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Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_II | Pages 133 - 133
1 Jul 2002
Bevan W Jamieson EJ
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Aim: This study was performed to review the early results of the use of a semi-constrained acetabular component in the treatment of recurrent hip dislocation at Palmerston North Hospital. Method: A retrospective case study of patients who underwent acetabular component revision with a semi-constrained cup for recurrent dislocation of the hip was performed. Results: Between April 1999 and July 2000, 10 patients with an average age of 75 years underwent acetabulum revision with a semi-constrained cup. There was an average of four dislocations before revision surgery, per patient. At follow-up between three and 18 months after the revision, there had been no dislocations. Aggressive post-operative rehabilitation was permitted, allowing discharge at an average of seven days postoperatively. Conclusion: The use of a semi-constrained acetabular cup was successful as a means of treatment for recurrent hip dislocation. This is an early review of the use of the implant. There are no published data on long term survival of this implant. The semi-constrained cup provides a simple yet effective option for dealing with the elderly recurrent hip dislocation


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_4 | Pages 36 - 36
1 Jan 2016
Sumino T Saito S Ishii T
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Introduction. The Flexible Nichidai Knee (FNK) System (Nakashima Medical, Japan) was designed to fit Asian knees. Especially, the posterior stabilized(PS) prosthesis was designed as semi-constrained posterior stabilized system that had a large tibial post and femoral articulation. We hypothesized that the semi-constrained PS implant design would have a positive influence on vivo kinematics after total knee arthroplasty (TKA). Materials and Methods. A total of 16 patients (21 knees) who had undergone TKA using PS implant were randomly recruited from our database. Of the 16 patients, all patients were women. Fourteen patients had osteoarthritis and 2 patients had rheumatoid arthritis. The average age was 72.3± 9.5 years, and the average postoperative duration was 23.4 ± 19.3 months. The subject performed sequential deep knee bends under WB from 0° to maximum flexion under fluoroscopic monitoring in the sagittal plane. Conversely, under NWB, the patient sat on a chair and was asked to perform active assisted knee flexion. To estimate spatial position and orientation of the artificial knee prosthesis, a 2D to 3D registration technique was used. We evaluated knee range of motion, femoral axial rotation relative to the tibial component, and anteroposterior translation of the femorotibial contact point for both medial and lateral sides. Closest distances between femoral cam and tibial post engagement were measured,. Results. Range of Motion. The mean full extension angle between femoral and tibial components, was −8.1±8.8°and −7.5±5.5°in WB and NWB, respectively. The mean maximum-flexion angle was 110.0±18.1°and 119.3±8.9°in WB and NWB, respectively. Femoral Axial Rotation. Fig.1 shows the mean degree of femoral axial rotation relative to the tibial components in WB and NWB. The femur was externally rotated 0.7±3.9°and 0.3±4.7°at 0° degree in WB and NWB, respectively. The external rotation increased to 4.8±5.2°and 6.2±5.9°at 120°flexion in WB and NWB, respectively. Anteroposterior Translation. The mean femorotibial contact point under WB and NWB was shown in Fig.2 for medial contact and Fig. 3 for lateral contact. Under WB, the mean medial contact point moved posteriorly from −1.6±2.0mm at 0° flexion. The point then moved gradually anteriorly with flexion to −9.3±1.5mm at 120°flexion. The mean lateral contact point moved posteriorly from −1.9±1.7mm at 0° flexion, and then moved anteriorly to at −8.9±2.7mm 120° flexion. Under NWB conditions, the mean medial contact point moved posteriorly from −1.1±1.8mm at 0° flexion. The point then moved gradually posteriorly with flexion to −6.6±2.8mm at 120° flexion. The mean lateral contact point in PS TKA moved posteriorly from −4.4±3.3mm at 0° flexion, and then moved posteriorly to −12.3±3.6mm at 120°flexion. Post-Cam Engagement. The mean knee flexion angle at initial post-cam engagement was 61.9 ± 15.9° under WB and 57.5 ± 16.0° under NWB. Discussion. Our study showed external rotation and bycondylar posterior rollback pattern in the entire range of knee flexion. The reason for this might be that the post cam design was high(20mm), which does not allow for high external rotation. The in vivo kinematics of the semi-constrained PS FNK prosthesis showed similar kinematic patterns due to the development concept of the implant design


