Patellar resurfacing as a second stage procedure for persistent anterior knee pain after primary total knee arthroplasty

Purpose

Knee pain after total knee arthroplasty may be caused by an unresurfaced patella. Secondary isolated resurfacing of the previously unresurfaced patella in total knee arthroplasty remains controversial. The aim of this retrospective study was to evaluate the outcome after patellar resurfacing as a second stage procedure.

Methods

The study included 22 patients (13 female/nine male) who underwent resurfacing of the patella with a mean follow-up of 61.8 ± 39.2 months. The mean age of the patients was 60 ± 9.7 years at the time of operation. The average period between total knee arthroplasty and patellar resurfacing was 26.3 ± 15.2 months. The patient’s subjective satisfaction was assessed by a custom-made questionnaire.

Results

The mean Knee Society Score improved significantly from 60.1 ± 8.3 to 77.0 ± 6.3 (p = 0.0063). The mean functional score also improved significantly from 42.7 ± 2.3 to 60.2 ± 3.9 (p = 0.001). Three patients (13.6%) needed further operative revision.

Conclusions

Although clinical scores showed significant improvement some patients continued to have pain and remained dissatisfied without detecting a specific reason. Further studies are needed to better elucidate the benefit of patellar resurfacing as second stage procedure.     

Patellar resurfacing versus nonresurfacing in total knee arthroplasty: A meta-analysis of randomised controlled trials

Purpose

Patella resurfacing or nonresurfacing in total knee arthroplasty remains controversial. The aim of this study was to evaluate the efficacy of patellar resurfacing through an evaluation of the current literature.

Methods

We carried out a meta-analysis of randomised controlled trials comparing total knee arthroplasties performed with and without patellar resurfacing. Outcomes of reoperation, anterior knee pain and knee scores were analysed.

Results

Fourteen trials assessing 1,725 knees were eligible. The absolute risk of reoperation was reduced by 4 % (95 % confidence interval, 2–6 %) in the patellar resurfacing arm (between-study heterogeneity, P = 0.05, I² = 42 %), implying that one would have to resurface 25 patellae (95 % confidence interval, 17–50 patellae) in order to prevent one reoperation. There was no difference between the two groups in terms of anterior knee pain, knee pain score, Knee Society score and knee function score. But in the studies followed up for a mean time of not less than five years, a difference was found between the two arms in Knee Society scores (RR = 2.14, 95 % confidence interval, 0.76–3.52; P = 0.002).

Conclusions

The available evidence indicates that patellar resurfacing reduces the risk of reoperation after total knee arthroplasty. Patellar resurfacing patients may make a difference in long-term follow-up (five or more 5 years) of Knee Society scores. In other aspects, the benefit of patellar resurfacing is limited. Additionally, more carefully and scientifically designed randomised controlled trials are required to further prove the claim.     

The influence of patella height on soft tissue balance in cruciate-retaining and posterior-stabilised total knee arthroplasty

Purpose

Although the patella reduced or everted position has recently been recognised as an important factor influencing soft tissue balance during assessment in total knee arthroplasty (TKA), the influence of patella height on soft tissue balance has not been well addressed. Therefore, the relationship between soft tissue balance and patella height was investigated and differences between cruciate-retaining (CR) and posterior-stabilised (PS) TKA were compared.

Methods

Forty consecutive patients blinded to the type of implant received, were randomised prospectively. Using lateral radiographs, pre-operative patella height was measured. Using an offset-type tensor designed to measure the soft tissue balance with a reduced patellofemoral (PF) joint and femoral component in place, soft tissue balance was intra-operatively assessed in CR TKA (n = 20) and PS TKA (n = 20) in osteoarthritic patients. The joint component gap and varus ligament balance at zero, ten, 45, 90 and 135° of knee flexion with the patella reduced were measured.

Results

In PS TKA, the joint component gap positively correlated with patella height at 90 and 135° of knee flexion. However, there was no correlation between joint component gap and patella height at other flexion angles in PS TKA and any flexion angle in CR TKA. Varus ligament balance showed no significant correlation with patella height in either CR or PS TKA.

Conclusion

Analysis of soft tissue balance and patella height only showed a positive correlation in joint component gap at a high flexion angle (90 and 135°) in PS TKA but not in other parameters examined. Pre-operative measurement of patella height may be an important factor for predicting an intra-operative flexion gap in PS TKA.     

