Radiological Alignment Research Articles

“Locked” Scapholunate Instability Diagnosed with 4D Computed Tomography Scan

Background Scapholunate instability (SLI) has a wide range of clinical and radiological presentations. The management depends on the stage of the disorder. Subluxation of scaphoid is pathognomonic feature of the SLI. We describe a patient with SLI with a dislocated proximal pole of scaphoid, out of the distal radius scaphoid fossa. The 4D (three-dimensions + time) computed tomography (CT) scan demonstrated that the scaphoid did not reduce throughout wrist motion. Case Description A 20-year-old male presented with SLI following a fall skateboarding. The 4D CT scan revealed the dislocated scaphoid that did not reduce with wrist motion. He underwent open reduction of the proximal pole of scaphoid and SL reconstruction using flexor carpi radialis (FCR) tendon graft with the Quad tenodesis technique. At 1 year, he had improved pain, wrist functions, and maintained satisfactory radiological alignment. Literature Review We are not aware of any previous description of the dorsal scaphoid dislocation in association with scapolunate instability. Clinical Relevance We recommend that the SLI staging classification needs to be expanded to include dislocation (locked) stage. The 4D CT has a significant role in identifying the instability and its reducibility. Level of Evidence This is a level V study.

PROMS and Radiological Outcomes in Mobile Bearing Total Ankle Arthroplasty for Patients with Varus or Valgus Deformity

Category: Ankle Arthritis Introduction/Purpose: There is increasing evidence that outcomes for total ankle arthroplasty (TAA) are not adversely affected by pre-operative varus deformity. There is a sparsity of evidence relating to outcomes in valgus ankle arthritis. We present our outcomes using a mobile bearing prosthesis (Mobility TAA system, DePuy, Raynham, Massachusetts, USA) with a comparison of neutral, varus and valgus ankles. Methods: This is a single surgeon, retrospective cohort study of consecutive cases. Cases were identified from a locally held joint registry which routinely records PROMS data pre-operatively and at annual intervals. Patients undergoing primary TAA between March 2006 and June 2014 were included. Rrevision procedures along with those with inadequate radiographic images for deformity analysis were excluded. Patients with inadequate PROMS data were included in the radiological analysis but not the PROMS analysis. Data collected included FAOS (Womac Pain, Function and Stiffness), SF-36 scores and patient satisfaction. Radiological data was gathered from routinely taken AP weight bearing radiographs pre-operatively, immediately post-operatively and at final follow up. Pre-operative deformity was measured between the tibial anatomical axis and a line perpendicular to the talus. Patients were classified as neutral, varus (≥10 degrees varus) or valgus (≥10 degrees valgus). Results: 230 cases (see image) underwent radiological classification (152 neutral, 60 varus, 18 valgus) and were included in the radiological analysis (mean follow-up 55.9 months). 164 cases were included in the PROMS analysis (mean follow-up 61.6 months). The groups were similar with regards to BMI and length of follow-up but neutral ankles were younger (P<0.001). Baseline scores were equal except physical health with valgus ankles scoring lowest (P=0.045). Valgus ankles had statistically better post-operative pain (P=0.0247) and function (P=0.012) than neutral ankles. Pre to post-operative change did not reach statistical significance except physical health where valgus outperformed neutral and varus (p=0.039). Mean post-operative angle was 3.1 and final angle 3.7 with no significant differences. There was no significant differences in revision rates. Conclusion: Our study confirms previous evidence that varus deformity does not affect outcome in TAA. Contrary to this, valgus ankles in our cohort performed better post-operatively than neutral ankles. Post-operative coronal radiological alignment was not affected by pre-operative deformity and was maintained over a number of years. Coronal plane deformity does not negatively impact either radiological or clinical outcomes in TAA should not be considered an absolute contra-indication.