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 340 - 340
1 Jul 2011
Ignatiadis I Arapoglou D Pateromihelakis E Psyllakis P Hatzinikolaou N Pananis E Gerostathopoulos N
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To show the role and effectiveness of semi-constrained total elbow arthroplasty in restoring elbow function in severe, irreversible post-traumatic osseous and chondral injuries. Eighteen patients, aged 19–80, 11 male and 7 female, suffering from serious, irreversible anatomical and functional lesions of the elbow joint due to previous severe untreated or inadequately treated fractures (T-type transcondylar, trochlear-condylar, open fxs with large bony defects, severe osteochondral, heterotopic ossification in ICU fracture patients). Postop follow up was 9–57 months. All patients were treated with modular, cemented, semi-constrained linked total elbow arthroplasty. A functional brace was used post-operatively, and motion was permitted on the 3rd post-op day. The patients were allowed a full range of motion at 1 week post-op and they were subjected to vigorous physiotherapy. Post-op results were evaluated by using Mayo, DASH, quick-DASH scores and measuring grip strength and range of motion. Our results ranged from satisfactory to excellent in 16 patiens, with good strength and wide motion arc (with up to 15o extension-flexion deficit). One old female patient suffered a severe cerebral stroke with a bad outcome. In another young male patient the motion arc reached only 40% of the normal (spasticity, ICU patient with brain injury). Semi-constrained linked total elbow arthroplasty proves to be an effective method of treatment in severe, irreversible, intraarticular post-traumatic elbow injuries with chondral destruction and grave functional deficit, provided the proper technique is employed and a vigorous rehabilitation program is followed


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_16 | Pages 40 - 40
1 Oct 2016
Hamilton D Simpson P Patton J Howie C Burnett R
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Patient function is poorly characterised following revision TKA. Modern semi-constrained implants are suggested to offer high levels of function, however, data is lacking to justify this claim. 52 consecutive aseptic revision TKA procedures performed at a single centre were prospectively evaluated; all were revision of a primary implant to a Triathlon total stabiliser prosthesis. Patients were assessed pre-operatively and at 6, 26, 52 and 104 weeks post-op. Outcome assessments were the Oxford Knee Score (OKS), range of motion, pain rating scale and timed functional assessment battery. Analysis was by repeated measures ANOVA with post-hoc Tukey HSD 95% simultaneous confidence intervals as pairwise comparison. Secondary analysis compared the results of this revision cohort to previously reported primary TKA data, performed by the same surgeons, with identical outcome assessments at equivalent time points. Mean age was 73.23 (SD 10.41) years, 57% were male. Mean time since index surgery was 9.03 (SD 5.6) years. 3 patients were lost to follow-up. All outcome parameters improved significantly over time (p <0.001). Post-hoc analysis demonstrated that all outcomes changed between pre-op, 6 week and 26 weeks post-op assessments. No difference was seen between primary and revision cohorts in OKS (p = 0.2) or pain scores (p=0.19). Range of motion and functional performance was different between groups over the 2 year period (p=0.03), however this was due to differing pre-operative scores, post-hoc analysis showed no difference between groups at any post-operative time point. Patients undergoing aseptic revision TKA with semi-constrained implants made substantial improvements in OKS, pain scores, knee flexion, and timed functional performance, with the outcomes achieved comparable to those of primary TKA. High levels of function can be achieved following revision knee arthroplasty, which may be important considering the changing need for, and demographics of, revision surgery


The Journal of Bone & Joint Surgery British Volume
Vol. 74-B, Issue 2 | Pages 297 - 299
1 Mar 1992
O'Driscoll S An K Korinek S Morrey B

We used 11 cadaver elbows and a three-dimensional electromagnetic tracking device to record elbow movements before and after implantation of a 'loose-hinged' elbow prosthesis (modified Coonrad). During simulated active motion there was a maximum of 2.7 degrees (+/- 1.5 degrees) varus/valgus laxity in the cadaver joints. This increased slightly after total elbow arthroplasty to 3.8 degrees (+/- 1.4 degrees). These values are lower than those recorded for the cadaver joints and for the prostheses at the limits of their varus/valgus displacements, indicating that both behave as 'semi-constrained' joints under physiological conditions. They suggest that the muscles absorb some of the forces and moments that in a constrained prosthesis would be transferred to the prosthesis-bone interface