Evaluation of patellofemoral joint in ADVANCE® Medial-pivot total knee arthroplasty

Purpose

ADVANCE® Medial Pivot (MP) (Wright Medical) total knee arthroplasty (TKA) was established to replicate normal tibio-femoral knee joint kinematics, however, its influence on the patello-femoral (PF) joint is unclear. The purpose in this study was to assess the PF joint conditions in Advance MP TKA, via radiography and three-dimensional image-matching software.

Methods

Ten subjects with osteoarthritis were treated with the ADVANCE MP TKA. Pre-operatively and one month after surgery, skyline views at 30, 60, and 90° of flexion were taken, and patella shift and tilt were measured. With 2D–3D registration techniques using software, implant orientations were matched with the pre-operative CT and changes in the anterior part of the femoral prosthesis, condylar twist angle (CTA) for femoral rotation, and tibial rotation were evaluated. The relationships between morphological and rotational changes were evaluated.

Results

There were significant differences in patella tilt at 60° and patella shift at all angles between pre- and post-operation (p < 0.05). No correlation was found between morphological changes in the anterior femur with patella tilt and shift. A positive correlation between postoperative CTA and patella shift at 90° was found (p < 0.05); however, no correlation was found between rotational alignment of the tibial component and patella tilt and shift.

Conclusions

ADVANCE MP TKA changed patello-femoral joint kinematics, compared to that found before surgery. The kinematic features were mainly due to the design concepts for tibio-femoral joint motion, indicating the difficulty to reproduce normal patello-femoral joint kinematics after TKA.     

Medial patellofemoral ligament anatomy: is it a predisposing factor for lateral patellar dislocation?

Purpose

Because the medial patellofemoral ligament (MPFL) is the primary restraint to lateral dislocation of the patella, we aimed, in this controlled study, to verify whether the MPFL with different measurements could be considered another predisposing factor for patellar dislocation.

Methods

A group of 100 consecutive individuals without the criteria for patellar dislocation (trochlear dysplasia, patella alta and lateral patellar tilt) was recruited as a control group and underwent magnetic resonance imaging (MRI) study and another group of 50 patients with patellar instability. Femoral condyles, interepicondylar distance, length and thickness of the MPFL were measured.

Results

In the control group, the MPFL was 38–60 mm long. Individuals with patellar instability who had no episode of patellar dislocation had a 4.11-mm longer ligament than controls (p = 0.032), while patients with instability with a previous history of dislocation had a 13.54-mm longer MPFL than controls (p < 0.001). Thickness of the MPFL at the patellar insertion was lower in individuals with patellar instability with a history of dislocation (p < 0.001). An instability coefficient (IC) less than 1.3 indicates that the MPFL is insufficient.

Conclusions

Individuals with patellar instability and previous patellar dislocation present with longer MPFL when compared to controls, and an associated IC less than 1.3 can be considered a predisposing factor for patellar dislocation. Treatment of patellar instability is a challenge, and it is difficult to identify what is the predisposing factor. This study has verified the measurements of the MPFL for the first time and presents values of thickness and length that can be considered as indications for surgical reconstruction.Level of evidence: III.     

The incidence of trochlear dysplasia in anterior cruciate ligament tears

Purpose

The purpose of the present epidemiologic study is to record the radiographic presence of trochlear dysplasia and patella alta in patients who undergo anterior cruciate ligament (ACL) reconstruction as a potential underlying factor for post-operative anterior knee pain (AKP).

Methods

All consecutive cases of skeletally-mature ACL-deficient knees that would undergo ACL reconstruction in three different hospitals were prospectively included during a six-month period. Inclusion criteria were acute and sub-acute ACL injury with no previous ipsilateral knee operation. Patients with chronic ACL tears, prior-to-ACL-injury history of patellar instability or other PF disorders were excluded from the study.

Results

A total of 299 knees were included (mean age 32 ± ten years). Forty-four (14.7 %) knees had a positive ‘crossing sign’ in the lateral X-rays and 255 (85.3 %) had no sign of trochlear dysplasia (p < 0.01). Among the cases with trochlear dysplasia, 41 (93 %) had type A trochlear dysplasia with the presence only of the ‘crossing sign’ and three (7 %) had type C trochlear dysplasia. Patellar height results included a mean Caton-Deschamps index of 1.0 ± 0.14 (0.5–1.4). Twenty (6.6 %) knees had an index of less than 0.8, and two (0.6 %) knees had an index less than 0.6. In contrast, 15 (5.0 %) knees had an abnormal value of more than 1.2, indicating patella alta.

