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.     

全膝关节置换术中髌骨置换与否对膝前痛发生的影响

[目的]回顾性分析、比较全膝关节置换术中髌骨置换与否对膝前痛发生的影响,为临床治疗提供参考。[方法]对1994年10月~2004年10月行人工全膝关节置换术病人125例(148膝)按髌骨置换(84膝)和未置换(64膝)分为2组,并对其随访资料进行分析,膝关节评分采用HSS评分系统,髌骨评分采用Feller评分标准。结果使用SPSS统计软件进行统计学分析。[结果]置换组HSS评分由术前的(39.6±39.8)分进步为末次随访时的(90.9±8.2)分,髌骨评分由(14.4±6.4)分进步到(25.2±4.8)分,膝前痛分数也由(4.6±3.9)分进步为(10.6±4.1)分;未置换组HSS评分由术前的(38.8±9.8)分进步为(90.2±8.9)分,髌骨评分由(14.2±6.2)分进步到(25.1±4.8)分,膝前痛分数也由(4.8±3.8)分进步为(10.3±4.1)分。2组患者末次随访时膝前痛均较术前明显减轻,差异有显著性意义;置换组与未置换组比较,膝前痛减轻的差别无显著性意义。[结论]无论髌骨置换与否,患者的合理选择和正确的手术操作是避免术后膝前痛的关键所在。     

Secondary resurfacing of the patella in mobile-bearing total knee arthroplasty

OBJECTIVE: We aim to evaluate the impact of secondary patellar resurfacing in patients with patellar-related anterior knee pain who have undergone a mobile-bearing primary knee arthroplasty without resurfacing. MATERIALS: A total of 2950 primary Low Contact Stress (DePuy, Warsaw, Ind) mobile-bearing knee arthroplasties without patellar resurfacing were carried out between March 1992 and March 2003. Thirteen patients (0.4%) underwent secondary patellar resurfacing for patellar-related anterior knee pain. The mean age of the patients was 67.8 years. There was a mean time of 28 months to the secondary resurfacing procedure. RESULTS: Only 4 patients had an unequivocal improvement in their symptoms at a mean follow-up of 45 months (range, 3-92 months). No morbidity was noted from the procedure. CONCLUSION: The success rate of secondary patellar resurfacing is poor and patients should be counseled carefully.     

Functional improvement after knee arthroplasty without resurfacing of patella

There has been no universal agreement so far regarding the necessity of patellar resurfacing in total knee arthroplasty. As resurfacing has been reported to be associated with high incidence of complications, this practice has been avoided in our Department. A report is given on the analysis of the functional outcome of 60 knee arthroplasties without patellar resurfacing in 53 patients (7 bilateral) followed up for twelve to thirty months, with special regard to the functions closely related to patelloformal articulation. The underlying diagnosis was osteoarthritis in 78.3%, rheumatoid arthritis in 13.3%, and posttraumatic arthritis in 8.3% of the patients. Graded according to the modified knee-rating system of the Hospital for Special Surgery, excellent or good results were obtained in the case of 55 knees (91.6%) and the mean score improved from 53.6 points preoperatively to 82.6 points following arthroplasty. Subjective and objective functional assessment of stair climbing and transfer activities have shown no functional deficit attributed to the patellofemoral joint of the replaced knee.     

初次全膝关节置换术后膝前痛预防的研究进展

全膝关节置换术（total knee arthroplasty,TKA）是治疗终极膝关节病变的有效方法,能有效缓解疼痛,纠正畸形,改善功能,进而提高患者的生活质量.目前,患者的满意程度越来越被认为是评价TKA的一个重要因素.而膝前痛作为初次TKA后的常见并发症,是指发生于膝前或者髌骨周围的疼痛,这严重影响了患者膝关节功能的改善和其对手术的满意程度.因此,膝前痛的减轻成为TKA的重要目标.目前,认为膝前痛的主要机制是髌股关节的高接触应力造成的软骨下骨内压升高和并发于髌骨运行轨迹异常导致的髌骨周围软组织病变.近年来针对如何预防全膝关节置换术后膝前痛的发生进行了大量研究,但是由于各种各样的原因,至今为止不管是髌骨置换,保留髌骨行髌骨周围去神经化,还是活动平台体都不能取得确切而良好的效果.由此可见,初次TKA后膝前痛的防治仍然是一个棘手的问题.此问题的解决,需要对膝前痛发生原因、膝关节假体及髌股关节生物力学特性做进一步研究,并经过大规模的随机对照试验的论证.     