No Difference Between a Closing and Opening Wedge High Tibial Osteotomy: 10 Year Results of an RCT

Similar results 10 years after a closing-wedge or opening-wedge HTO in terms of clinical outcome and radiological alignment. Varus deformity increases the risk of progression of medial compartment knee osteoarthritis (OA). Patients with this condition can be treated with a valgus high tibial osteotomy (HTO) with either a closing-wedge or opening-wedge technique. Little is known about the long-term results of closing-wedge versus opening-wedge osteotomy. The aim of this study was to investigate the clinical and radiological long-term results of closing-wedge and opening-wedge HTO. From January 2001 to April 2004, ninety-two patients were randomized to receive either a closing-wedge or an opening-wedge high tibial osteotomy. The clinical outcome and radiographic results were examined preoperatively, at one year, six years, and, for the present study, at ten years postoperatively. The outcomes that we reviewed included maintenance of the achieved correction, progression of osteoarthritis (based on the Kellgren and Lawrence classification), severity of pain (as assessed on a numeric rating scalevisual [NRS]), knee function (as measured with the Hospital for Special Surgery [HSS] score and Knee injury and Osteoarthritis Outcome Score [KOOS]), walking distance, complications, and survival with conversion to a total knee arthroplasty as the end point. The results were analyzed on the basis of the intention-to-treat principle. Out of the original 92 patients included 79 completed 10-year follow-up (52 all measurements, 3 only questionnaires, and 24 TKA), 13 patients were lost to follow-up (6 deceased, 5 emigrated, and 2 unwilling to participate). Sixteen (36%) patients in the closing-wedge and eight (22%) in the opening-wedge group were converted to a TKA after ten years (p = 0.15). Ten years post-operatively, the mean hip-knee-ankle (HKA) angle was 1.5° (± 4.0° SD) of valgus after a closing-wedge HTO and 0.8° (± 5.9° SD) of varus after an opening-wedge HTO (p= 0.276). The mean difference was 2.3° (CI 95%: -0.6 – 5.1), with no statistical significant difference (p=0.12). In both groups the 10-year post-operative HKA-angles did not differ from the one- and six-year post-operative angles. No difference in severity of pain or knee function was found between the two groups. The mean NRS-pain was 2.6 (± 2.8 SD) during rest and 3.7 (± 3.1 SD) during activity in the closing-wedge group. The mean NRS-pain was 2.9 (± 3.0 SD) during rest and 4.1 (± 3.1 SD) during activity in the opening-wedge group. No difference in pain (rest or activity) was found between the groups. The mean HSS was 82.2 (± 13.6 SD) in the closing-wedge group. The mean HSS was 78.6 (± 13.0 SD) in the opening-wedge group. No difference in function was found between the groups. Of the patients who had no conversion to a TKA, no difference in clinical outcome and radiological alignment was seen 10-years post-operatively between the closing-wedge and opening-wedge HTOs. In our six-year follow-up closing-wedge HTO was associated with more conversions to a TKA. This is in contrast to the results of our new results at ten-year follow-up of the same cohort.

Effect of Preoperative Deformity on Arthroscopic and Open Ankle Fusion Outcomes.

Coronal deformity is considered a relative contraindication for arthroscopic ankle fusion. This study assessed whether preoperative coronal ankle joint deformity influenced the outcome of arthroscopic ankle fusion. Ninety-seven patients had 62 arthroscopic and 35 open ankle fusions between 2005 and 2012. Clinical outcomes were prospectively recorded with use of the Ankle Osteoarthritis Scale (AOS) and Ankle Arthritis Scale (AAS) preoperatively and at 6, 12, and 24 months and final follow-up. Radiological alignment was measured using the tibiotalar angle, the tibial plafond angle, the lateral talar station, and the lateral tibiotalar angle. Both groups had the same demographics. Preoperative deformity was the same regarding sagittal alignment and overall coronal alignment, but the arthroscopic group had less tibial deformity (tibial plafond angle range 0-19 degrees vs 0-43 degrees). At final follow-up, the mean AOS was 34.2 for arthroscopic (95% confidence interval [CI], 23.3-45.2) vs 33.9 for open (95% CI, 17.8-49.9). The AAS at final follow-up was 26.0 for arthroscopic (95% CI, 21.0-31.0) vs 27.5 for open (95% CI, 19.7-35.2). Both groups had the same tibiotalar angle, lateral talar station, and lateral tibiotalar angle at follow-up. Regression analyses revealed no influence of type of surgery, preoperative deformity, postoperative radiological alignment, age, sex, body mass index, smoking status, etiology of the arthritis, and need for bone grafting on outcome scores (all P > .05). Arthroscopic and open ankle fusion yielded equivalent results for both patient-reported outcome measure and radiographic alignment in patients with coronal and sagittal joint deformity. Patients with higher tibial plafond angles more often underwent open fusion. III, comparative series.

