The clinical outcome of revision knee replacement after unicompartmental knee arthroplasty versus primary total knee arthroplasty: 8–17 years follow-up study of 49 patients

When unicompartmental knee arthroplasty (UKA) failure occurs, a revision procedure to total knee arthroplasty (TKA) is often necessary. We compared the long-term results of this procedure to primary TKA and evaluated whether they are clinically comparable. Twenty-one patients underwent UKA conversion to TKA between 1991 and 2000. The results of these patients were compared to the group of 28 primary TKA patients with the same age, sex and operation time point. The long-term outcomes were evaluated using clinical and radiological analysis. The mean follow-up period of the patients was 10.5 years. The UKA revision patients were more dissatisfied, as measured by the WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) scale (0–100 mm) compared to the primary TKA patients (pain 18.1/7.8; p = 0.014; stiffness 25.7/14.4, p = 0.024; physical function 19.0/14.8, p = 0.62). Two patients were revised twice in the UKA revision group. There was one revision in the primary TKA group (p = 0.39). Improvement in range of motion (ROM) was better in the TKA patients compared to the UKA revision patients (8.2°/–2.6°, p = 0.0001). We suggest that UKA conversion to TKA is associated with poorer clinical outcome as compared to primary TKA.     

A 5 to 8 year follow-up study of the Rotaglide mobile bearing total knee arthroplasty

We report the medium-term outcomes of the Rotaglide mobile bearing total knee arthroplasty (RTK). Between 1994 and 1999, 357 RTK prostheses were implanted at our institution. Of 150 knees attending for follow-up, none had needed revision. Mean American Knee Society Score (AKSS), Oxford knee score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 8 years were 153.6, 23.1 and 16.5, respectively. Radiological analysis revealed no prosthesis with signs of impending failure requiring revision. Survivorship was 100% in those attending. However, we are aware of two failures requiring revision, both of which were due to infection. We have no reported failures requiring revision due to aseptic loosening. This may be a result of the implant design. Limitations of the study include loss to follow-up and radiological analysis. The RTK gives good to excellent medium-term results and we support its continued use.

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Résumé  Nous rapportons les résultats à moyen terme de la prothèse à plateau mobile de type Rotaglide. Entre 1994 et 1999, 357 prothèses ont été implantées dans notre établissement. Sur 150 genoux pris en compte dans le suivi aucun n’a nécessité de révision. Les scores AKSS, Oxford et Womac à 8 ans ont été respectivement de153.6, 23.1 et de 16.5. L’analyse radiologique n’a pas montré de signes de faillite nécessitant une révision. La courbe de survie est de 100% sur cette période. Nous surveillons deux échecs qui ont nécessité une révision dont tous les deux sont secondaires à une infection. Nous n’avons pas non plus rapporté d’échecs nécessitant une révision pour descellement aseptique. Ces bons résultats sont secondaires au design de l’implant. Les limites de cette étude sont les perdus de vue de l’analyse radiologique. Nous pouvons conclure que la prothèse totale du genou de type Rotaglide RTK permet de bons et d’excellents résultats à moyen terme et nous sommes encouragés à poursuivre son utilisation.

     

Isolated acetabular revision after total hip arthroplasty: results at 5–9 years of follow-up

The purpose of the study was to determine whether isolated revision of the acetabular component can be successfully performed without disturbing the femoral stem and to determine the fate of the unrevised femoral stem following revision. Fifty-seven hips in 55 patients underwent isolated acetabular revision without removal of the femoral component. Thirty-three hips with minimal acetabular deficiency required no bone grafting; the remaining 24 hips were treated by morselized or structural allograft in addition to a new acetabular component. Twenty-two of these 24 hips demonstrated incorporation of the bone graft. A mean follow-up of 5.8 (5–9) years, all femoral and acetabular components were judged to be stable and well fixed.

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Résumé Le but de létude est de déterminer si la révision isolé du composant acétabulaire peut être exécutée avec succès sans déranger la tige fémorale et, deuxièmement, de déterminer lavenir de la tige fémorale laissée en place, après cette révision. Cinquante-sept hanches chez cinquante-cinq malades ont subi une révision acétabulaire isolée sans ablation du composant fémoral. Trente-trois hanches avec une déficience acétabulaire minime nont exigé aucune greffe osseuse; les 24 hanches restantes ont été traitées par une allogreffe morcelée ou structurelle associée à un nouveau composant acétabulaire. Vingt-deux de ces 24 hanches ont montré une incorporation de la greffe dos. A un suivi moyen de 5,8 ans (5 à 9 ans) tout les composants fémoraux et acétabulaires ont été jugés stables et bien fixés.

