Does the grading of chondromalacia patellae influence anterior knee pain following total knee arthroplasty without patellar resurfacing?

OBJECTIVES: The influence of chondromalacia patellae (CMP) on post-operative anterior knee pain (AKP) following total knee arthroplasty (TKA) remains controversial, and few studies have focused on the relationship between them. The purpose of this study was to determine whether different CMP grades affect the incidence of AKP after TKA without patellar resurfacing. METHODS: We performed a retrospective analysis of prospectively collected data on 290 TKAs with the use of the low contact stress mobile-bearing prosthesis, without patellar resurfacing in 290 patients from February 2009 to January 2013. Patients were assessed by the Outerbridge classification for CMP, visual analog scale for AKP, the Knee Society clinical scoring system of knee score (KS), function score (FS), the patellar score (PS) for clinical function, and patients' satisfaction. RESULTS: The intra-operative grading of CMP: grade I in 30 patients, grade II in 68 patients, grade III in 97 patients, and grade IV in 95 patients. The incidence of AKP at 36-month follow-up was 10.3% (30/290). No statistical difference was detected among the different CMP grades in terms of the incidence of AKP (p = 0.995), patients' satisfaction (p = 0.832), KS (p = 0.228), FS (p = 0.713), and PS (p = 0.119) at 36-month follow-up. CONCLUSIONS: The findings may suggest no relevant influence of CMP grading on the incidence of AKP after TKA without patellar resurfacing.

T2 mapping in patellar chondromalacia.

OBJECTIVE: To study the correlation between the T2 relaxation times of the patellar cartilage and morphological MRI findings of chondromalacia. METHODS: This prospective study comprises 50 patients, 27 men and 23 women suffering of anterior knee pain (mean age: 29.7, SD 8.3 years; range: 16-45 years). MRI of 97 knees were performed in these patients at 1.5T magnet including sagittal T1, coronal intermediate, axial intermediate fat sat and T2 mapping. Chondromalacia was assessed using a modified version of Noyes classification. The relaxation time, T2, was studied segmenting the full thickness of the patellar cartilage in 12 areas: 4 proximal (external facet-proximal-lateral (EPL), external facet-proximal-central (EPC), internal facet-proximal-central (IPC), internal facet-proximal-medial (IPM), 4 in the middle section (external facet-middle-lateral (EML), external facet-middle-central (EMC), internal facet-middle-central (IMC), internal facet-middle-medial (IMM) and 4 distal (external facet-distal-lateral (EDL), external facet-distal-central (EDC), internal facet-distal-central (IDC), internal facet-distal-medial (IDM). RESULTS: T2 values showed a significant increase in mild chondromalacia regarding normal cartilage in most of the cartilage areas (p<0.05), except in the internal distal facet (IDC and IDM), EPC, EDL, and IMM. Severe chondromalacia was characterized by a fall of T2 relaxation times with loss of statistical significant differences in comparison with normal cartilage, except in EMC and IMC, where similar values as mild chondromalacia were maintained (p<0.05). CONCLUSIONS: Steepest increase in T2 values of patellar cartilage occurs in early stages of patellar cartilage degeneration. Progression of morphologic changes of chondromalacia to more severe degrees is associated to a new drop of T2 relaxation times approaching basal values in most of the areas of the patellar cartilage, except in the central area of the middle section, where T2 values remain increased.

Utilidad de la resonancia magnética en la evaluación del mal alineamiento patelar / Usefulness of magnetic resonance imaging in the evaluation of patellar malalignment