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 460 - 460
1 Sep 2009
Zollinger PE Tuinebreijer WE Ünal H Ellis ML
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Osteoarthritis of the trapeziometacarpal joint can be treated by different surgical procedures. These are known to lead to complications, complex regional pain syndrome (CRPS) type I being one of them. We investigated prospectively our clinical results after total joint arthroplasty under vitamin C prophylaxis. Patients with trapeziometacarpal joint arthritis stage II or III (according to Dell) underwent joint arthroplasty. Visual analogue scale (VAS) scores for pain, activities of daily living (ADL), satisfaction and first web opening were taken pre- and postoperatively. Vitamin C 500 mg daily was started two days prior to surgery during 50 days as prophylaxis for CRPS. Postoperative treatment consisted of a bandage with collar and cuff for 5 days. Follow-up was at 2 and 6 weeks, 6 months and 12 months (with check radiographs). We performed 34 arthroplasties in 29 patients (23 females and 6 males) with a mean follow-up of 39 months. Mean age was 61 years. The degree of osteoarthritis according to Dell was stage II in 13 cases, stage III 20 times and in one case there was a traumatic trapeziometacarpal dislocation. Operation was performed in day care under general or regional anesthesia. We implanted a hydroxy-apatite coated, semi-constrained prosthesis, type Roseland (total trapeziometacarpal joint prosthesis; Depuy International Ltd, Leeds, England). First web opening increased with 18 degrees and there was a significant improvement for pain, ADL and satisfaction as well (p = 0.000). There were no signs of loosening of the prosthesis, no infections and no cases of CRPS. In this study the postoperative treatment was completely functional. The semi-constrained design of the Roseland prosthesis doesn’t require immobilisation. Torrededia reported 5 patients with CRPS after 38 operations with this same implant (13%). The positive trend in preventing CRPS gives us enough arguments to further investigate this in the form of a RCT


The Bone & Joint Journal
Vol. 96-B, Issue 10 | Pages 1359 - 1365
1 Oct 2014
Large R Tambe A Cresswell T Espag M Clark DI

Medium-term results of the Discovery elbow replacement are presented. We reviewed 51 consecutive primary Discovery total elbow replacements (TERs) implanted in 48 patients. The mean age of the patients was 69.2 years (49 to 92), there were 19 males and 32 females (37%:63%) The mean follow-up was 40.6 months (24 to 69). A total of six patients were lost to follow-up. Statistically significant improvements in range movement and Oxford Elbow Score were found (p < 0.001). Radiolucent lines were much more common in, and aseptic loosening was exclusive to, the humeral component. Kaplan–Meier survivorship at five years was 92.2% (95% CI 74.5% to 96.4%) for aseptic loosening. In four TERs, periprosthetic infection occurred resulting in failure. A statistically significant association between infection and increased BMI was found (p = 0.0268). Triceps failure was more frequent after the Mayo surgical approach and TER performed after previous trauma surgery. No failures of the implant were noted. . Our comparison shows that the Discovery has early clinical results that are similar to other semi-constrained TERs. We found continued radiological surveillance with particular focus on humeral lucency is warranted and has not previously been reported. Despite advances in the design of total elbow replacement prostheses, rates of complication remain high. Cite this article: Bone Joint J 2014;96-B:1359–65


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_I | Pages - 47
1 Mar 2002
Mansat P Head S Rongières M Bellumore Y Bonnevialle P Mansat M
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Purpose: We report our experience with 23 Coonrad-Morrey total elbow prostheses. Material and methods: Between July 1997 and February 2001, we implanted 34 Coonrad-Morrey total elbow pros-theses in 33 patients. Twenty-three patients (23 implants) were reviewed at a mean 24 months follow-up, maximum 40 months. There were three men and 20 women, mean age 62 years (42–69). Twelve patients had rheumatoid polyarthritis, the principal indication. There were also four recent fractures of the distal humerus, two nonunions, and one patient with post-traumatic osteoarthritis. One patient had sequelar osteoarthritis since childhood. Finally three revisions were performed for loosening of a GUEPAR prosthesis in two cases and a GSBIII prosthesis in one. Results were assessed with the Mayo Clinic score. We searched for lucent lines around the implants, polyethylene wear, and incorporation of the bone graft behind the anterior wing of the implant on plain radiographs. Results: At last follow-up, the mean Mayo Clinic score had improved from 25 to 89 points (70–100). Before surgery, 17 patients had severe pain. At last follow-up, eight patients had occasional pain. Extension was improved by 10°, flexion by 27° giving a postoperative amplitude of 29° to 132°. Prona-tion supination progressed by 37° giving a rotation amplitude of 127°. The function score improved from 4 to 21 points. Sixteen of the 23 patients had normal elbow function. Outcome was excellent in 13 patients, good in eight, and fair in two. There were no lucent lines visible on the radiographs. There was no sign of polyethylene wear. The bon graft was incorporated behind the implant in 20 cases and was not visible in three. Complications included one peroperative fracture, one cutaneous dehiscence, one post-operative fracture of the olecranon due to a fall, and persistent ulnar paresthesia in four patients requiring secondary neurolysis in one. Discussion, conclusion: The Coonrad-Morrey semi-constrained prosthesis provides a response to a large range of situations. The dominant indication is rheumatoid polyarthritis, but trauma patients can benefit from this reliable therapeutic solution giving a satisfactory rate of success. A satisfactory functional amplitude is generally achieved with this implant and the elbow is generally pain free