A comparison of short term radiological alignment outcomes of the patient specific and standard instrumentation for primary total knee arthroplasty: A systematic review and meta-analysis

ObjectiveThe aim of this study was to review the radiological alignment outcomes of patient Specific (PS) cutting blocks and Standard Instrumentation in Primary Total Knee Arthroplasty. MethodsWe hypothesized that the use of PS techniques would significantly improve sagittal, coronal and rotational alignment of the prosthesis on short term. We performed a systematic review and a meta-analysis including all the randomised controlled trials (RCT) using PS and standard (ST) total knee arthroplasty to date. ResultsA total of 538 PS TKA and 549 ST TKA were included in the study. Statistical analysis of the outliers for femoral component sagittal, coronal and rotational positioning, tibial component sagittal and coronal positioning and the overall mechanical axis were assessed. We found that there was no significant benefit from using PS instrumentation in primary knee arthroplasty to aid in the positioning of either the tibial or femoral components. Furthermore sagittal plane tibial component positioning was worse in the PS than the traditional ST group. ConclusionOur results suggest that at present PS instrumentation is not superior to ST instrumentation in primary total knee arthroplasty. Level of evidenceLevel 1, Systematic review of therapeutic studies.

Intra articular distal radius fractures and volar plate fixation: a prospective study

<p class="abstract"><strong>Background:</strong> Despite being one of the most common fractures encountered in patients, intra-articular distal radius fractures still pose therapeutic challenge to Orthopaedic surgeons. With the advent of locking plates, the fixation of these fractures has been made better, specifically by fixed angle volar locking plate. This study investigates the efficacy of these plates using volar approach, functional and clinical outcome, in addition to the radiological alignment.</p><p class="abstract"><strong>Methods:</strong> Thirty patients with closed distal radius fractures, with AO TYPE B3, B4, AND C fracture pattern, operated with distal radius plate fixation using volar approach, were included in the study during the period of August 2014 to August 2016. With a minimum follow up of six months, radiological outcome was analysed and functional outcome recorded (Gartland and Werley’s demerit scoring system).<strong></strong></p><p class="abstract"><strong>Results:</strong> With a mean age of 42 years and follow up of six months, the range of movement of the wrist was very satisfactory, and the mean grip strength was 80% of the opposite wrist. Radiological parameters were well‑maintained, and functional parameters by Gartland and Werley showed a significant improvement in most of the patients during the follow‑up period. The complication rate was less and insignificant.</p><p class="abstract"><strong>Conclusions:</strong> Primary volar plate fixation of intraarticular distal radius fracture provides a stable construct that helps in early mobilization, thereby better functional outcomes and minimizes chances of delayed/malunion.</p>

Does new instrumentation improve radiologic alignment of the Oxford® medial unicompartmental knee arthroplasty?

BackgroundA new instrument system has been introduced to improve the accuracy and reproducibility of implant positioning in Oxford® unicompartmental knee arthroplasty (UKA). This study aimed to determine if the new instrumentation could improve postoperative implant positioning and limb alignment, and reduce the occurrence of outliers in Oxford® UKA. MethodsA total of 77 cases of Oxford® UKA with the new instrumentation were included. Individual matching for the conventional instrument group was performed according to age, sex, and body mass index. Postoperative radiological variables, including the hip-knee-ankle angle and the varus/valgus and flexion/extension angles of the femoral and tibial implants, were measured and compared between the new instrumentation group and the conventional group. The outliers in implant positions and postoperative complications were also compared. ResultsNo significant between-group differences were observed in terms of lower limb alignment and tibial implant alignment. However, statistically significant differences were identified in the varus/valgus and flexion/extension angles of the femoral implant (P=0.01 and P<0.001, respectively). More outliers were observed in the flexion/extension angles of the femoral and tibial implants in the new instrumentation group. Eight meniscal bearing dislocations and three lateral compartmental degenerative changes were found in the conventional group, while there were two meniscal bearing dislocations in the new instrumentation group during the study period. ConclusionThe present study did not confirm any benefit of the new instrument system in terms of postoperative limb alignment, positioning of the implant, or reducing outliers beyond the use of the conventional instruments.