Asymmetric patella resurfacing in total knee arthroplasty

Three hundred consecutive primary, cemented, condylar total knee arthroplasties (TKAs) were reviewed for the presence of asymmetric patella resurfacing using a postoperative Merchant or sunrise patellar radiograph. Twenty-one knees in 14 patients were found to have the patella asymmetrically resurfaced. Asymmetric resurfacing typically involved the inadvertent preferential resurfacing of the lateral facet with underresection of bone from the medial patellar facet. All patients underwent follow-up for a minimum of 5 years, with a mean follow-up of 7.5 years. Of the 21 knees, 3 revisions were required for patellar complications. One patellar component was loose on radiographs and there was marked patellofemoral pain in 6 knees. Overall, 11 of 21 knees (52%) underwent revision or were recommended for revision for patellar complications or had anterior knee pain that limited activities. Inadvertent asymmetric patella resurfacing using the kinematic condylar implant adversely affects the outcome after TKA.     

股骨假体设计对保留髌骨全膝关节置换术后膝前痛的影响

目的探讨不同股骨假体设计对保留髌骨全膝关节置换术(totalkneearthroplasty,TKA)后膝前痛发生率及疼痛程度的影响。方法2002年1月15日～2月15日间,门诊共随访保留髌骨TKA后患者44例59膝,所有手术均于1998年10月～2001年10月间施行,术前诊断均为骨关节炎,术后随访3～40个月,平均19.1个月。依据目前较普遍认同的标准:股骨假体髌骨滑槽的深度、宽度、是否对称,髌骨滑槽的延伸范围,股骨假体前方向远端移行是否平滑等将股骨假体分为“髌骨友好”与“髌骨不友好”两组。病例排除的标准:(1)膝关节屈曲小于80°者;(2)X线影像提示存在股骨假体屈曲大于3°、股骨前方皮质切迹(notching)、髌骨高位或低位等外科操作失误者。按美国膝关节学会评分方法及患者自我感觉对疼痛发生率及疼痛程度进行量化分析。结果入选的40例51膝分属上述两组,“髌骨友好”组21膝,术后膝前痛评分平均为1.58(0～8)分;“髌骨不友好”组30膝,术后膝前痛评分平均为3.32(0～6)分,两组之间差异有非常显著性意义(t=4.642,P<0.01)。“髌骨友好”与“髌骨不友好”两组无膝前痛患者构成比分别为64%与9%,两组之间差异有非常显著性意义(χ2=15.457,P<0.01)。结论股骨假体设计的不同会直接影响保留髌骨TKA术后膝前痛的发生率及疼痛程度,行保留髌骨TKA     

全膝关节置换术后疼痛的争议与探索

<正>全膝关节置换术是膝关节终末期病变非常有效的治疗方法,但手术后的疼痛是至今尚未根本解决的主要并发症之一。本期4篇论文围绕这一问题,进行了深入研究[1-4]。其中1篇是关于围手术急性疼痛的多模式镇痛中引入经皮神经电刺激辅助镇痛的研究[1]。当前围手术期的镇痛采用的多模式方法主要以药物镇     

Secondary patella resurfacing in painful non-resurfaced total knee arthroplasties

Purpose

In Norway, 19 % of revisions of non-resurfaced total knee arthroplasties done for knee pain between 1994 and 2011 were Secondary Patella Resurfacing (SPR). It is, however, unclear whether SPR actually resolves the pain. The aim was to investigate prostheses survival and clinical outcomes following SPR.