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_IV | Pages 466 - 466
1 Apr 2004
Singh G Jamieson E
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Introduction A review of hip replacements performed in our hospital between 1991 and 2000 has identified a group of post-operative patients in whom recurrent dislocation has been deemed untreatable because of medical comorbidity. We tried to identify a group of patients at risk of recurrent dislocations. This paper presents our experience with the Kasselt cup in these patients. Methods We have used the Kasselt cup with indications being: a) prophylaxis, in patients with perceived greater risk of recurrent dislocation and b) treatment of recurrent (three or more) dislocations following THR. Patients were identified from clinical records and a National Joint Register. From 1998 to 2002, 51 patients underwent THR utilizing semi-constrained Kasselt cup. All living patients were invited for clinical and radiographic examination. Forty-eight patients (51 hips) were available for study. Thirty-nine patients were able to attend clinic and nine were interviewed by telephone. Average follow-up was 18.6 months (range 6 to 36 months). Average age was 75.6 years (range 56 to 92 years). Twenty-nine operations were done prophylactically and 22 for recurrent dislocations. Results Three patients suffered further dislocations, from the recurrent dislocation group. One suffered a single dislocation post-operatively which was reduced by close manipulation and to-date has not re-dislocated. The second continued to dislocate. The third was revised with a Kasselt cup for recurrent dislocation and suffered three further dislocations. This patient was re-revised and to-date (six months) has had no further dislocation. The mean Harris Hip Score in the whole group was 79 (range 49 to 100). We have seen no dislocation in patients in the ‘at risk’ group in this short term. Conclusion The value of this prosthesis remains uncertain


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_III | Pages 202 - 202
1 Mar 2003
Singh G Jamieson E
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A review of total hip replacements (THR) performed in Palmerston North between 1991–2000 has identified a group of postoperative patients in whom recurrent dislocation has been previously deemed untreatable because of medical co-morbidity. From 1998 to 2001, 47 patients underwent THR utilizing a semi-constrained “Kasselt” cup to reduce the risk of dislocation. Indications for use of this cup were: Recurrent dislocation following primary or revision THR (3 or more dislocations) or perceived greater risk of recurrent dislocation eg. elderly, mental confusion, neurological compromise or fracture neck of femur. This paper presents the early results in these 47 patients (49 hips). Clinical records and radiographs of all hip replacement patients were retrospectively reviewed to identify the “Kasselt” group and telephone contact was made for permission to participate in the study. All living patients were sent a self-evaluation questionnaire and invitation to attend clinic for physical examination and radiographs of the hip joint. Twenty-one patients were recurrent dislocators and 24 were at risk patients. Out of 45 living patients 36 were physically examined between 6 and 36 months following surgery. All collected data was statistically analysed using StatWave software. Results: Forty-three of the 45 living patients (47 hips) had no dislocations following surgery. Two patients suffered further dislocation, both of whom were previously recurrent dislocators. One suffered a single dislocation postoperatively which was reduced closed and to date has not re-dislocated. The second continues to dislocate. The mean postoperative Harris Hip Score in the whole group is 79 (range 49–100). Early results reveal no dislocations in the “at risk” primary group


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 2 | Pages 191 - 195
1 Feb 2005
Mighell MA Dunham RC Rommel EA Frankle MA

We present six patients with chronic dislocation of the elbow who were treated by primary semiconstrained total elbow arthroplasty. All were women with a mean age of 65 years (51 to 76), the mean interval between dislocation and surgery was 17 weeks (5 to 52) and the mean follow-up 58 months (24 to 123).

The most dramatic improvement was in function. The mean American Shoulder and Elbow Surgeon score was 5.2 times better (p < 0.001) and the mean total range of movement increased from 33° to 121° (p < 0.001) after operation. Three patients developed wear of polyethylene. One required revision for a periprosthetic fracture, and another required a bushing exchange.