Conclusions

The most important finding of the study is the increased prevalence of trochlear dysplasia and patella alta in patients with ACL injury, when compared to the incidence of trochlear dysplasia and patella alta in the general population in the literature. This finding could sound as an alert of a possible additional risk factor for post-operative anterior knee pain after ACL reconstruction.     

How often is functional range of motion obtained by manipulation for stiff total knee arthroplasty?

Purpose

To evaluate how often manipulation under anesthesia (MUA) can achieve functional flexion ≥ 90 degrees and identify predictor for successful outcome of MUA for stiff total knee arthroplasty (TKA).

Methods

Demographic data, range of motion, and surgical and anesthetic information of 143 MUAs were retrospectively analyzed from 2000 to 2011.

Results

One-hundred thirty-six out of 143 patients (95 %) improved mean range of motion (ROM) from pre-MUA 62 ± 17° to final ROM 101 ± 21° (p < 0.001). Flexion ≥ 90 degrees was achieved in 74% (106/143) of patients. Regional anesthesia was identified as predictor of successful MUA outcome (p = 0.007, OR: 8.5, 95 % CI: 1.2-66.7).

Conclusions

Although the proportion of patients regaining flexion ≥ 90 degrees following MUA was less than those patients with simple overall ROM increase, the functional flexion ≥ 90 degrees was achieved in the vast majority of patients with stiff TKA following MUA.     

Total knee arthroplasty in elderly patients with severe Kashin-Beck disease of the knee

Purpose

The treatment of elderly KBD knee remains a significant clinical challenge, and clinical data are lacking. This study aimed to prospectively determine the functional outcomes of total knee arthroplasty (TKA) in adult patients with severe Kashin-Beck disease (KBD) of the knee.

Method

Fifteen cases that included 18 occurrences of KBD of the knee were treated by primary knee arthroplasty and followed up for at least two years. Clinical assessments for each patient were performed at time zero (pre-operatively), one, three, six and 12 months and yearly thereafter. The efficacy measures included the visual analogue scale (VAS) pain score, Hospital for Special Surgery (HSS) score, and Functional Score for Adult Tibetans with Kashin-Beck Disease (FSAT-KBD) as well as radiographic findings.

Results

All patients were followed for a mean length of 32.47±10.05 months. All force lines in the lower limbs had been improved significantly. No radiographic evidence of loosening or changes in component positioning was observed at the last follow up. The VAS decreased significantly during the first six months after surgery and was maintained until the last follow up (p < 0.01). Similar trends were found in both HSS and FSAT-KBD, which increased significantly post-operatively (p < 0.01).

Conclusion

Knee arthroplasty can reduce pain and improve function in patients with severe KBD of the knee. Additional studies will be necessary to confirm our findings.     

The natural history of a newly developed flexion contracture following primary total knee arthroplasty

Purpose

We investigated the incidence, natural history, and functional consequences of a newly developed flexion contracture after total knee arthroplasty (TKA).

Methods

Forty patients with full knee extension preoperatively who developed a postoperative flexion contracture were match-paired 1:2 with 80 patients who had full extension. The incidence of a newly developed flexion contracture, ROM, and Knee Society scores (KSS) at six weeks, four months, and one year were analysed.

Results

The incidence of a new flexion contracture at six weeks was 14 %, but diminished to 5 % and 0.3 % at four months and one year, respectively. One year after surgery, there was no difference in the KSS (p = 0.5).

Conclusions

This study showed that the majority of patients who developed a new flexion contracture after TKA have full knee extension one year postoperatively. Moreover, knee extension and KSS at one year are equivalent to those patients who did not developed a flexion contracture.     

One-stage total knee arthroplasty for patients with osteoarthritis of the knee and extra-articular deformity

Purpose

The purpose of this paper is to review our experience and study the feasibility and clinical results of one-stage total knee arthroplasty (TKA) for patients with osteoarthritis of the knee with extra-articular deformity.