     

Cementless cup fixation in total hip arthroplasty after 5–8 years

A series of 199 total hip arthroplasties was performed using a porous-coated, hemispherical press-fit acetabular cup. At a mean follow-up of 91.5 months 158 cups were available for clinical and radiological review. The mean age of the patients at the time of the index arthroplasty was 62.5 years. The mean Harris Hip score at final follow-up was 87.3. No shells were revised although eccentric polyethylene wear prompted liner replacement in two cases. Osteolysis was noted in six cases but predominantly in relation to the femoral stem. Focal pelvic osteolytic lesions were rare. All the cups were classified as stable on radiography.     

No detrimental effect of ligament balancing on functional outcome after total knee arthroplasty: a prospective cohort study on 129 mechanically aligned knees with 3 years’ follow-up

Background and purpose — In the classical mechanical alignment technique, ligament balancing is considered a prerequisite for good function and endurance in total knee arthroplasty (TKA). However, it has been argued that ligament balancing may have a negative effect on knee function, and some authors advocate anatomic or kinematic alignment in order to reduce the extent of ligament releases. The effect of the trauma induced by ligament balancing on functional outcome is unknown; therefore, the aim of this study was to investigate this effect.

Patients and methods — 129 knees (73 women) were investigated. Mean age was 69 years (42–82), and mean BMI was 29 (20–43). Preoperatively 103 knees had a varus deformity, 21 knees had valgus deformity, and 5 knees were neutral. The primary outcome measure was the Knee injury and Osteoarthritis Outcome Score (KOOS). Secondary outcome measures were the Oxford Knee Score (OKS) and patient satisfaction (VAS). All ligament releases were registered intraoperatively and outcome at 3 years’ follow-up in knees with and without ligament balancing was compared

Results — 86 knees were ligament balanced and 43 knees were not. Ligament-balanced varus knees had more preoperative deformity than varus knees without ligament balancing (p = 0.01). There were no statistically significant differences in outcomes between ligament-balanced and non-ligament-balanced knees at 3 years’ follow-up. No correlation was found between increasing numbers of soft tissue structures released and outcome.

Interpretation — We did not find any negative effect of the trauma induced by ligament balancing on knee function after 3 years.     

Outcome of isolated tibial polyethylene insert exchange after uncemented total knee arthroplasty: 27 patients followed for 8–71 months

Background?The outcome of performing isolated tibial polyethylene insert exchange (ITPIE) after total knee arthroplasty (TKA) is under debate. We evaluated the survival probability of ITPE after uncemented TKA.

Method?27 patients (27 knees) with an ITPIE performed mean 9 (0.9–17) years after the initial TKA were included in the study (22 patients also had the patellar component replaced simultaneously). All patients had their exchange performed at our department between 1997 and 2001 and had their latest follow-up examination mean 40 (8–71) months after the exchange.

Results?During the follow-up, 2 patients had total knee revision because of aseptic loosening and 2 patients had isolated patella component exchange (in 1 of the patients, combined with a new ITPIE). Kaplan-Meier survival analysis gave a survival probability of 80% at 34 months of follow-up.

Interpretation?The short-term survival after an ITPIE was similar to that of a total knee revision with exchange of all components. Since the ITPIE is a much smaller operation with fast rehabilitation, we recommend it in elderly patients with a well-fixed and wellaligned prosthesis without surface damage of the components.     

Patella in total knee arthroplasty: to resurface or not to��a cohort study of staged bilateral total knee arthroplasty

The aim of this study was to assess medium term results of patellar resurfacing in total knee arthroplasty, specifically looking at anterior knee pain, patellofemoral function and need for reoperation. A prospective cohort study was conducted with patients undergoing staged bilateral knee arthroplasty with the patella being resurfaced only on one side. This was due to change in the clinical practice of the senior author. Sixty patients were reviewed clinically and radiologically on a regular basis. The surgery was either performed or supervised by the senior author in all cases. All patients received the cemented press-fit condylar© prosthesis. The Knee Society clinical rating system was used. Scores were recorded pre-operatively and post-operatively at three months, one year, two years and three yearly thereafter. The mean age of patients in the study group was 75 years (range: 62–89 years). There were 42 women and 18 men in the study. The mean duration of follow-up was 4.5 years (range: 2–12 years). There was no significant difference in the pre-operative scores in both groups. There were significantly better scores (p < 0.05) on the resurfaced side as compared to the non-resurfaced side at final follow-up. No revision was carried out for patellofemoral complications on the resurfaced side. Four patients required revision in the form of patellar resurfacing on the non-resurfaced side for persistent anterior knee pain. Patellar resurfacing is recommended in total knee arthroplasty for better functional outcome with regards to anterior knee pain and patellofemoral function.     