Primary semiconstrained elbow arthroplasty provides significant, predictable functional improvement. Potential solutions for wear of polyethylene include a different operative technique or design of implant. Despite the high incidence of such wear, total elbow arthroplasty should be considered as a viable treatment option for chronic dislocation of the elbow in elderly patients.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_3 | Pages 98 - 98
1 Feb 2017
Dickinson M Shalhoub S Fitzwater F Clary C Maletsky L
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Introduction

Tibiofemoral constraint in patients with total knee replacements (TKR) is dependent on both implant geometry and the surrounding soft tissue structures. Choosing more highly constrained geometries can reduce the contribution of soft tissue necessary to maintain joint stability [1]. Often when knee revision surgeries are required, the soft tissue and bone are compromised leading to the use of more constrained implants to ensure knee stability [2]. The current study quantifies the differences in varus-valgus (VV) and internal-external (IE) constraint between two types of total knee revision systems: SIGMA® TC3© and ATTUNE® REVISION.

Methods

Nine cadaveric knees (7 male, age 64.0 ± 9.8 years, BMI 26.28 ± 4.92) were implanted with both fixed-bearing SIGMA TC3 and ATTUNE REVISION knee systems. Five knees received the TC3 implant first, while the remaining 4 received the ATTUNE implant first. The knees were mounted in an inverted position, and a six degree-of-freedom force-torque sensor (JR3, Woodland, CA) was rigidly secured to the distal tibia (Fig. 1). A series of manual manipulations applying IE and VV torques was performed through the flexion range [3]. Each specimen was then revised to the alternate revision system, and the manual manipulations were repeated. Joint loads were calculated, and tibiofemoral kinematics were described according to the Grood-Suntay definition [4]. VV and IE kinematics were calculated as a function of flexion angle, VV torque, and IE torque as has been described previously [3]. The knees were analysed at ±6 Nm VV and ±4 Nm IE, and the kinematics were normalized to the zero load path. A paired t-test (p < .05) was employed to identify significant differences between the kinematics of the two knee systems at 10º flexion increments.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 120 - 120
1 Feb 2020
Gonzalez FQ Fattori A Lipman J Negro ND Brial C Figgie M Hotchkiss R Pressacco M Wright T
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Introduction. The interaction between the mobile components of total elbow replacements (TER) provides additional constraint to the elbow motion. Semi-constrained TER depend on a mechanical linkage to avoid dislocation and have greater constraint than unconstrained TER that rely primarily in soft tissue for joint stability. Greater constraint increases the load transfer to the implant interfaces and the stresses in the polyethylene components. Both of these phenomena are detrimental to the longevity of TER, as they may result in implant loosening and increased damage to the polyethylene components, respectively[1]. The objective of this work was to compare the constraint profile in varus-valgus and internal-external rotation and the polyethylene stresses under loads from a common daily activity between two semi-constrained TER, Coonrad/Morrey (Zimmer-Biomet) and Discovery® (DJO), and an unconstrained TER, TEMA (LimaCorporate). Methods. We developed finite element (FE) models of the three TER mechanisms. To reduce computational cost, we did not include the humeral and ulnar stems. Materials were linear-elastic for the metallic components (E. Ti6Al4V. =114.3 GPa, E. CoCr. =210 GPa, v=0.33) and linear elastic-plastic for the polyethylene components (E=618 MPa, v=0.46; S. Y. =22 MPa; S. U. =230.6 MPa; ε. U. =1.5 mm/mm). The models were meshed with linear tetrahedral elements of sizes 0.4–0.6 mm. We assumed a friction coefficient of 0.02 between metal and polyethylene. In all simulations, the ulnar component was fixed and the humeral component loaded. We computed the constraint profiles in full extension by simulating each mechanism from 8° varus to 8° valgus and from 8° internal to 8° external rotation. All other degrees-of-freedom except for flexion extension were unconstrained. Then, we identified the instant during feeding that generated the highest moments at the elbow[2], and we applied the joint forces and moments to each TER to evaluate the stresses in the polyethylene. To validate the FE results, we experimentally evaluated the constraint of the design with highest polyethylene stresses in pure internal-external rotation and compared the results against those from a FE model that reproduced the experimental setup (Fig.1-a). Results. For each design, the constraint profiles in varus-valgus (Fig.2-a) were similar to internal-external rotation (Fig.2-b). All designs showed a lax zone in which the mechanisms rotated freely and an engagement zone in which the mobile components contacted, resulting in load transfer. The laxity of the Coonrad/Morrey and the Discovery® was similar and lower than that of the TEMA. After engagement, the stiffness of the TEMA was less than that of the Discovery® and the Coonrad/Morrey. The TEMA showed the lowest polyethylene stresses of all three designs under demanding loads during feeding. Only Discovery® and Coonrad/Morrey had zones reaching permanent deformation (Fig.3). For the Coonrad/Morrey, with the highest polyethylene stresses, the experimental and computational constraint profiles were similar (Fig.1-b). Discussion. The TEMA unconstrained design transferred less moment than semi-constrained designs, reducing the burden on the implant interfaces. Moreover, the TEMA design had lower stresses in the polyethylene components due to the combination of less constraint and a lack of sharp edges on the articular surfaces. For any figures or tables, please contact the authors directly