Methods

Nine patients with osteoarthritis of the knee associated with extra-articular deformity underwent one-stage TKA from June 2006 to April 2010. There were two men and seven women, with an average age of 51 years (range 34–69 years); four of them had tibial deformities and five had femoral deformities. Eight of the cases resulted from malunion after fracture healing and one from femoral recurvatum. Six of the cases had uniplanar and three had biplanar deformities. The average angles of the femoral deformities were 13.3° in the coronal plane (8–22) and 11.3° in the sagittal plane (6–15); one femur had 10° external rotational deformity. Tibial deformity of 16° in the coronal plane (11–22) was noted, and one had sagittal plane deformity of 21°.

Results

All patients were followed for an average of 29 months. The average Hospital for Special Surgery (HSS) knee score improved from 18.7 points pre-operatively to 89.8 points at the time of last follow-up; the range of knee motion improved from 46.7° preoperatively to 100.6° postoperatively. The average angle of mechanical axis deviation was restored from 11.8° preoperatively to 1° postoperatively. One of the patients had unsatisfactory clinical results due to delayed union at the osteotomy site. No complications such as infection, deep vein thrombosis, ligament instability, low level or subluxed/dislocated patella or component loosening were observed. One-stage TKA with intra-articular correction of the extra-articular deformity was performed in seven patients, included proper planning, appropriate bone cuts to restore alignment and the necessary soft tissue releases to balance the knee in flexion and extension. Two patients underwent simultaneous extra-articular correctional osteotomy and TKA because the deformity was so large. Five knees that had good collateral ligamentous stability and balance received a posterior stabilised prosthesis; four knees that had ligamentous instability received a constrained condylar knee (CCK) prosthesis.

Conclusions

One-stage TKA is a technically difficult but effective treatment for patients with osteoarthritis of the knee and extra-articular deformity. If feasible we recommend TKA with intra-articular bone resection and soft tissue balancing.     

Platelet-rich plasma for the treatment of patellar tendinopathy: clinical and imaging findings at medium-term follow-up

Purpose

The purpose of this study was to evaluate the efficacy of multiple platelet-rich plasma (PRP) injections on the healing of chronic refractory patellar tendinopathy, and report the quality and duration of the clinical improvement up to a medium-term follow-up.

Methods

Forty-three patients (mean age, 30.6 years; mean BMI, 24.7; 42 men, one woman) affected by chronic patellar proximal tendinopathy were enrolled in this trial. Eleven patients were affected by bilateral tendinopathy. They underwent three ultrasound guided intra-tendinous injections of five millilitres PRP, two weeks apart from each other. Patients were prospectively evaluated initially, then after two, six, and up to mean 48.6 ± 8.1 months of follow-up (minimum evaluation at 36 months). The following evaluation tools were used: Blanzina, VISA-P, EQ-VAS for general health, and Tegner scores. Patients’ overall satisfaction and time to return to sport were also reported.

Results

Good and stable results were documented over time, with the VISA-P score increasing from 44.1 ± 15.6 at baseline to 61.4 ± 22.2 at two months, 76.6 ± 25.4 at six months, and 84.3 ± 21.6 at four years’ follow-up. The same trend was confirmed by the other scores used, and 80 % of the patients were satisfied and returned to previous sports activities. Significantly poorer results were obtained in patients with a longer history of symptoms, and poor results were also observed in bilateral lesions. No correlation between ultrasonographic and clinical findings could be found.

Conclusions

Multiple injections of PRP provided a good clinical outcome for the treatment of chronic recalcitrant patellar tendinopathy with stable results up to medium-term follow-up. Patients affected by bilateral pathology and presenting a long history of pain obtained significantly poorer results.     

Prevalence of osteoarthritis and clinical results after the Elmslie-Trillat procedure: a retrospective long-term follow-up

Purpose

Tibial tuberosity medialisation may be followed by osteoarthritis in the long term due to increased patellofemoral contact pressure and altered knee joint kinematics. We aimed to (1) systematically assess the grades of tibiofemoral and patellofemoral osteoarthritis ten to 30 years after the Elmslie-Trillat procedure and (2) to evaluate long-term knee function and activities of daily living.

Methods

A total of 26 patients (30 knees) were re-evaluated at a minimum follow-up of 12.3 years (mean 20.9 ± 4.1 years). Osteoarthritis was graded according to Kellgren and Lawrence (K/L) and Sperner. All patients were clinically evaluated using the Knee Society Score (KSS) and Knee injury and Osteoarthritis Outcome Score (KOOS). Radiographic data were compared to an age-, sex- and body mass index-matched control group of healthy patients.