Malalignment after minimally invasive plate osteosynthesis in distal femoral fractures

IntroductionAlthough minimally invasive plate osteosynthesis (MIPO) is a preferred operative treatment for fractures of the distal femur, malalignment is a significant concern because of indirect reduction of the fracture. The purpose of this study, therefore, was to evaluate radiologic alignment after MIPO for distal femoral fractures. Patients and methodsOf the 138 patients with fracture of the distal femur who underwent MIPO, we enrolled 51 patients in whom bilateral rotational alignment could be assessed by postoperative computed tomography (CT). The patients included 32 men and 19 women, with a mean age of 54.3 years. Thirteen patients had femoral shaft fractures (according to the AO/OTA classification: 32-A, n=2; 32-B, n=6; 32-C, n=5), whereas 38 patients had distal femoral fractures (33-A, n=7; 33-C, n=31). Coronal and sagittal alignments were assessed using simple radiography, whereas rotational alignment was assessed using CT. According to the difference between the affected and unaffected sides, we divided the patients into satisfactory and unsatisfactory groups (reference point of 8°, using Handolin’s classification). Thereafter, we determined which factors can lead to malalignment, including fracture location (distal femoral shaft fracture or metaphyseal fracture), fracture pattern (simple fracture, n=15; complex fractures, n=36 patients), coronal and sagittal alignments, and combined ipsilateral long bone fractures. ResultsCoronal and sagittal alignment were satisfactory in 96.2% (average, 2.8°) and 98% (average, 2.2°), respectively, whereas the rotational alignment was satisfactory in 56.9% of patients. Leg length discrepancy was satisfactory in 92.3% of the patients (average, 10.9mm). Concerning rotational malalignment, an unsatisfactory result was obtained in 48.6% of subjects with complex fractures and 26.7% of subjects with simple fractures (p=0.114). No significant correlation was noted between the angular deformity in the coronal and sagittal planes and the degree of rotational alignment (p=0.607 and 0.774, respectively). ConclusionsRegardless of the fracture pattern, rotational malalignment may occur at an extremely high rate after MIPO for fractures of the distal femur.

The relationship between radiological alignment of united distal radius fractures and functional and patient-perceived outcomes in elderly patients.

The purpose of this study was to investigate the relationship between radiological alignment and functional outcomes including strength, range of motion (ROM), and disabilities of the arm, shoulder, and hand (DASH) and patient-rated wrist evaluation (PRWE) scores in elderly patients with united distal radius fractures. We reviewed 118 patients (mean age of 76.2 ± 9.5 years, mean follow-up 36.3 ± 17.6 months). Outcome measures included the DASH and PRWE scores, ROM, and grip and pinch strength were measured using a validated mobile hand-held dynamometer. Radial height, radial inclination, ulnar variance, and palmar tilt were measured on standard radiographs. The mean total score for DASH was 4.9 ± 7.4 and 6.9 ± 11 for the PRWE. There were significant differences in ROM for palmar flexion and ulnar deviation between the affected wrist and the normal wrist. Linear regression revealed significant relationships for the following variables: between DASH and radiological palmar tilt, between PRWE and radiological palmar tilt, between grip strength and radial inclination, between grip strength and radial height, and between grip strength and ulnar variance. This study suggests that minor deformities of the distal radius following distal radius fractures treated with either operative or nonoperative treatment are unlikely to be clinically relevant and have no impact on patient perceived outcomes for elderly patients.

Relationships Between Radiographic Pre- and Postoperative Alignment and Patient Perceived Outcomes Following Weber B and C Ankle Fractures

Anatomic reduction of ankle fractures may influence outcomes but the relationships between these 2 variables are still unknown and require further investigation. The purpose of this study was to investigate the relationships between radiologic alignment of surgically treated ankle fractures and functional outcomes. This retrospective study included patients who were surgically treated for Weber B and C ankle fractures. The outcome measures consisted of the Olerud and Molander Ankle Score (OMAS) and the foot and ankle disability measure. Standard radiographs included anteroposterior, lateral, and mortise views of the ankle, both on pre- and postoperatively. Between June 2011 and December 2013, a total of 152 patients were treated for ankle fractures and 76 patients with a mean age of 41.3 ± 17.1 years and a mean follow-up of 39.6 ± 8.9 months were included. There were 45 Weber type B fractures (mean age 43.4 ± 17.8, 28 females, 17 males) and 31 Weber type C fractures (mean age 40.7 ± 17.3, 12 females, 19 males). Linear regression did not reveal any significant relationships with the exception of age. There was a moderate correlation between the OMAS outcome score and age ( r2 = 0.46, P = .01). We found that younger age was a moderate predictor of functional outcome following surgical treatment of ankle fractures. Radiographic alignment using standard non-weight-bearing radiographs and fracture severity did not predict functional outcomes at 24 months postoperatively. Level III, prognostic, retrospective cohort study.