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 164 - 165
1 Mar 2010
Kim Y Park W Kim K Kim K Lee S
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Even though spinal fusion has been used as one of the common surgical techniques for degenerative lumbar pathologies, high stiffness in the fusion segment could generate clinical complications in the adjacent spinal segment. To avoid these limitations of fusion, the artificial discs have recently used to preserve the motion of the treated segment in lumbar spine surgery. However, there have been lacks of biomechanical information of the artificial discs to explain current clinical controversies such as long-term results of implant wear and excessive facet contact forces. In this study, we investigated the biomechanical performance for three artificial discs in the lumbar spinal segments by finite element analysis. A three-dimensional finite element model of five spinal motion segments, from L1 to S, in intact lumbar spine was reconstructed from CT images. Finite element models of three artificial discs, semi-constrained and metal on polyethylene core type (ProDisc. ®. II, Spine Solutions Inc., USA; Type I), semi-constrained and metal on metal type (MaverickTM, Medtronic Sofamor Danek Inc., USA; Type II), and un-constrained and metal on polyethylene core type (SB ChariteTM III, Dupuy Spine Inc., Switzerland; Type III) were developed. Each artificial disc was inserted at L4–L5 segment, respectively. Upper and lower plates of artificial discs were attached on the L4 and L5 vertebrae. Some parts of ligaments and intervertebral disc in L4–L5 motion segment were removed to insert artificial discs. Nonlinear contact conditions were applied on facet joints in lumbar spine model and artificial discs. Bottom of sacrum was fixed on the ground and 5Nm of flexion and extension moments were applied on the superior plate of L1 with 400N of compressive load along follower load direction. In extension, all three artificial disc models showed higher rotation ratio at the surgical levels, but lower rotations at the adjacent levels than those in the intact model. There was no big difference of the intersegmental rotations among the artificial disc models. For the comparison of the peak von-Mises stresses on the polyethylene core in flexion, 52.3 MPa in type I implant was higher than 20.1 MPa in Type III implant while the peak von-Mises stresses were similar, 25.3 MPa and 26.5 MPa in Type I and III, respectively in extension. The facet contact forces at the surgical level for the artificial disc models showed 140 to 160 N in extension whereas the facet contact force in the intact model was 60 N. From the results of this study, we could investigate the biomechanical characteristics of three different artificial disc models. The relative rotation at the surgical level would be increases at the early outcome after total disk replacement. The semi-constrained type artificial disc could generate higher wear risk of the implant than unconstrained type. Also all types of artificial disc model have higher risk of facet joint arthrosis, and especially in the semi-constrained and metal on metal type. The results of the present study suggested that more careful care must be taken to choose surgical technique of total disc replacement surgery


