Total knee arthroplasty at 15–17 years: Does implant design affect outcome?

Purpose

A study was conducted to compare minimum 15-year survivorship and outcome of the Genesis I and II implants for total knee arthroplasty (TKA).

Methods

We retrospectively reviewed 245 consecutive TKA implanted between January 1995 and October 1997. Genesis I was implanted in 156 knees and Genesis II in 89 knees.

Results

At 15–17 years, 75 patients (31 %) had died, 28 patients (11 %) were lost to follow-up and 11 TKA were revised (4.6 %), including ten Genesis I (6.4 %) and one Genesis II (1.1 %); 131 TKA (53 %) were available for follow-up. Cumulative survivorship was 92.4 % at 15.7 years. Survival in patients <69 years at surgery was lower (88.0 %) compared with patients ≥69 years (98.5 %; p = 0.023). In patients <69 years, Genesis I survival (84.3 %) was worse compared with Genesis II (97.1 %) (p = 0.018). Polyethylene (PE) Insert thickness ≤11 mm had significantly better survivorship (97.1 %) compared with PE >11 mm (56.7 %) (p < 0.0001)

Conclusions

At a minimum of 15 years, the overall (92.4 %) survivorship of Genesis TKA was good, with excellent (98.1 %) survivorship of the Genesis II design. Revision rates were higher with Genesis I in the younger age group and with insert thickness >11 mm, possibly due to longer shelf life of less frequently used sizes.     

Does a high-flexion design affect early outcome of medial unicondylar knee arthroplasty? Clinical comparison at 2 years

Recently, implant companies have sought to target a more active segment of the population with high-flex implants. Our aim was to compare a successful medial UKA implant with its newer high-flex version. Sixty-one patients (nonflex, 33; high-flex [HF], 28) were prospectively followed after medial UKA with a minimum of 2-year follow-up. Patients were evaluated using Short Form 12, Western Ontario and McMaster Osteoarthritis (WOMAC), Knee Society Scores, and range of motion (ROM). The HF group exhibited significantly higher WOMAC Physical Function scores at 3-month follow-up and higher WOMAC Pain and SF-12 Mental Component scores at 2-year follow-up; all other comparisons were not statistically different, including ROM. The HF cohort had significantly higher improvements in Knee Society Function and Knee score at 1- and 2-year follow-up, respectively; all other comparisons yielded no significant differences in mean improvement from baseline, including ROM or survivorship.     

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.     

Does body weight influence outcome after total knee arthroplasty? A 1-year analysis

Obesity has been considered an adverse influence on the outcome of total knee arthroplasty (TKA), and overweight patients often are advised against having a TKA. The role of body weight has not been shown conclusively using objective outcome measures. A group of 180 patients undergoing primary TKA performed by a single surgeon for osteoarthritis was studied prospectively. Their baseline health status and knee scores were recorded, and changes in these measures were studied at 3 and 12 months after surgery. The Nottingham Health Profile was used to assess health status, and the Knee Society score was used to assess clinical outcome. Body mass index was used as a measure of obesity. We found that body weight did not influence adversely the outcome of TKA in the short-term.     

Reverse shoulder arthroplasty in revision of failed shoulder arthroplasty—outcome and follow-up

Purpose

The number of shoulder arthroplasties has increased over the last decade, which can partly be explained by the increasing use of the reverse total shoulder arthroplasty technique. However, the options for revision surgery after primary arthroplasty are limited in cases of irreparable rotator cuff deficiency, and tuberosity malunion, nonunion, or resorption. Often, conversion to a reverse design is the only suitable solution. We analysed the functional outcome, complication rate and patient satisfaction after the revision of primary shoulder arthroplasty using an inverse design.

Methods

Over a ten-year period 57 patients underwent revision surgery for failed primary shoulder arthroplasty using a reverse design. Of the 57 patients, 50 (mean age, 64.2 years) were available after an average follow-up of 51 months. Clinical evaluation included the Constant Murley Score, the UCLA score, and the Simple Shoulder Test, whereas radiological evaluation included plain radiographs in standard projections. Patients were also requested to rate their subjective satisfaction of the final outcome as excellent, good, satisfied or dissatisfied.

Results

Compared to the preoperative status, the overall functional outcome measurements based on standardised outcome shoulder scores improved significantly at follow-up. The overall mean Constant Murley score improved from 18.5 to 49.3 points, the mean UCLA score improved from 7.1 to 21.6 points, and the mean simple shoulder test improved from 1.2 to 5.6 points. The average degree of abduction improved from 40 to 93° (p < 0.0001), and the average degree of anterior flexion improved from 47 to 98° (p < 0.0001). The median VAS pain score decreased from 7 to 1. Complications occurred in 12 cases (24 %).A total of 32 (64 %) patients rated their result as good or excellent, six (12 %) as satisfactory and 12 (24 %) as dissatisfied.