Method

A total of 308 knees (301 patients) with SPR were used to assess implant survival, and a sub-cohort (n?=?114 out of 301 patients) with Patient Reported Outcome Measures (PROMs) data were used to assess the clinical outcomes. The EuroQol (EQ-5D), the Knee Injury and Osteoarthritis Outcome Score, and Visual Analogue Scales on satisfaction and pain were used to collect PROM data. Outcomes were analysed by Kaplan-Meier, Cox regression, and multiple linear regression.

Results

The five- and ten-year Kaplan-Meier survival percentages were 91 % and 87 %, respectively. Overall, 35 knees were re-revised at a median follow-up of eight years and pain alone (10 knees) was the main cause of re-revision. Younger patients (<60 years) had nearly nine times higher risk of re-revision compared to older patients (>70 years) (RR?=?8.6; p?<?0.001). Mean EQ-5D index score had improved from 0.41 (SD 0.21) preoperative to 0.56 (SD 0.25) postoperative following SPR. A total of 63 % of patients with PROM data were satisfied with the outcomes of SPR.

Conclusion

The long-term prostheses survival following SPR was satisfactory, although not as good as for primary knee replacement. Patients’ health related quality of life improved significantly following SPR. Still, more than a third of patients with PROMs data were dissatisfied with the outcomes of the SPR procedure.

     

Failure of total knee arthroplasty with or without patella resurfacing

Background and purpose

Patella resurfacing during primary total knee arthroplasty (TKA) is disputed and new prosthesis designs have been introduced without documentation of their survival. We assessed the impact on prosthesis survival of patella resurfacing and of prosthesis brand, based on data from the Norwegian Arthroplasty Register.

Patients and methods

5 prosthesis brands in common use with and without patella resurfacing from 1994 through 2009 were included n = 11,887. The median follow-up times were 9 years for patella-resurfaced implants and 7 years for implants without patella resurfacing. For comparison of prosthesis brands, also brands in common use with only one of the two treatment options were included in the study population (n = 25,590). Cox regression analyses were performed with different reasons for revision as endpoints with adjustment for potential confounders.

Results

We observed a reduced overall risk of revision for patella resurfaced (PR) TKAs, but the statistical significance was borderline (RR = 0.84, p = 0.05). At 15 years, 92% of PR and 91% of patella non resurfaced (NR) prostheses were still unrevised. However, PR implants had a lower risk of revision due to pain alone (RR = 0.1, p < 0.001), but a higher risk of revision due to loosening of the tibial component (RR = 1.4, p = 0.03) and due to a defective polyethylene insert (RR = 3.2, p < 0.001).At 10 years, the survival for the reference NR brand AGC Universal was 93%. The NR brands Genesis I, Duracon, and Tricon (RR = 1.4–1.7) performed statistically significantly worse than NR AGC Universal, while the NR prostheses e.motion, Profix, and AGC Anatomic (RR = 0.1–0.7), and the PR prostheses NexGen and AGC Universal (RR = 0.4–0.5) performed statistically significantly better. LCS, NexGen, LCS Complete (all NR), and Tricon, Genesis I, LCS, and Kinemax (all PR) showed no differences in this respect from the reference brand. A lower risk of revision (crude) was found for TKAs performed after 2000 as compared to those performed earlier (RR = 0.8, p = 0.001).