Computer-assisted stereotaxic navigation improves the accuracy of mechanical alignment and component positioning in total knee arthroplasty.

This study reports on a novel computer-assisted stereotaxic navigation (CASN) system that attempts to combine the accuracy of computer navigation with familiarity of conventional methods. We hypothesize that CASN would improve mechanical alignment and component positioning when compared to conventional instrumentation. 145 patients (192 knees) retrospectively matched for age, BMI, gender and pre-operative scores, underwent total knee arthroplasty (TKA) using CASN (n=92) or conventional instrumentation (n=100). Pre- and post-operative radiological alignment [Acceptable ranges: mechanical axis (MA) 0°±3°, coronal femoral-component angle (CFA) and coronal tibia-component angle (CTA) 90°±3°] and clinical outcomes (Knee Society Scores, Oxford Knee Score and Short Form-36) at 6months were examined. The CASN group had significantly improved mean MA (1.9°±1.4°, versus 2.8°±2.0° in the conventional group, p=0.001), CFA (1.6°±1.3°, versus 2.1°±1.5° in the conventional group, p=0.035) and CTA (1.6°±1.2°, versus 2.1°±1.5° in the conventional group, p=0.024). 91.3% of knees in the CASN group were within 3° of a neutral mechanical axis, versus 74% in the conventional group (p<0.001). The duration of surgery was significantly longer in the CASN group (84±22 vs 73±15min, p=0.001) and cost an additional USD 850 per operation. There were no significant differences in clinical outcomes or satisfaction rates at 6months post-operatively (p>0.05). CASN improved TKA mechanical alignment and component positioning, however, resulted in longer and costlier surgery with no benefits in short-term functional outcomes, despite providing familiarity to surgeons accustomed to conventional instrumentation. III.

PSI kinematic versus non-PSI mechanical alignment in total knee arthroplasty: a prospective, randomized study

Kinematic alignment in TKA is supposed to restore function by aligning the components to the premorbid flexion-extension axis instead of altering the joint line and natural kinematic axes of the knee. The purpose of this study was to compare mechanically aligned TKA to kinematic alignment. In this study, 200 patients underwent TKA and were randomly assigned to 2 groups: 100 TKAs were performed using kinematic alignment with custom-made cutting guides in order to complete cruciate-retaining TKA; the other 100 patients underwent TKA that was manually performed using mechanical alignment. The WOMAC and combined Knee Society Score (KSS), as well as radiological alignment, were determined as outcome parameters at the 12-month endpoint. WOMAC and KSS significantly improved in both groups. There was a significant difference in both scores between groups in favour of kinematic alignment. Although the kinematic alignment group demonstrated significantly better overall results, more outliers with poor outcomes were also seen in this group. A correlation between post-operative alignment deviation from the initial plan and poor outcomes was also noted. The most important finding of this study is that applying kinematic alignment in TKA achieves comparable results to mechanical alignment in TKA. This study also shows that restoring the premorbid flexion-extension axis of the knee joint leads to better overall functional results. Kinematic alignment is a favourable technique for TKA. The kinematic alignment idea might be a considerable alternative to mechanical alignment in the future. II.

Absence d’avantage sur l’alignement frontal des prothèses de genou posées avec ancillaire personnalisé : revue systématique et méta-analyse

AimA systematic review and meta-analysis of clinical studies assessing alignment outcomes in patient- specific instrumented (PSI) knee arthroplasty was conducted. Materials and methodsPRISMA compliant data was extracted from literature databases up to January 2014. ResultsTwenty-six studies met the inclusion criteria, reporting a total of 1792 knees. Twenty-three studies reported alignment outcomes in the coronal plane, 11 in the sagittal plane. In all but three series, MRI was the pre-operative imaging modality. Range of mean post-operative alignment (Hip Knee Ankle [HKA] angle) was 176.5 to 181.70. The proportion of three degrees of outliers showed an overall mean of 18.6%. In total, fifteen studies compared alignment outcomes between standard and PSI. From these, four studies showed significantly higher accuracy of coronal plane alignment with PSI (HKAangle). Meta-analysis of seven high-quality comparative studies demonstrated no significant increased accuracy in post-operative mechanical axis (HKAangle) with PSI. Sub-group meta-analysis of both femoral and tibial rotation was not feasible due to a low number of inclusive high-quality series. ConclusionsFurther studies are required to demonstrate both clinical and radiological alignment outcomes in PSI knee arthroplasty with focus upon tibial and femoral rotation. Level of evidence1