Objetivos. Evaluar la utilidad de la resonancia magnética (RM) tomada en 20° de flexión de rodilla en el diagnóstico del dolor patelofemoral (DPF) causado por mal alineamiento patelar (MAP). Material y método. Se realizaron 25 RM en pacientes con DPF en los cuales se sospechó de MAP como causa y 25 en pacientes sin DPF (grupo control). Se midieron: distancia surco intertroclear-tuberosidad anterior tibial (SIT-TAT) y los ángulos de: Laurin modificado, Merchant y Troclear. Análisis estadístico con los test de ANOVA, Fischer y Pearson. Resultados. Hubo diferencias significativas entre los pacientes con DPF vs. grupo control en relación a: distancia SIT-TAT (11,79 mm vs. 9,35 mm, p = 0,002), ángulo de Laurin modificado (12,17° vs. 15,56°, p = 0,05) y ángulo Troclear (139° vs. 130,02°, p = 0,049). Respecto al ángulo de Merchant no hubo diferencias significativas. La distancia SIT-TAT tuvo un valor predictivo positivo (VPP) del 70% para DPF, con una sensibilidad del 51,61% y una especificidad del 53,33%. El ángulo de Laurin modificado tuvo un VPP del 77,78% para DPF, con una sensibilidad del 28% y una especificidad del 92%. El ángulo Troclear tuvo un VPP del 85,71% para DPF, con una sensibilidad del 24% y una especificidad del 96%. Conclusiones. La RM en 20° de flexión puede confirmar el MAP como causa de DPF. La determinación de alteraciones de la distancia SIT-TAT, báscula patelar y ángulo Troclear se correlaciona positivamente con la presencia del DPF, sugiriendo que este es causado por un mal alineamiento leve (AU)

Objectives. The aim of this study is to evaluate the usefulness of Magnetic Resonance Imaging (MRI) at 20° of knee flexion in patients with patellofemoral pain syndrome (PFPS) caused by suspected patellofemoral malalignment (PFM). Material and method. Fifty MRIs were performed on 25 patients with PFPS secondary to suspected PFM based on clinical examination, and on 25 patients without PFPS (control group). Measurements were made of tibial tuberosity-trochlear groove distance (TTTG) and modified Laurin, Merchant and trochlear angles. The results were analyzed with ANOVA and Fischer tests. Pearson correlation coefficients were used to analyze differences between PFPS and control cases. Specificity, sensitivity, positive predictive value and negative predictive value for knee pain were documented. Results. Significant differences were observed between PFPS and control groups in TTTG (11.79 mm vs. 9.35 mm; P=.002), Laurin angle (12.17° vs. 15.56°; P=.05), and trochlear angle (139° vs. 130.02°; P=.049). No differences were found between groups as regards the Merchant angle (P=.5). TTTG was 70% predictive of PFPS; however, it was only 53.33% specific, with a sensitivity of 51.61% for PFPS. Laurin angle was 77.78% predictive of PFPS, with a specificity of 92% and a sensitivity of 28%. Trochlear angle was 85.71% predictive of PFPS, with a specificity of 96% and a sensitivity of 24%. Conclusions. MRI can confirm clinically suspected PFPS secondary to malalignment. MRI determination of TTTG, patellar tilt, and trochlear angle correlates positively with clinical diagnosis of PFPS, suggesting that PFPS is caused by subtle malalignment (AU)

Maquet III procedure: what remains after initial complications--long-term results.

BACKGROUND: Maquet III procedure, unloved due to its complications (2% to 59%), has been progressively abandoned. At long-term follow-up, what happens to patients with complications that exceeded the initial ones (Acta Orthop Scand 60:20, 1989)? We retrospectively studied patients who were submitted to Maquet III procedure, by functional and radiologic long-term outcomes, in order to determine if this surgery has or has not fulfilled its initially proposed objectives. From 1970 to 1991, 116 patients benefit from the Maquet III procedure. From this, we were able to review in 2011, 23 patients (25 knees) who went through a single Maquet III procedure. Of these patients, 52% were males. Age at surgery was 39.7 ± 11.4, with a postoperative follow-up of 27.2 ± 3.1 years. METHODS: A questionnaire has been prepared for collecting data, and it has been supplemented by clinical records. We evaluated the preoperative complaints, postoperative complications, and range of motion during the recovery time, as well as the postoperative pain-absence period. All patients underwent an objective assessment using the visual analog scale (VAS) at rest and activity, and the Kujala patellofemoral scoring system. A radiological assessment was also made in order to evaluate the arthrosis degree. The bicondylo-patellar angle described by Delgado-Martins (Arch Orthop Traumat Surg 96:303-304, 1980) was used to measure patellar tilt, and the Caton-Deschamps index to calculate the patellar height. RESULTS: Only one knee had benefited from a total knee arthroplasty (20 years after the Maquet III procedure). Preoperative complains were mainly anterior knee pain, crepitus, and patellar instability. Nowadays, 10 patients (40%) still are pain free. Others had an average period without pain of 19.1 ± 6.1 years. VAS at rest was 1.7 ± 0.7 and in activity 4.4 ± 3.0. KPS was 61.9 ± 22.3 points. X-ray shows that 40% had a Kellgren-Lawrence grade of 1 at the patellofemoral joint. CONCLUSION: Maquet proposed this technique for knee-pain relief, maintenance of the knee range of motion, and for slowly progressive osteoarthritic development. Viewed in a dispassionately way, we could notice that the initial objectives of this procedure were completely achieved. A part of 80% of the initial population was lost during follow-up, which may compromise the conclusions, perhaps, it is time to reflect again on this solution, so unloved by so many.