Interpretation

Although revision risk was similar for PR and NR TKAs, we found important differences in reasons for revision. Our results also indicate that survivorship of TKAs has improved.Use of a patellar component (patella resurfacing) during primary total knee arthroplasty (TKA) is still disputed. The search for improvements has resulted in the introduction of several new designs that are widely used nowadays, although there is no documentation about their survival.The question of whether or not primary patella resurfacing should be recommended has led to several observational studies, randomized clinical trials (RCT), and meta-analyses (Forster 2004, Parvizi et al. 2005, Nizard et al. 2005, Pakos et al. 2005) and review articles (Meneghini 2008). In a critical appraisal of the available evidence, Calvisi et al. (2009) were not able to find any clear superiority between either of the two treatments due to methodological limitations in the published studies. Studies based on data from arthroplasty registers have found a higher risk of revision when the patella was left untreated (Furnes et al. 2002, the Swedish Knee Arthroplasty Register Annual Report 2009, Clements et al. 2010). Furnes et al. 2002) found that the increased revision risk was mainly related to revisions due to pain. Some recent studies have, however, indicated that there is no difference in patients'' perception of postoperative pain in the two groups of treatment (Johnston et al. 2009, Lygre et al. 2010) and that the observed differences in risk of revision due to pain may be caused by the exclusive option of a secondary patella resurfacing of the originally patella unresurfaced knee. This is supported by a recent study from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) that suggested that surgeons may be more inclined to revise a patella non resurfaced implant knee with a secondary patella resurfacing if the patient presents later with knee pain, given that the option is still available (Clements et al. 2010)Few studies have compared survival of different prosthesis brands and implant designs, but a previous study (Furnes et al. 2002) from the Norwegian Arthroplasty Register (NAR) did not find any statistically significant short-term differences in revision rates between the most commonly used brands in Norway. Other national arthroplasty registers with longer follow-up have reported statistically significant differences between some commonly used brands in their annual reports (Australian Orthopaedic Association National Joint Replacement Registry Annual Report 2009, The Swedish Knee Arthroplasty Register Annual Report 2009).Based on data in the NAR, we compared overall survival of cemented knee prostheses with and without resurfacing of the patella, and assessed the survival of some widely used TKA brands.     

The efficacy of patellar decompression for improving anterior knee pain following total knee arthroplasty without patellar resurfacing

Background

Anterior knee pain remains common following total knee arthroplasty (TKA). In this study, we evaluated the efficacy of patellar decompression via drilling for the treatment of anterior knee pain following TKA without patellar resurfacing.

Methods

A prospective cohort study was performed in 271 consecutive patients who underwent primary total knee replacement with patellar decompression (study group, n = 131) or without decompression (control group, n = 140). The patients were assessed according to the Knee Society rating, clinical anterior knee pain score, and British Orthopaedic Association patient-satisfaction score in each group. Each assessment was performed without the examiner knowing whether the patella had been decompressed. Radiographic evaluations were also performed according to the Knee Society scoring system for functional activity and our own severity grade system for patellofemoral articular change.

Results

There were no adverse events following patellar decompression. The overall prevalence of anterior knee pain was not significantly different between groups (p = 0.71). However, patients presenting pain over grade II after the operation in the study group were statistically low (p = 0.01). The overall postoperative knee scores were higher in the study group, but there were no significant differences between groups (p = 0.0731). Analyses of the radiographs revealed similar postoperative outcomes in both groups of knees.

Conclusions

As we observed significantly lower rates of anterior knee pain and no patellar complications following patellar decompression via drilling in TKA without patellar resurfacing, we recommend performing patellar decompression in cases of total knee replacement without patellar resurfacing.     

膝关节置换术中髌骨置换与非髌骨置换比较的Meta分析

[目的]系统评价全膝关节置换术中髌骨置换与否对术后疗效的影响,为临床治疗提供参考。[方法]全面搜索国内外关于膝关节置换术中髌骨置换和非髌骨置换的随机对照研究资料,按照既定的纳入、排除标准,核定检出符合评价标准的文献,提取所需研究数据,采用RevMan 4.2软件进行Meta分析。[结果]纳入随机对照研究16篇,共计1 922例膝关节置换术。Meta分析结果显示,髌骨置换组术后5年内发生膝前痛的风险降低,加权后RR=0.53,95%CI(0.30,0.94),但5年后二者无明显统计学差异。髌骨置换组术后5年以上发生再手术的风险低,加权后RR=0.35,95%CI(0.18,0.66),但5年内二者无明显统计学差异。膝关节KSS评分不论是亚组分析还是总体分析,均无统计学差异。总体分析结果,KSS评分加权均数差值为0.44,95%CI(-1.22,2.09)。[结论]全膝关节置换术中髌骨置换与非髌骨置换相比,术后5年内膝前痛发生率低,术后5年以上再手术的风险低,关节评分无明显差别。髌骨置换与非髌骨置换的优劣仍需大规模多中心的RCT来进一步研究。     