No demonstrable benefit for coronal alignment outcomes in PSI knee arthroplasty: A systematic review and meta-analysis

AimA systematic review and meta-analysis of clinical studies assessing alignment outcomes in patient-specific instrumented (PSI) knee arthroplasty was conducted. Materials and methodsPRISMA compliant data was extracted from literature databases up to January 2014. ResultsTwenty-six studies met the inclusion criteria, reporting a total of 1792 knees. Twenty-three studies reported alignment outcomes in the coronal plane, 11 in the sagittal plane. In all but three series, MRI was the preoperative imaging modality. Range of mean postoperative alignment (hip–knee–ankle [HKA] angle) was 176.5 to 181.70. The proportion of three degrees of outliers showed an overall mean of 18.6%. In total, fifteen studies compared alignment outcomes between standard and PSI. From these, four studies showed significantly higher accuracy of coronal plane alignment with PSI (HKA angle). Meta-analysis of seven high-quality comparative studies demonstrated no significant increased accuracy in postoperative mechanical axis (HKA angle) with PSI. Subgroup meta-analysis of both femoral and tibial rotation was not feasible due to a low number of inclusive high-quality series. ConclusionsPSI knee arthroplasty is shown not to confer increased accuracy in reconstituting the postoperative mechanical axis. Further studies are required to demonstrate both clinical and radiological alignment outcomes in PSI knee arthroplasty with focus upon tibial and femoral rotation. Level of evidenceLevel 2 – meta-analysis.

Superior alignment but no difference in clinical outcome after minimally invasive computer-assisted unicompartmental knee arthroplasty (MICA-UKA).

Variety of clinical trials have been published comparing the alignment of MICA-UKA with MI-UKA. However, to the best of our knowledge, no published study has showed whether radiological alignment by MICA-UKA has influence on the clinical results. The present study was conducted to compare the short-term results of MICA-UKA with MI-UKA. It was hypothesized that better alignment as well as clinical results was achieved by MICA-UKA as compared to MI-UKA. The clinical and radiological results of 87 subjects who underwent primary UKA using either minimally invasive and computer-assisted technique (45 patients Group A) or minimally invasive technique (42 patients, Group B) were reported. Knee Society scores (KSSs), Knee Society functional scores (KSFSs), range of motion (ROM), and radiographic results were assessed and reported preoperatively and at 24-month follow-up. Total blood loss, operative time, and length of skin incision were compared. The accuracy of the implantations in relation to the coronal mechanical axis in Group A was significantly superior to that of Group B (P=0.033). The femoral rotational profile revealed the prosthesis in Group A that was implanted with significantly less internal rotation than Group B (P=0.025). Clinical results, with regard to ROMs and KSSs, as well as KSFSs were equally good in both the groups. The average blood loss in patients of Group A was significantly reduced as compared to patients of Group B. No significant difference was detected in terms of operative time or length of skin incision. It is suggested that MICA-UKA improves the implant alignment without increasing clinical results versus MI-UKA. We advocate that computer navigation should be considered when minimally invasive unicompartmental knee arthroplasty is performed. Therapeutic study, Level II.

Better survival of valgus opening-wedge high tibial osteotomy: 10-year results of a RCT comparing closing wedge and opening wedge technique

