the lower extremities during growth are a common reason for consultation of a paediatrician or orthopaedist. There is often uncertainty about the pathological value of these abnormalities and the need for treatment, even among specialists. In the course of physiological growth and development processes, the axial and torsional alignment of the legs sometimes change considerably and in characteristic patterns. DIAGNOSTICS: The ability to assess whether abnormal angular or torsional alignments of the lower limb in the course of growth should still be regarded as normal or already as pathological, depending on age and gender, is essential for the treating physician and requires precise knowledge of the physiological development processes and the tolerable limits in all three spatial dimensions. TREATMENT: After careful explanation to the frequently concerned parents, a restrictive approach with observation of the spontaneous course of correction on the basis of regular clinical check-ups makes sense in the majority of cases. Pathological deviations from the physiological conditions are rare overall, can be idiopathic or of secondary origin and should be further clarified diagnostically using imaging procedures. As conservative measures are ineffective, pronounced angular and/or torsional deformities of the legs requiring treatment can only be corrected by surgical intervention, even in children and adolescents. The surgical treatment modalities available are varied and differ in terms of their invasiveness and complication profile, depending on the localization, type and severity of the deformity, as well as the age and possible concomitant diseases of the affected child or adolescent.