Radiolucent zone of the patella following total knee arthroplasty without patellar resurfacing

Background

The radiolucent zones in the patella are sometimes observed in patients who have undergone total knee arthroplasty (TKA) without patellar resurfacing. On the basis of radiological findings from our clinical experience, we hypothesize that the pathogenesis of this lesion may be similar to that of the lesions of spontaneous osteonecrosis, and this lesion may be due to both osteoporosis and stress concentration. The present study aimed to determine the incidence of the radiolucent zone after TKA without patellar resurfacing. Moreover, the roles of osteoporosis and patellar morphology, which are related to the stress distribution in the patella, were also investigated.

Methods

We studied 48 knees of 38 patients who underwent primary TKA using the Genesis II prosthesis. Axial radiographs taken 1 year postoperatively were used to assess the incidence of the radiolucent zone. The World Health Organization fracture risk assessment tool (FRAX) score and the preoperative patellar facet angle were compared between patients with and without the radiolucent zones.

Results

Five patellae (10.4 %) showed the radiolucent zones postoperatively (the radiolucent group), whereas no such lesions were found in the remaining 43 patellae (the normal group). The major osteoporotic fracture risk of the radiolucent group calculated using the FRAX was 24.8 % and significantly higher than that in the normal group (14.7 %; p = 0.01). The average patellar facet angle in the radiolucent group was 123.6°, which was significantly smaller than that in the normal group (133.6°; p = 0.003).

Discussion and conclusions

The results of the present study suggest that both underlying osteoporosis and a steep patellar facet angle may play an important role in the pathogenesis of the radiolucent zones in patellae after TKA without patellar resurfacing. Patellar resurfacing may be considered, particularly in osteoporotic patients who have a steep patellar facet angle, to avoid the appearance of the postoperative radiolucent zone in the patella.     

Component rotation and anterior knee pain after total knee arthroplasty.

All patients undergoing cruciate-retaining primary total knee arthroplasty for degenerative osteoarthritis at one center were studied prospectively. Clinical and radiographic followup was obtained at a minimum 5 years in 102 knees in 73 patients. Patients were asked specifically about the presence of the pain in the anterior aspect of the knee in the vicinity of the patella and rated the severity of the pain on a visual analog scale. Significant anterior knee pain rating at least 3 of 10 on the visual analog scale was present in 16 knees (13 patients). Eleven patients with 14 symptomatic knees agreed to undergo computed tomography scanning to accurately determine the rotation of the tibial and femoral components. The epicondylar axis and tibial tubercle were used as references using a previously validated technique. A control group of 11 asymptomatic patients (14 knees), matched for age, gender, and length of followup also underwent computed tomography scanning. All patients in both groups had normal axial alignment. There was a highly significant difference in tibial component rotation between the two groups with the patients with anterior knee pain averaging 6.2 degrees internal rotation compared with 0.4 degrees external rotation in the control group. There also was a significant difference in combined component rotation with the patients with anterior knee pain averaging 4.7 degrees internal rotation compared with 2.6 degrees external rotation in the control group. There was no significant difference in the degree of radiographic patellar tilt or patellar subluxation between the two groups. Patients with combined component internal rotation were more than five times as likely to experience anterior knee pain after total knee arthroplasty compared with those with combined component external rotation. Component malrotation is a significant factor in the development of anterior knee pain after total knee arthroplasty.     