s / Osteoarthritis and Cartilage 22 (2014) S57–S489 S468 855 BETTER SURVIVAL OF VALGUS OPENING-WEDGE HIGH TIBIAL OSTEOTOMY: 10-YEAR RESULTS OF A RCT COMPARING CLOSING WEDGE AND OPENING WEDGE TECHNIQUE T. Duivenvoorden y, R. Brouwer z, K. Bos y, M. Reijman y, S. Bierma Zeinstra y, J. Verhaar y. y Erasmus Univ. Med. Ctr., Rotterdam, Netherlands; zMartini Hosp., Groningen, Netherlands Background: Varus deformity increases the risk of progression of medial compartment knee osteoarthritis (OA). Patients with this condition can be treated with a valgus high tibial osteotomy (HTO) with a closing-wedge or opening-wedge technique. Little is known about the long-term results of closing-wedge versus opening-wedge osteotomy. Purpose: The aim of this study was to investigate the clinical and radiological long-term results of closing-wedge and opening-wedge HTO. Methods: Between January 2001 and March 2004, 92 patients were randomized to either a closing-wedge or opening-wedge HTO. The clinical outcome and radiological results were examined pre-operatively, at one year, six years, and, for the present study, at ten years post-operatively. Our outcomes included the endurance of achieved correction, progression of OA (Kellgren & Lawrence), severity of pain (visual analogue scale and Intermittent and Constant OsteoArthritis Pain score), knee function (Hospital for Special Surgery score, Knee Injury and Osteoarthritis Outcome Score), walking distance, complications and survival.We defined the non-survivors in our survival analysis as “patients converted to a total knee arthroplasty (TKA)” or as “patients in need for a TKA” according to the OARSI-criteria. The results were analyzed on basis of the intention to treat principle. The provisional ten year follow-up results are presented in this abstract. Results: In the meantime 80 of the 92 patients are analysed 10 years post-operatively. Until March 2014 the remaining 12 patients will be invited to visit the outpatient clinic to ensure a minimal follow-up of 10 years. Twelve (39%) patients in the closing-wedge and six (18%) in the opening-wedge group were converted to a TKA after ten years (p < 0.05). Eighteen (58%) patients in the closing-wedge and 15 (44%) patients in the opening-wedge group were in need for a TKA after 10 years (p 1⁄4 0.26). Ten years post-operatively, the hip-knee-ankle (HKA) angle was 0.1 ( 5.0 SD) of valgus after a closing-wedge HTO and 2.4 ( 6.9 SD) of valgus after an opening-wedge HTO (p 1⁄4 0.276). In both groups the 10-year post operative HKA-angles did not differ from the oneand six-year post-operative angles. No difference in severity of pain or knee function was found between the two groups. Four (9%) complications occurred in the closing-wedge and 17 (37%) in the opening-wedge group. Conclusions: Of the patients who had no conversion to a TKA, no difference in clinical outcome and radiological alignment was seen 10years post-operatively between the closing-wedge and opening-wedge HTOs. In the present study, opening-wedge HTO was found to be associated with more complications. Closing-wedge HTO was associated with more conversions to a TKA, however no difference in number of patients in need for a TKA was found. 856 HIP RESURFACING VERSUS TOTAL HIP ARTHROPLASTY IN PATIENTS WITH HIP OSTEOARTHRITIS: COMPARING STANDARDIZED OUTCOMES K.V. MacDonald y, C. Frank z, T. Noseworthy x, D. Lorenzetti y, J. Werle y, T. Wasylak k, D. Dick k, G. O’Connor {, D.A. Marshall y. yUniv. of Calgary, Calgary, AB, Canada; zAlberta Innovates Hlth.Solutions, Calgary, AB, Canada; xAlberta Hlth.Services; Univ. of Calgary, Calgary, AB, Canada; kAlberta Hlth.Services, Calgary, AB, canazda; {Univ. of Alberta, Calgary,

Functional outcomes following total knee arthroplasty: A randomised trial comparing computer-assisted surgery with conventional techniques

BackgroundA number of trials have shown improved radiological alignment following total knee arthroplasty using computer-assisted surgery (CAS) compared with conventional surgery. Few studies, however, have looked at functional outcomes. MethodsWe prospectively studied a cohort of 107 patients that underwent TKA by a single surgeon. Patients were randomised into 3 groups: computer-assisted surgery for both the femur and the tibia, intramedullary guides for both the femur and the tibia, and an intramedullary guide for the femur and an extramedullary guide for the tibia.Patients were followed-up post-operatively with the Short Form Health Survey (SF-12) and Oxford Knee Score (OKS) questionnaires. ResultsAt a median follow-up of 46months (range 30-69months), there was a trend towards higher OKS results in the CAS group, with a mean score of 40.6 in the CAS group compared to 37.6 in the extramedullary group and 36.8 in the intramedullary group. The difference seen in the OKS between CAS and the conventional groups had a significant unadjusted p-value (0.024), and approached significance when adjusted for age and sex (0.054). There was a significant improvement in the OKS when the mechanical axis was within ±3° of neutral, versus those outside this range (median of 41.0 compared to 38.3, p=0.045). DiscussionThis study shows that clinically significant differences are being seen in functional scores of patients treated with CAS versus conventional guides, at medium-term follow up. Our findings reinforce the tenet that a coronal mechanical axis of within 3° of neutral equates to significantly better functional outcomes.

Does patella position influence ligament balancing in total knee arthroplasty?