Clinically insignificant association between anterior knee pain and patellofemoral lesions which are found incidentally.

BACKGROUND: Patellofemoral chondral lesions are frequently identified incidentally during the arthroscopic treatment of other knee pathologies. A role has been described for arthroscopic debridement when symptoms are known to originate from pathology of the patellofemoral joint. However, it remains unclear how to manage lesions which are found incidentally whilst tackling other pathologies. The purpose of this study was to establish the strength of association between anterior knee pain and patellofemoral lesions identified incidentally in a typical arthroscopic population. METHODS: A consecutive series of patients undergoing arthroscopy for a range of standard indications formed the basis of this cross section study. We excluded those with patellofemoral conditions in order to identify patellofemoral lesions which were solely incidental. Pre-operative assessments were performed on 64 patients, where anterior knee pain was sought by three methods: an annotated photographic knee pain map (PKPM), patient indication with one finger and by palpated tenderness. A single blinded surgeon, performed standard arthroscopies and recorded patellofemoral lesions. Statistical correlations were performed to identify the association magnitude. RESULTS: Associations were identified between incidental patellofemoral lesions and tenderness palpated on the medial patella (P = 0.007, χ(2) = 0.32) and the quadriceps tendon (P = 0.029, χ(2) = 0.26), but these associations were at best fair, which could be interpreted as clinically insignificant. CONCLUSION: Incidental patellofemoral lesions are not necessarily associated with anterior knee pain, we suggest that they could be left alone. This recommendation is only applicable to patellofemoral lesions which are found incidentally whilst addressing other pathology.

Correlation between subcutaneous knee fat thickness and chondromalacia patellae on magnetic resonance imaging of the knee.

PURPOSE: Chondromalacia patellae is a common cause of anterior knee pain in young patients and can be detected noninvasively with magnetic resonance imaging (MRI). The purpose of our study was to evaluate the correlation between subcutaneous fat thickness around the knee joint on axial MRIs as a surrogate marker of obesity, with the presence or absence of chondromalacia patellae. METHODS: A retrospective review was conducted of knee MRIs in 170 patients who satisfied the inclusion criteria. Imaging was performed over a 12-month period on a 1.5T MRI system with a dedicated extremity coil. Two radiologists experienced in musculoskeletal imaging assessed each examination in consensus for the presence or absence of chondromalacia patellae and graded positive studies from 0 (absent) to 3 (full cartilage thickness defect). Measurement of subcutaneous knee fat thickness was obtained on the medial aspect of the knee. RESULTS: MRI findings of chondromalacia patellae were present in 33 patients (19.4%), of which, there were 11 grade 1 lesions (33.3%), 9 grade 2 lesions (27.3%), and 13 grade 3 lesions (39.4%). The mean subcutaneous knee fat thickness was significantly higher in the chondromalacia patellae group for all grades compared with the normal group (P < .001), and there was a significant correlation between subcutaneous knee fat thickness and grades of chondromalacia patellae (R = 0.48 [95% confidence interval, 0.38-0.68]; P < .001). Female patients had thicker subcutaneous knee fat and more severe grades of chondromalacia patellae. CONCLUSION: Subcutaneous knee fat thickness as a surrogate marker of obesity was positively associated with the presence and severity of chondromalacia patellae on MRI.

[Unsatisfactory long-term prognosis of conservative treatment of patellofemoral pain syndrome]. / Utilfredsstillende langtidsresultater efter konservativ behandling af patellofemoralt smertesyndrom.

This review overviews the long-term prognosis of conservatively treated patients with patellofemoral pain syndrome (PFPS). Median values of the 16 included studies show that 29% of soldiers, 27.8% of sports active and 24,7% of the general public will become pain free after they are diagnosed with PFPS. 21.5% of sports active and 23% of the general public diagnosed with PFPS will stop participating in sports because of knee pain. There is an indication that around one third diagnosed with PFPS will become pain free and one fourth will stop participating in sports because of knee pain.