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_II | Pages 107 - 107
1 Apr 2005
N’Guyen L Odent T Bercovy M Touzet P Prieur A Glorion C Pouliquen J
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Purpose: From 1985 to 2001, 31 total knee arthroplasties were performed for 17 adolescents or young adults with idiopathic juvenile osteoarthritis. The purpose of this work was to evaluate functional and radiological outcome. Material and methods: Overall functional outcome was assessed with the Steinbrocker classification. Knee function was evaluated with the IKS score. Several types of prostheses were implanted: constrained GSB (n=14), cemented semi-constrained tri-CCC tri-compartment with a rotatory platform (n=10), non-cemented semi-constrained ROCC (n=1), LCS (n=2) including non-cemented, and FINN (n=2) (two custom-made rotation hinge prostheses implanted in the same patient). Fourteen prostheses involved bilateral implants, including three dual implantation procedures. Results: Mean age at implantation was 20 years five months (14–29). There were fourteen girls and three boys. Eight had systemic idiopathic juvenile osteoarthritis and nine a polyarticular form. The Steinbrocker staging was: II (n=5,) III (n=6), IV or bedridden (n=4). Ten patients had two hip prostheses before bilateral knee arthroplasty. Mean follow-up was 4.5 years (1–12). Among the 31 operated knees, 16 were pain free, 14 minimally painful, and one painful due to loosening. The joint score was very good (n=18), good (n=4), and poor (n=5). Radiographically, normal alignment was found for 29 knees. Lucent lines were observed for 10 of the 14 GSB constrained prostheses. We did not observe any evidence of lucent lines for the non-cemented tri-compartment prostheses. Complications were: limited skin necrosis (n=1), bilateral supracondylar fracture one year after implantation (n=1). Discussion: Outcome has been encouraging for total knee prostheses in patients with idiopathic juvenile osteoarthritis. These arthroplasties allow spectacular functional improvement. The few series reported have also reported very good results. Cemented tri-compartment semi-constrained implants appear to provide better stability at five years. Biologically sealed tri-compartment prostheses would be a very satisfactory solution due to the preservation of bone stock


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 2 - 2
1 Aug 2020
Matache B King GJ Watts AC Robinson P Mandaleson A
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Total elbow arthroplasty (TEA) usage is increasing owing to expanded surgical indications, better implant designs, and improved long-term survival. Correct humeral implant positioning has been shown to diminish stem loading in vitro, and radiographic loosening in in the long-term. Replication of the native elbow centre of rotation is thought to restore normal muscle moment arms and has been suggested to improve elbow strength and function. While much of the focus has been on humeral component positioning, little is known about the effect of positioning of the ulnar stem on post-operative range of motion and clinical outcomes. The purpose of this study is to determine the effect of the sagittal alignment and positioning of the humeral and ulnar components on the functional outcomes after TEA. Between 2003 and 2016, 173 semi-constrained TEAs (Wright-Tornier Latitude/Latitude EV, Memphis, TN, USA) were performed at our institution, and our preliminary analysis includes 46 elbows in 41 patients (39 female, 7 male). Patients were excluded if they had severe elbow deformity precluding reliable measurement, experienced a major complication related to an ipsilateral upper limb procedure, or underwent revision TEA. For each elbow, saggital alignment was compared pre- and post-operatively. A best fit circle of the trochlea and capitellum was drawn, with its centre representing the rotation axis. Ninety degree tangent lines from the intramedullary axes of the ulna and humerus, and from the olecranon tip to the centre of rotation were drawn and measured relative to the rotation axis, representing the ulna posterior offset, humerus offset, and ulna proximal offset, respectively. In addition, we measured the ulna stem angle (angle subtended by the implant and the intramedullary axis of the ulna), as well as radial neck offset (the length of a 90o tangent line from the intramedullary axis of the radial neck and the centre of rotation) in patients with retained or replaced radial heads. Our primary outcome measure was the quickDASH score recorded at the latest follow-up for each patient. Our secondary outcome measures were postoperative flexion, extension, pronation and supination measured at the same timepoints. Each variable was tested for linear correlation with the primary and secondary outcome measures using the Pearson two-tailed test. At an average follow-up of 6.8 years (range 2–14 years), there was a strong positive correlation between anterior radial neck offset and the quickDASH (r=0.60, p=0.001). There was also a weak negative correlation between the posterior offset of the ulnar component and the qDASH (r=0.39, p=0.031), and a moderate positive correlation between the change in humeral offset and elbow supination (r=0.41, p=0.044). The ulna proximal offset and ulna stem angle were not correlated with either the primary, or secondary outcome measures. When performing primary TEA with radial head retention, or replacement, care should be taken to ensure that the ulnar component is correctly positioned such that intramedullary axis of the radial neck lines up with the centre of elbow rotation, as this strongly correlates with better function and less pain after surgery


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 9 | Pages 1198 - 1204
1 Sep 2008
Peden JP Morrey BF