Results

Radiographic evaluation revealed seven cases (23.3 %) with advanced osteoarthritis (K/L and Sperner grades 3 and 4). However, the observed differences from the matched cohort were not statistically significant (P = 0.189). A positive correlation was found between the age at index procedure and tibiofemoral osteoarthritis at follow-up (P = 0.013). Patient satisfaction was relatively high, showing a mean KSS of 89.9 (knee score) and 94.8 (function score), and a mean KOOS of 78.7. However, we noted four cases of frequent patellar re-dislocations and three total knee arthroplasties.

Conclusions

The Elmslie-Trillat procedure was associated with several cases of advanced tibiofemoral and patellofemoral osteoarthritis in the long term, especially if the procedure was performed late. Clinical results were still good to excellent in the majority of patients despite some observed cases of re-dislocations and decreased ability to perform sports.     

Pre-operative arthritis severity as a predictor for total knee arthroplasty patients’ satisfaction

Purpose

Studies have shown that up to 25 % of TKA patients are dissatisfied with the implanted knee, even if registry data shows ten-year revision rates below 5 %. It has been the question of our study, if it would be possible to identify those patients at risk for dissatisfaction pre-operatively.

Methods

The data of 1,121 consecutive TKA patients with a follow-up between one and six years have been analysed retrospectively. Demographic, radiologic and perioperative variables have been recorded and all patients were asked by questionnaire for satisfaction with the implanted knee. Logistic regression models have been used to identify significant risk factors.

Results

The data of 996 patients (89 %) were complete, 849 (85.2 %) reported satisfaction and 147 (14.8 %) dissatisfaction. Patients’ satisfaction was independent of the time after operation (p = 0.285). The only factor which influenced patients’ satisfaction was the osteoarthritic severity. In comparison to severe arthritis Kellgren Lawrence IV°, the risk for dissatisfaction was 2.556-fold elevated for arthritis grade III° (p < 0.001) and 2.956-fold higher for grade II° (p = 0.001).

Conclusions

Patients suffering from mild or moderate osteoarthritis are at risk for dissatisfaction after TKA. The TKA indication in those patients should therefore be critically proven. Furthermore, to adjust patients’ expectations, the elevated dissatisfaction risk in case of mild or moderate osteoarthritis should be included into patients’ pre-operative information.     

The Use of Biologic DMARDS Identifies Rheumatoid Arthritis Patients with More Optimistic Expectations of Total Knee Arthroplasty

Background

Preoperative expectations of total knee arthroplasty (TKA) correlate with postsurgical satisfaction, and are linked to outcomes. Rheumatoid arthritis (RA), and other chronic diseases, may lower expectations, although new biologic medications have greatly enhanced patients’ quality of life.

Questions/Purposes

The purpose of this study is to compare preoperative expectations of RA to those of matched osteoarthritis (OA) patients undergoing TKA, and examine the subset of RA on biologic DMARD therapy.

Methods

For a cross-sectional study, RA and OA identified from an institutional TKA registry were matched on age, sex, prior TKA, and preoperative function. Expectations were measured using the Hospital for Special Surgery (HSS) Knee Expectations Survey. Expectations and quality of life measures were assessed preoperatively and scores were compared between RA and OA.

Results

One hundred fourteen RA cases, 46.5% on biologics, were matched to 228 OA cases. The average expectations score was not significantly lower for RA compared to OA (72.9 ± 20.7 vs. 77.2 ± 18.3, p = 0.040. RA on biologics had expectations similar to OA (total expectation score 76.3 ± 18.1 vs. 77.4 ± 17.4, p = 0.71), while RA not on biologics had expectations that were significantly lower (69.9 ± 22.4 vs. 77.1 ± 19.0, p = 0.03).

Conclusion

Use of biologics in RA patients was associated with higher expectations, similar to those of OA patients, but the effect on outcomes is not known. Further studies should assess the effect of higher expectations in RA patients on outcomes.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9380-1) contains supplementary material, which is available to authorized users.     

A comparison of conventional and patient-specific instruments in total knee arthroplasty

Purpose

Several authors have observed that standard instrumentation (SI) may be insufficient for addressing component malalignment. Patient-matched cutting blocks (PMCB) technology was introduced to improve surgeons’ ability to achieve a neutral postoperative mechanical axis following total knee arthroplasty (TKA). The current retrospective study was designed to compare the ability of SI and PMCB to achieve a hip-knee-ankle angle (HKA) within ±3° of the ideal alignment of 180°.