Conclusion

In revision shoulder arthroplasty after failed primary shoulder arthroplasty an inverse design can improve the functional outcome, and patient satisfaction is usually high. However, the complication rate of this procedure is also high, and patient selection and other treatment options should be carefully considered.     

Does repeat tibial tubercle osteotomy or intramedullary extension affect the union rate in revision total knee arthroplasty?: A retrospective study of 74 patients

Background and purpose Tibial tubercle osteotomy (TTO) is an established surgical technique for exposing the stiff knee in revision total knee arthroplasty (RTKA). The osteotomy is usually performed through the anterior metaphyseal cancellous bone of the tibia but it can be extended into the intramedullary canal if tibial stem and cement removal are necessary. Furthermore, repeat osteotomy may be required in another RTKA. We assessed whether intramedullary extension of TTO or repeat osteotomy affected the healing rate in RTKA.Methods We retrospectively evaluated 74 consecutive patients (39 women) with an average age of 60 (29–89) years who underwent 87 TTOs during RTKA. 1 patient had bilateral TTO. 10 patients had repeat TTO and 1 patient received 3 TTOs in the same knee. The osteotomy was extramedullary in 57 knees and intramedullary in 30 knees. Osteotomy repair was performed with bicortical screws and/or wires.Results Bone healing occurred in all the cases. The median time to union was 15 (6–47) weeks. The median healing time for the extramedullary osteotomy group was 12 weeks and for the intramedullary osteotomy group it was 21 weeks (p = 0.002). Repeat osteotomy was not associated with delayed union. Neither intramedullary nor repeat osteotomy was found to increase the complication rate of the procedure.Interpretation Reliable bone healing can be expected with intramedullary extension or repeat TTO in RTKA. However, intramedullary extension of the osteotomy prolongs the union time of the tibial tubercle.     

Treatment of infected total knee arthroplasty. When does implant salvage make sense?

Infection of a total knee arthroplasty can be classified as acute, chronic and haematogenic with and without implant loosening. A differentiated treatment concept for all types of infection is necessary. Furthermore, specific treatment has to be initiated early, as any delay is associated with a worsening of the prognosis. Treatment of infection with implant salvage may be one therapeutic option if the implant is not loose. According to the current literature, therapy with retention of the prosthesis may be promising: (1) in the case of early infection (<3 weeks of ongoing symptoms), (2) with unconstrained implants, (3) in the case of infection with a single organism that is susceptible to antibiotic therapy, (4) if soft tissue coverage is not affected, and (5) if the immune system is not compromised. Chronic infections, (semi-)constrained implants and soft tissue defects have to be considered as contraindications and implants should be removed. Early and consequent therapy with operative débridement and specific long-term antibiotic therapy are necessary to achieve implant salvage. The additional application of antibiotics addressing bacterial biofilms have helped to improve the prognosis. Due to the fact that revision arthroplasty is often associated with limited function after infection of the total knee joint, retention of the implant has to be considered a therapeutic alternative in early infection.     

Does the type of biological valve affect patient outcome?

Patient background mortality and excess mortality related to aortic valve disease may play a greater role than implanted valve type in explaining the observed survival differences after aortic valve replacement. This study attempts to identify the differences between the performance of selected biological valves, given similar patient characteristics and excess mortality. Four biological valve types, the Carpentier-Edwards pericardial and supra-annular valve, Medtronic Freestyle valve and allografts were used for this analysis. Primary data calculated observed patient-survival and median time to structural valvular deterioration. We then used a microsimulation model to calculate age-specific patient survival and reoperation- and event-free life expectancies. The model incorporated the US population mortality and a uniform excess mortality, while the hazards of valve-related events after implantation of the four valve types were estimated from corresponding meta-analysis and primary data. Observed 10-year survival (60-69)-year age group survival and median time to SVD for the different valve types did not differ. Microsimulation calculated, for a 65-year-old male for example, a 10-year survival of 51%, 51%, 53% and 56% for Carpentier-Edwards pericardial and Supra-annular valve, Freestyle and allografts, respectively. Patient life expectancy was 10.8, 10.8, 11.0 and 11.4 years, respectively. Assuming uniform patient characteristics and excess mortality, the observed difference in performance between the four biological valve types is less marked. Patient selection and the timing of operation may explain most of the observed differences in prognosis after aortic valve replacement with biological prostheses.     