This study reports our experience with total elbow replacement for fused elbows. Between 1982 and 2004, 13 patients with spontaneously ankylosed elbows were treated with a linked semi-constrained non-custom total elbow implant. The mean age at operation was 54 years (24 to 80). The stiffness was a result of trauma in ten elbows, juvenile rheumatoid arthritis in one, and rheumatoid arthritis in two. The patients were followed for a mean of 12 years (2 to 26) and were evaluated clinically using the Mayo Elbow Performance Score, as well as radiologically. A mean arc from 37° of extension to 118° of flexion was achieved. Outcomes were good or excellent for seven elbows at final review. Ten patients felt better or much better after total elbow replacement. However, there was a high complication rate and re-operation was required in over half of patients. Two developed peri-operative soft-tissue breakdown requiring debridement. A muscle flap with skin grafting was used for soft-tissue cover in one. Revision was undertaken in one elbow following fracture of the ulnar component. Three patients developed a deep infection. Three elbows were manipulated under anaesthesia for post-operative stiffness. Prophylactic measures for heterotopic ossification were unsuccessful. Total elbow replacement for the ankylosed elbow should be performed with caution. However, the outcome can be reliable in the long term and have a markedly positive impact on patient function and satisfaction. The high potential for complications must be considered. We consider total elbow replacement to be an acceptable procedure in selected patients with reasonable expectations


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_8 | Pages 16 - 16
1 May 2019
Flatow E
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Total shoulder arthroplasty has gone through several generations, as instruments and implant designs have given surgeons both more options in the alignment of the components and more guidance in the best choices to make. However, while the measurement of alignment has become more sophisticated, the importance of particular aspects of alignment to actual patient comfort and function has been less completely characterised. Overstuffing of the joint and proud humeral heads have been most associated with clinical failure. The efforts to avoid this can be divided into two camps: 1.) The anatomic school, who believe an experienced surgeon can divine the correct anatomy that existed before the distortions of arthritis began, and that the surgeon should make free-hand cuts and alignments to restore the normal anatomy. 2.) The cutting-guide school, who believe that average versions and positions avoid error and that soft-tissue balancing requires occasional deviations from “normal” anatomy. Reverse total shoulder replacement in contrast is a semi-constrained implant, with built-in “internal impingement” at the extremes of motion, which can cause notching and/or instability (levering out). Initial European experience favored placing the humeral component in 0 degrees, but most surgeons have gravitated toward 15–20 degrees of retroversion to allow easy conversion from/to a hemiarthroplasty as needed. Increased retroversion may block internal rotation, and increased anteversion limits external rotation


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 319 - 319
1 Nov 2002
Pradhan N Borrill J Blan J Porter M
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It is usually assumed that there is a correlation between the number of previous operations and the clinical outcome of revision knee arthroplasty though it has not been studied and published. We reviewed our series of 81 revision knee arthroplasty patients to ascertain if a correlation exists. All patients had a semi-constrained prosthesis implanted. Methods: We analysed the data of 81 revision knee arthroplasty patients performed at Wrightington Hospital with an average follow-up of 31 months (1yr – 6yrs). The number of previous operations on each knee were noted and the clinical outcome was determined using a patient satisfaction questionnaire. Results: Of the 81 patients; 18 were enthusiastic with the clinical outcome; 38 were satisfied; eight were non-committal; 17 were disappointed. Seventy four per cent of patients with one previous operation were enthusiastic or satisfied with the revision surgery outcome in comparison to 55.5% and 0% of patients with two and three previous surgery respectively. Conclusion: The trend from the above figures suggests that as the number of previous operations increases the likelihood of satisfactory clinical outcome decreases, in revision total knee replacement using semi-constrained prosthesis


The Journal of Bone & Joint Surgery British Volume
Vol. 73-B, Issue 1 | Pages 53 - 56
1 Jan 1991
Barrett D Cobb A Bentley G

We measured joint position sense in the knee by a new method which tests the proprioceptive contribution of the joint capsule and ligaments. The leg was supported on a splint, and held in several positions of flexion. The subjects' perception of the position was recorded on a visual analogue model and compared with the actual angle of flexion. Eighty-one normal and 45 osteoarthritic knees were examined, as were 10 knees with semi-constrained and 11 with hinged joint replacements. All were assessed with and without an elastic bandage around the knee. There was a steady decline in joint position sense with age in subjects with normal knees. Those with osteoarthritic knees had impaired joint position sense at all ages (p less than 0.001). Knee replacement improved the joint position sense slightly (p less than 0.02); semi-constrained replacement had a greater effect than hinged replacement. The effect of an elastic bandage in subjects with poor position sense was dramatic, improving accuracy by 40% (p less than 0.001). It is proposed that reduced proprioception in elderly and osteoarthritic subjects may be responsible for initiation or advancement of degeneration of the knee