The role of autologous chondrocyte implantation in the treatment of symptomatic chondromalacia patellae.

PURPOSE: Chondromalacia patella is a distinct clinical entity of abnormal softening of the articular cartilage of the patella, which results in chronic retropatellar pain. Its aetiology is still unclear but the process is thought to be a due to trauma to superficial chondrocytes resulting in a proteolytic enzymic breakdown of the matrix. Our aim was to assess the effectiveness of autologous chondrocyte implantation on patients with a proven symptomatic retropatellar lesion who had at least one failed conventional marrow-stimulating therapy. METHODS: We performed chondrocyte implantation on 48 patients: 25 received autologous chondrocyte implantation with a type I/III membrane (ACI-C) method (Geistlich Biomaterials, Wolhusen, Switzerland), and 23 received the Matrix-assisted Chondrocyte Implantation (MACI) technique (Genzyme, Kastrup, Denmark). RESULTS: Over a mean follow-up period of 40.3 months, there was a statistically significant improvement in subjective pain scoring using the visual analogue scale (VAS) and objective functional scores using the Modified Cincinnati Rating System (MCS) in both groups. CONCLUSIONS: Chondromalacia patellae lesions responded well to chondrocyte implantation. Better results occurred with MACI than with ACI-C. Excellent and good results were achieved in 40% of ACI-C patients and 57% of MACI patients, but success of chondrocyte implantation was greater with medial/odd-facet lesions. Given that the MACI procedure is technically easier and less time consuming, we consider it to be useful for treating patients with symptomatic chondral defects secondary to chondromalacia patellae.

La influencia de la superficie articular y la membrana sinovial en la evolución de pacientes afectos por bloqueo crónico de la articulación temporomandibular tratados mediante artroscopia / Influence of the joint surface and the synovial membrane on the evolution of patients affected by chronic temporomandibular joint block who were treated with arthroscopic surgery

Introducción: Se ha referido la artroscopia de la articulación temporomandibular (ATM)como una técnica efectiva en el tratamiento del bloqueo crónico (BC) articular. El propósitodel presente estudio es evaluar si el estado de la superficie articular y la membrana sinovial directamente visualizados por artroscopia pueden determinar el resultado posoperatorio de pacientes afectos por BC de la ATM. Pacientes y método: Doscientos cincuenta y siete de 500 pacientes (344 articulaciones) cumplieronlos criterios de inclusión para BC de la ATM. Para el presente estudio se seleccionaron 172 pacientes con afectación unilateral. Se eligieron los parámetros "sinovitis" y "condromalacia" para la evaluación de la membrana sinovial y la superficie articular, respectivamente. Se establecieron dos grupos de pacientes: a) pacientes con afectación leve: sinovitisgrados I/II más condromalacia I/II, y b) pacientes con afectación grave: sinovitis gradosIII/IV más condromalacia grados III/IV. Se eligieron el dolor y la máxima apertura oral(MAO) interincisal como variables dependientes. Todos los pacientes se revisaron de modo posoperatorio al mes, 3, 6, 12 y 24 meses. Se utilizó la prueba de la “t” de Student paramuestras pareadas para comparar los valores medios de dolor (escala visual analógica, EVA) y función (MAO), de modo preoperatorio y posoperatorio. Se utilizó la “t” de Student para muestras independientes para la comparación de los diferentes grupos establecidos.Se consideró estadísticamente significativo un valor de p <= 0,05. Resultados: Artroscópicamente se observó sinovitis grados I/II en 87 (50,58%) pacientes, y sinovitis grados III/IV en 72 (41,86%), mientras que se objetivó condromalacia grados I/IIen 66 (38,37%) pacientes y condromalacia grados III/IV en 54 (31,39%)...(AU)