Long-term outcomes following total hip and total knee arthroplasty in patients with Paget's disease of bone (PDB) – A national study

BackgroundThe incidence of total hip and total knee arthroplasty (THA/TKA) is 3.1- and 1.7-fold higher in patients with Paget's disease of bone (PDB) compared to age-matched controls. No large studies or joint registry reports exist describing outcomes following THA or TKA in PDB patients.MethodsThe study objectives were to investigate the outcomes following THA or TKA in PDB patients using national registry data. Data were requested from the Scottish Arthroplasty Project for all PDB patients undergoing THA or TKA in Scotland from 1996 to 2013.ResultsBetween 1996 – 2013, 144 patients underwent primary THA and 43 patients underwent primary TKA for PDB in Scotland. Following primary THA, the most common surgical complications within one year were haematoma (1.4%), and surgical-site infection (1.4%). The overall incidence of dislocation was 2.8%. Revision THA was performed in 2.8% of patients. THA implant survival was 96.3% (CI:92.8–99.8) at 10-years, and patient survival was 50.0% (CI:39.6–60.4) at 10-years. Following TKA, only one revision surgery occurred within one year (2.3%). Revision TKA was performed in 4.7% of patients, across the whole study period. TKA implant survival was 94.5% (CI:87.1–100) at 10-years; patient survival was 38.3% (CI:16.7–59.9) at 10-years. Compared with published literature and registry data, implant longevity and patient survival are comparable between PDB patients and the general population.ConclusionThis is the largest reported series of outcomes following primary THA/TKA in PDB patients. PDB patients are not at increased risk of surgical complications following primary THA or TKA compared with the general population.     

Volumetric measurement of periprosthetic bone remodeling: prospective 5 years follow-up after cemented total hip arthroplasty

Introduction Periprosthetic bone remodeling after total hip arthroplasty (THA) is a well recognized phenomenon. Many authors have published osteodensitometric data with DEXA analysis. This study based on computerized tomography (CT). Materials and methods The objective of the current project is to collect prospective volumetric bone density data with a clinical CT study in six patients after cemented THA (titanium alloy stem). The follow-up time is 5 years. A data set of about 100,000 bone voxels for each femur was collected. Bone density was observed by dint of an osteodensitometric computer program. The median results were shown in seven regions of interest (ROI) around the prosthesis stem, according to Gruen. Results The statistical analysis of the six cases after 60 months with respect to the postoperative control demonstrated a significantly lower density in ROI 2 (−125.5HU, P = 0.014), ROI 3 (−116.7HU, P = 0.023), ROI 4 (−54.5HU, P = 0.023), ROI 5 (−90.9HU, P = 0.014) and ROI 6 (−104.9HU, P = 0.014). Maximum density decrease was observed in ROI 2 and 3. The statistical analysis of the six cases after 60 months with respect to the 24 months control demonstrated a significantly lower density in ROI 2 (−62.6HU, P = 0.014), ROI 5 (−62.9HU, P = 0.023). There was a density decrease in ROI 3, 4, 6, 7 which was not significant and a slight increase in ROI 1. Conclusion To our knowledge, this is the first collection of fully prospective 5 years 3D periprosthetic density data. The CT method used in the study presented here measures three-dimensionally, while the frequently used DEXA (dual X-ray absorptiometry) method measures two-dimensionally. The data are also unique as they are suitable for direct patient-specific 3D finite element meshing and biomechanical calculation. They can be graphically post-processed in order to obtain cross-sectional or 3D displays of density patterns.     

Causes of a painful total knee arthroplasty. Are patients still receiving total knee arthroplasty for extrinsic pathologies?

Purpose

Whilst patients undergoing total knee replacements generally have good relief of their symptoms, up to 20% complain of persisting pain. Revision rates have therefore been rising, particularly so for unexplained pain. We reviewed the causes of painful total knee replacements including extrinsic causes.