Fracture of the patella after total knee arthroplasty

Patellar fracture after knee arthroplasty was found in 11 patients (12 knees) during a 15-year period. Causes of this fracture include trauma, technical factors, and biophysical factors. The incidence of this infrequent complication was significantly increased after patella resurfacing and revision arthroplasty. Minimally displaced, non-comminuted fractures were immobilized, whereas displaced, comminuted fractures with loose patellar prostheses were treated operatively. At a mean follow-up period of 28 months, the average knee score was 75 points. The average arc of motion was 87 degrees, and six of the 11 patients have returned to their prefracture functional level. Treatment should be individualized on the basis of fracture displacement, comminution, and button fixation.     

全膝关节置换术后膝前痛的原因分析及对策

膝前痛是全膝关节置换术后常见的并发症之一,无论是否进行髌骨置换,都不可避免。膝前痛的持续存在,往往预示着手术的失败。全膝关节置换术后发生膝前痛的原因众多,必须做到积极的预防和合理的治疗。对于疼痛或功能不严重的患者,可以考虑先进行保守治疗;一旦需要进行手术时,必须严格掌握适应证。本文就全膝关节置换术后膝前痛发生的原因及治疗对策作一综述。     

Kinematic changes after bicondylar resurfacing knee arthroplasty

AIM: Knee joint motion appears as a hinge movement around the flexion - extension axis. But corresponding to the rolling-sliding-mechanism and alternative models of knee joint kinematics an instant center pathway must be expected. Objective of the study was the comparison of this pathway when assessed in the sagittal plane in patients with preoperative varus or valgus deformity. METHOD: A total of 40 patients either with varus or valgus deformity (20 in each group) were examined before and 6 months after implantation of PFC(R)-SIGMA prostheses. Apart from the influence of knee joint deformity (35 degrees varus to 24 degrees valgus), a so called soft tissue ratio was investigated. Therefore the relation of thigh and femur as well as lower limb and tibia diameters was calculated and combined in one value. The examination by means of photogrammetry consisted of a standardized chair with passive knee joint movement (90 degrees to 0 degrees flexion) supported by an electric motor. The position of defined skin markers was assessed by digital camara with online transmission to PC. The instant center pathway was then evaluated applying the Reuleaux-technique based on the changes of skin marker positions. RESULTS: Results showed a dependence of the course and dimension of the instant center pathway on the extent of soft tissue ratio as well as knee joint deformity. Small values of the ratio (W = 2.9) were represented by round or oval courses of the pathway whereas increasing ratios (W = 4.0) led to triangular and slightly increased dimensions of the courses. Varus deformitywas primarily combined with an increase of the pathways dimension and in contrast, valgus deformity showed decreased pathways. In each case, dimension normalized after prostheses implantation. CONCLUSION: The instant center pathway of knee joint motion showed for both patient groups characteristic phenomen. They were clearly combined with constitutional and clinical features of each patient.     

Should the patella be resurfaced in total knee arthroplasty? Efficacy of patellar resurfacing

To assess the long-term efficacy of patellar resurfacing, 100 knees were evaluated in 84 patients. The operations were performed between 1978 and 1982. The follow-up period ranged from 60 to 103 months. The diagnosis was degenerative joint disease (DJD) in 83%, rheumatoid arthritis in 12%, and miscellaneous in 5% of the knees. The implant (47 knees) and nonimplant (53 knees) groups were comparable with respect to age, body size, and length of follow-up period. The analysis revealed equivocal results. Considering all diagnostic categories combined, rest pain was marginally better in the resurfaced group (p = 0.04), but this difference resulted from an unequal distribution of subjects between mild and zero pain categories. Pain with walking, maximum walking distance, ability to climb stairs and rise from a chair, active arc of motion, extensor lag, and quadriceps strength were similar in the two groups. When the DJD group was considered separately, no significant difference emerged. There was little evidence to support a recommendation for routine patellar resurfacing in total knee arthroplasty.