Methods

Between October 2009 and December 2012, 170 TKAs in 166 patients (four bilateral) using VISIONAIRE (Smith & Nephew) PMCB technology were performed. Additionally, 160 TKAs in 160 consecutive patients that had received a total knee arthroplasty using SI during the same time period were used as a control group, All surgeries were performed by the same surgeon. Standardized pre- and postoperative long-leg standing x-rays were retrospectively evaluated to compare the two patient cohorts.

Results

X-rays were available for analysis for 156 knees in the SI group and 150 in the PMCB group. The average post-surgical HKA was 178.7 ± 2.5 in the SI group and 178.4 ± 1.5 in the PMCB group. However, the rate of ± 3° outliers was 21.2 % in the SI group and 9.3 % in the PMCB group. There were no intraoperative complications with the use of PMCB technology or SI.

Conclusions

PMCB technology proved superior to conventional instrumentation in achieving a neutral mechanical axis following TKA. Further follow-up will be needed to ascertain the long-term impact of these findings.     

Scorpio single radius total knee arthroplasty. A minimal five-year follow-up multicentric study

Purpose

Our goal was to evaluate the five-year follow-up results of the Scorpio single radius total knee arthroplasty.

Method

We performed a retrospective study based upon a multicentre database to evaluate the minimum five-year follow-up clinical and radiological results of 747 patients (831 knees) who underwent primary Scorpio single radius total knee arthroplasty.

Results

The mean age of the patients was 71.9 years. At a minimal five-year follow-up, 141 patients were lost to follow-up, 83 patients had died, eight patients had undergone revision of a component, and the remaining 589 patients (602 knees) had a complete clinical and radiological evaluation after a median of six years (range, 5–8). The mean clinical component of the knee score was 92.2 points, and the mean functional component of the knee score was 76.9 points. At last follow-up, 530 of the 602 knees were rated as excellent or good. Only four knees developed patellar complications requiring revision. The survival rate at six years was 95.2% ± 1.9% and 98.3% ± 0.6 with revision for any reason and revision for mechanical failure as the end point, respectively.

Conclusion

This medium-term study indicates favourable clinical and radiological results for this single flexion-extension radius design arthroplasty, with a low complication rate on the patellar side.     

Double-bundle anatomical versus single-bundle isometric medial patellofemoral ligament reconstruction for patellar dislocation

Purpose

The purpose of this study was to evaluate reconstruction of the medial patellofemoral ligament (MPFL) using the double-bundle anatomical or single-bundle isometric procedure with respect to the patients’ clinical outcomes.

Methods

In this retrospective study, we evaluated the clinical outcome of double-bundle anatomical versus single-bundle isometric reconstruction of the MPFL for patellar dislocation patients. Sixty-three patients were included in this study from August 2004 to January 2008. From August 2004 to September 2006, MPFL reconstruction using a single-bundle isometric technique was performed in 21 patients (26 knees). Since October 2006, the double-bundle anatomical reconstruction of the MPFL has been used as the routine surgical procedure. It was performed in 37 patients (44 knees). Fifty-eight patients (70 knees) could be followed up. According to the different techniques, we divided the patients into two groups: group D with double-bundle anatomical reconstruction (37 patients) and group S with single-bundle isometric reconstruction (21 patients). Clinical evaluation consisted of the number with a patellar re-dislocation, patellar apprehension sign, Kujala score, subjective questionnaire score, the patella lateral shift rate and patellar tilt angle measured by cross-sectional CT scan.

Results

According to the Kujala score and the subjective questionnaire score, the outcome of the double-bundle group was better than the outcome of the single-bundle group especially in the long-term. Patellar re-dislocation occurred in three patients in the group S, while no re-dislocation occurred in the group D. In total, 26.9 % of group S was considered to have patellar instability, compared to 4.54 % of the group D. After operation, the patellar tilt angle (PTA) and the patella lateral shift rate (PLSR) were restored to the normal range, with statistical significance (P < 0.05) compared to the preoperative state.

Conclusion

Single- and double-bundle reconstruction of the MPFL can both effectively restore patella stability and improve knee function. However, outcomes in the follow-up period showed that the double-bundle surgery procedure was much better than in single-bundle surgery.     

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.