Why are total knee replacements revised?: analysis of early revision in a community knee implant registry

Since 1991, 5760 knee arthroplasty procedures done by 53 surgeons have been registered in a community joint implant registry and were reviewed regarding initial revision done within the healthcare system. The 168 revisions done represented 2.9% of the knee arthroplasties between September 1991 and December 2002. Survival was defined as the absence of revision surgery. Death was considered a censored event. Cumulative survival rates for the different total knee arthroplasty configurations were: cemented total knee arthroplasty with all-polyethylene tibia, 99.2%; cemented total knee arthroplasty with metal-backed tibia, 96.3%; hybrid total knee arthroplasty, 89.3%; and unicondylar knee arthroplasty, 87.2%. Cemented total knee arthroplasty with metal-backed tibia had better survival than hybrid total knee arthroplasty, ingrowth total knee arthroplasty, and unicondylar knee arthroplasty. Cemented total knee arthroplasty with a metal-backed tibia did not have better survival than cemented total knee arthroplasty with an all-polyethylene tibia. Gender was not related to survival. Age was related to survival, with older patients' knees surviving longer. Aseptic loosening or wear was the cause of revision in 40.8% of patients having total knee arthroplasty and 46.6% of patients having unicondylar knee arthroplasty, whereas progression of arthritis necessitated unicondylar knee revision in 51.2% of patients having that procedure. This study presents further evidence of the value of and ongoing need for total joint registries. Cemented total knee arthroplasty with all-polyethylene tibia and with metal-backed tibia showed more than 95% 10-year cumulative survival. Hybrid total knee arthroplasty, ingrowth total knee arthroplasty, and unicondylar knee arthroplasties did not show such good results.     

Does knee position at the time of tourniquet inflation affect knee range of motion?

Pneumatic tourniquets about the thigh are commonly employed in lower extremity orthopaedic surgery to maintain a bloodless operative field. The purpose of this study was to determine whether the position of the knee at the time of tourniquet inflation has an impact on knee range of motion (ROM). Passive ROM of the knees of 30 patients was measured with the tourniquet deflated, with the tourniquet inflated while the knees were in extension, and with the tourniquet inflated while the knees were in flexion. The average knee ROM with a deflated tourniquet was 143.0 degrees with a standard deviation of 8.1 degrees (range, 125 degrees -160 degrees ). When the tourniquet was inflated with the knees in extension, the average knee ROM was 143.0 degrees with a standard deviation of 7.8 degrees (range, 125 degrees -159 degrees ). When the tourniquet was inflated with the knees in flexion, the average knee ROM was 143.7 degrees with a standard deviation of 7.8 degrees (range, 124 degrees -160 degrees ). There was a statistically significant difference between the ROM of knees with tourniquet inflation in flexion versus extension (p = .0011.) Although there was a statistical difference, it was concluded that a difference of approximately 1 degrees in knee ROM is not clinically relevant.     

Does pneumatic dilatation affect the outcome of laparoscopic cardiomyotomy?

BACKGROUND: Controversy surrounds the choice of laparoscopic cardiomyotomy as the primary treatment for achalasia or a second-line treatment following the failure of nonsurgical treatment. Laparoscopic cardiomyotomy can be more difficult technically following pneumatic dilatations. The aim of this study was to compare the outcome obtained with primary laparoscopic cardiomyotomy to that achieved when the procedure is performed following failed pneumatic dilatation. METHODS: Laparoscopic cardiomyotomy was performed in seven patients following a median of four pneumatic dilatations (group A) and in five patients as their primary treatment (group B). Outcome was measured using manometry, a modified DeMeester symptom scoring system, and a quality-of-life questionnaire. RESULTS: There were no significant differences between groups A and B in sex, age, preoperative modified DeMeester score, or mean barrier pressure. Six of seven group A patients had evidence of periesophageal and submucosal fibrosis at surgery, but this condition was not seen in group B patients. The operative time was slightly longer in group A patients. There was no difference in complication rates (one primary hemorrhage in group A and one esophageal perforation in group B), and both groups had a significantly improved modified DeMeester score at 6 weeks and at long-term follow-up (median, 26 months). Eleven of 12 patients said that they would choose laparoscopic cardiomyotomy as their primary treatment if newly diagnosed with achalasia. CONCLUSIONS: Laparoscopic cardiomyotomy is safe and effective as a primary or second-line treatment following pneumatic dilatations in patients with achalasia.