In vivo comparative gap measurements were performed in three different patella positions (reduced, subluxated and everted) using offset-type-force-controlled-spreader-system. Prospectively, 50 knees were operated by total knee arthroplasty using a navigation-assisted gap-balancing technique. The offset-type-force-controlled-spreader-system was used for gap measurements. This commercially available instrument allows controllable tension in patella-reduced position. The mediolateral gaps of knee extension (0°) and flexion (90°) angle were recorded in three different patella positions; reduced, subluxated and everted. Any gap differences of more than 3 mm were considered as a meaningful difference. Correlation between the difference with the demographic data, preoperative radiologic alignment and intraoperative data was analysed. For statistical analysis, ANOVA and Pearson's correlation test were used. The gaps in patella eversion demonstrated smaller gaps both in knee extension and flexion position compared to the gaps of patella reduction position. The amount of decreased gaps was more definite in knee flexion position. Statistically significant difference was observed for the lateral gap of patella eversion compared to gap of patella reduction in knee flexion position (p < 0.05). There were notable cases of variability in knee flexion position. Significant portion of 12 (24 %) knees of patella subluxation and 33 (66 %) knees of patella evertion demonstrated either increased or decreased gaps in knee flexion position compared to the gaps of patella reduction position. The gaps in patella eversion demonstrated smaller gaps both in knee extension and flexion position compared to the gaps of patella reduction position. The amount of decreased gaps was more definite in knee flexion position. Therefore, the intraoperative patellar positioning has influence on the measurement of the joint gap. Keeping the patella in reduced position is important during gap balancing. I.

Reconstruction with expandable cages after single- and multilevel corpectomies for spinal metastases: a prospective case series of 60 patients

Background contextExpandable cages are widely used to reconstruct the spine after the removal of vertebral metastases. Long-term results, however, are lacking, and there is little information on reconstruction after multilevel corpectomies. PurposeTo determine long-term outcome for reconstruction of the spine with expandable cages after single and multilevel corpectomies for spinal metastases. Study designA prospective cohort study of 60 consecutive patients with spinal metastases treated with expandable cages. MethodsAll patients were prospectively followed with regular clinical and radiographic evaluation. Outcome measures were the Frankel score, patients' self-reported recovery, radiological alignment of the spine, and neurologic plus biomechanical complications. ResultsSixty patients were treated with expandable cages in our hospital in a 5-year period with a maximum follow-up of 6 years. Single-level reconstruction was performed in 48 cases, 2-level in 8, and 3-level in 4. Postoperatively, the Frankel score had improved significantly (p=.03), the segment height had increased (p=.02), and, in severe cases of kyphosis (>20°), the regional angulation had been corrected compared with preoperatively (p<.001). Complication rate, however, was high (36.7%), in particular after multilevel reconstruction, in which three cases had to be reoperated years after the initial surgery; reasons for this were hardware failure, progressive kyphosis, and bronchial perforation. Good recovery was reported in 70% of all patients. ConclusionsExpandable cages can be used successfully in reconstruction of the spine after single and multilevel corpectomies for spinal metastases. However, long-term complication rate is high. Promotion of bony fusion, prevention of soft-tissue damage, adequate posterior stabilization, and careful patient selection may reduce these complications.

The minimally invasive far medial subvastus approach for total knee arthroplasty in valgus knees

The lateral approach in the valgus knee asks for a lot of soft tissue releases during the arthrotomy. The hypothesis of this study was that the far medial subvastus approach could be used in valgus knees and would guarantee both functional and radiological good to excellent results. This is a retrospective study on 78 patients (84 knees) undergoing primary total knee arthroplasty (TKA) for type I or II fixed valgus knees. The mean (SD) preoperative mechanical alignment was 187° (4°) HKA angle. Functional recovery, pain, tourniquet times, necessary soft tissue releases as well as radiological alignment were measured. The Knee Score improved significantly from 45 (10) to 90 (10) (P < 0.05) and the function score improved as well from 35 (20) to 85 (10) (P < 0.05). Flexion improved from 110° (10°) to 137° (8°). Hospital stay was 4 (1.2) days. Alignment was corrected to 181° (1.5°) HKA angle with a postoperative joint line shift of +2.8 (3.2) mm. No clinical instability, as evaluated by the senior author, or osteolytic lines was observed at minimal one-year radiological follow-up. The far medial subvastus approach is an excellent approach to perform Krackow type I and II TKA with primary PS implants.