Introduction: Arthroscopy of the temporomandibular joint (TMJ) has been considered aneffective technique to treat close lock (CL). The purpose of this study is to evaluate if thestatus of the joint surface and the synovial membrane directly seen via arthroscopy candetermine the post operative results of patients with chronic block of the TMJ. Patients and methods: Two hundred and fifty-seven out of the 500 patients (344 joints) met thecriteria for chronic block of the TMJ. One hundred and seventy-two patients with unilateralaffectation were selected for this study. Synovitis and chondromalacia are the parameters chosen to evaluate the synovitis membrane and joint surface, respectively. Two groups ofpatients were formed: a) patients with light affectation: level I/II synovitis and level I/II chondromalacia, and b) patients with severe affectation: level III/IV synovitis and level III/IV chondromalacia. The dependent variables were pain and interincisal maximum oralopening (MOO). All of the patients had post operative follow-up at 1, 3, 6, 12, and 24 months.The "t" Student test was used before and after surgery to match evidence to compare the average values of visual analogical scale (VAS) and function (MOO). The "t" Student test wasused for independent samples to compare the different groups that were established. Avalue of p <= 0.05 was considered statistically significant. Results: Level I/II synovitis was seen using arthroscopy in 87 (50.58%) patients, and level III/IV synovitis was seen in 54 (31.39%) of patients, while level I/II chondromalacia was observed in 66 (38.37%) patients and level III/IV chondromalacia was observed in 54 (31.39%).During the follow-up period a significant decrease in pain and a parallel increase in oral opening were observed after arthroscopy in patients affected by level I/II and III/IV synovitis and level I/II and III/IV chondromalacia (AU)

Retropatellar chondromalacia associated with medial osteoarthritis after meniscus injury. One year of observations in sheep.

BACKGROUND/AIMS: In an ovine meniscal repair model, the patellofemoral (PF) osteoarthritis due to a non-sutured tear or failed repair was investigated. METHODS: A radial meniscus tear was either sutured with polydioxanone (PDS), with a slow degrading polylactide long-term suture(LTS) or left without treatment. Knee joint cartilage in the PF and medial compartment was evaluated compared to normal knees (healthy controls). RESULTS: Retropatellar osteoarthritis in the non-sutured and sutured animals was intense in contrast to the control knees after 6 months in all groups (p < 0.001), and after 12 months in the PDS group (p < 0.001), LTS group and non-sutured animals (p < 0.05). CONCLUSION: Non-sutured meniscus tears and failed repair lead fast to intense PF osteoarthritis corresponding with tibial damage of the injured compartment.

[Preliminary study on treating patellar instability guided by arthroscopy].

OBJECTIVE: To explore the operation method in treating patellar instability guided by arthroscopy and to evaluate its therapeutic effects. METHODS: Thirty-two patients (34 knees) with patellar instability including 2 patellar tilt (2 knees), 26 (27 knees) patellar subluxation, and 4 (5 knees) patellar dislocation, diagnosed by clinical and arthroscopical standard, were treated with anterior transfer of the gracilis or medial transfer of the tibial tuberosity based on the lateral retinacular release and medial tightening. RESULTS: Twenty-eight patients were followed up for 5-87 (mean 36.6) months. The excellence rates was 92.8%. CONCLUSION: The patellofemoral alignment can be seen directly and dynamically under the arthroscopy. The combinational treatment including anterior transfer of the gracilis in repairing patellar instability can avoid the recurrence effectively and get satisfactory results.

The pathophysiology of patellofemoral pain: a tissue homeostasis perspective.

UNLABELLED: Fundamental to rational, safe, and effective treatment for any orthopaedic condition is an accurate understanding of the etiology of the symptoms. The decades-old paradigm of a pure structural and biomechanical explanation for the genesis of patellofemoral pain is giving way to one in which biologic factors are being given more consideration. It is increasingly evident that a variable mosaic of possible pathophysiologic processes, often caused by simple overload, best accounts for the etiology of patellofemoral pain in most patients. Inflamed synovial lining and fat pad tissues, retinacular neuromas, increased intraosseous pressure, and increased osseous metabolic activity of the patella all have been documented as contributing to the perception of anterior knee pain. Considered together, these processes can be characterized as loss of tissue homeostasis and can be seen as providing a new and alternative explanation for the conundrum of anterior knee pain. Certain high loading conditions of the patellofemoral joint can be of sufficient magnitude to induce the symptomatic loss of tissue homeostasis so that, once initiated, they may persist indefinitely. From this new biologic perspective, it clinically matters little what structural factors may be present in a given joint (such as chondromalacia, patellar tilt or a Q angle above a certain value) if the pain free condition of tissue homeostasis is safely achieved and maintained. LEVEL OF EVIDENCE: Level V (expert opinion). See the Guidelines for Authors for a complete description of levels of evidence.