Methods

Forty-five consecutive patients referred to our department with painful total knee replacement were reviewed with our standard protocol, including history and examination, inflammatory markers and radiological studies including radiographs of the hip and knee and computed tomography scan of the knee joint.

Results

Of the 45 patients, 15 patients had degenerative hip and lumbar spine disease which resolved after injections of the relevant joints. Nine patients had unexplained pain.

Conclusions

Patients may still be undergoing knee arthroplasty for degenerative lumbar spine and hip osteoarthritis. We suggest heightened awareness at pre- and post-operative assessment and thorough history and examination with the use of diagnostic injections to identify the cause of pain if there is doubt.     

Cementless total hip arthroplasty for osteonecrosis of the femoral head in systemic lupus erythematosus: a study with 10–16 years of follow-up

Objectives

The purpose of the present study was to describe the long-term results of total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH) in patients with systemic lupus erythematosus (SLE).

Methods

From 1994 to 2001, 18 cementless THAs (14 SLE patients) were included in the present study. Four hips (three patients) were lost to follow-up. The remaining 14 hips (11 patients) were available for evaluation. The mean follow-up period was 13.1 (range, 10.0–16.4) years. The follow-up rate was 77.8 %. The mean age at the time of surgery was 35.2 (range, 27.4–51.0) years.

Results

Mean preoperative Harris Hip Score was 37.4 (range, 17.1–63.1) points, which improved to 94.5 (range, 73.9–100) points at final follow-up. Two hips had dislocation and were treated successfully with closed reduction. No patient in this study group had deep venous thrombosis or pulmonary embolism. One hip had peroneal nerve palsy. No superficial or deep wound infection was observed. Two hips of two patients required reoperation due to dislodgement of a polyethylene insert. With revision of the acetabular component for any reason considered to be a failure, the 10-year survival rate was 93 % (95 % CI, 0.79–1).

Conclusion

We have reported the long-term results of THA for ONFH with SLE. Although several reports have noted that the results of THA for ONFH are less favorable than those for osteoarthritis, the long-term results of THA for ONFH with SLE were acceptable. THA is an acceptable option for patients with advanced-stage or an extended region of ONFH.     

Relationship between patients in hospital affects recovery from total knee arthroplasty (TKA)–A prospective study

Background

The interaction between patients is rather important source of information about surgery and recovery. Patients always prefer particularly to compare themselves with others of relatively similar ability, opinion and situation. Exploration of patients' dyads, however, is rare and needs further elaboration as to the significance of fellow patients. This study was designed to determine in whether and how preoperative assignment affects TKA's results.

Long-term results of Charnley arthroplasty: A 12–16-year follow-up study

A retrospective, long-term study was initiated to analyze clinical function, failures, and radiographic status in 95 Charnley low-friction arthroplasties performed during 1973–1977. Only patients with primary osteoarthrosis were included, and no patients were lost during the follow-up period. At the follow-up evaluation, 39 patients (41 hips) were deceased. Ten hips were revised (including 3 of the deceased patients), leaving 47 hips available for follow-up evaluation. Four patients (5 hips) were interviewed by telephone, and the remaining 42 hips were examined by the authors. With a mean follow-up period of 14 years, many of the patients had excellent pain relief with a mean Harris hip score for pain of 42 points (maximum, 44 points). Ninety-four percent of the patients were satisfied with their results. The survivorship for all 95 hips was 92% at 10 years and 83% at 16 years. Follow-up radiographs revealed that three (7%) of the femoral components were definitively loose, but only two (5%) of the acetabular components were probably loose. Forty-three percent of the hips had signs of polyethylene wear of the cup. The clinical and radiographic outcome is, in spite of an early cementing technique, very good in this long-term follow-up study.     

Does anticoagulation do more harm than good?: A comparison of patients treated without prophylaxis and patients treated with low-dose warfarin after total knee arthroplasty

A cohort of 785 patients treated without any form of thromboprophylaxis was compared with an identical group of 957 patients treated with 6 weeks of low-dose warfarin. All complications seen within 90 days of surgery were recorded. The control group had a total complication rate of 2.2%, with a death rate from thromboembolic disease of 0.0% and a total death rate of 0.2%. The warfarin group had a total complication rate of 4.7%, with a death rate from thromboembolic disease of 0.0% and a total death rate of 0.1%. Both deaths in the control group were from cardiac disease, while the death in the warfarin group was due to a massive gastrointestinal bleeding. The warfarin group had twice the infection rate of the control group.